Another Half a Year passes

SUBHEAD: Same old Wake-up time. If you can't smell the smoke yet... take another deep sniff.

By Juan Wilson -
(INSERT_LINK_BETWEEN_PARENTHESES)


Image above: From ()

We trust you have buckled down and are anticipating that time when the gas stations and supermarkets are empty. Trust me... that time has just over an upcoming horizon. 

If you are not collecting rainwater, don't have a water well,  are not growing much of your own veggies and don't have a chicken coop (for eggs & meat) then you could get into some serious trouble when the farmers who use "supply ships" to stock Hawaii and can sell their all their crops without paying for the long Trans-Pacific shipping.

Despite how many "climate change observers" are in denial, it is obvious to me that the whole system of climate stability the expected results, will fall by the wayside.

If you have not lately  taken a look at climate warming, and the crucial environmental conditions necessary to allow the human population to quadruple in the last half century;  then as Mr. T (born Laurence Tureaud, May 21, 1952) said:

         "I pity the fool!" 

Here in Hawaii we have not yet seen catastrophically high temperatures or failures of rainfall in the crucial food growing areas that re experiencing environmental collapse... but it is a real possibility. Here on Kauai we have had an unusual low lying  ring cumulus clouds 360 degrees around our horizon with otherwise sunny skies.

It rained less than normal last winter. And  there is no reason to think it will be otherwise this coming winter. As the Pacific Ocean warms the clouds over Hawaii they will rise to higher altitude... meaning the rain clouds will be a little higher in altitude and miss supplying the water to all 5 of the of the only rivers in the state of Hawaii.

Much of Hawaii has been blessed for a long line with gentle climes. That is about to change, whether we like it or not... even if we are avid gardeners and living off the "grid" with our own water well powered by photovoltaic solar panels... the clouds will cease and the water table will drop.

When the shit hits the fan you will want to be in the greenest, wettest, sunniest place you can find inhabited by friendly like minded people. 

I hope you are there now. It takes a while to get it right, and there is not a lot of time left for Costco Walmart and Home Depot.

I am going to try and get back on a regular schedule of posting. The biggest hang-ups are difficulties getting the illustrations the way I want them it is much harder than it used to be... I know... picky... but that's important to me...

 

Whither do we go?

SUBHEAD: What will you be doing when you cannot be where you are doing what you do now.

By Juan Wilson on 1 February 2020 for Island Breath -
(https://islandbreath.blogspot.com/2020/02/whither-do-we-go.html)


Image above: Napa Road Ends. If we could only be so lucky. From (https://www.adsoftheworld.com/media/print/napa_road_ends_2).

If you have been paying attention it should be pretty obvious now... we are much like Wile E. Coyote, from the Warner Brothers' Luney Tunes "Roadrunner" cartoon series. The coyote would chase the roadrunner in order to kill and eat him.

The coyote wants to eat the roadrunner, but the roadrunner was to fast and agile for him. The coyote would then purchase some manufactured equipment from a company called ACME (A Company that Makes Everything). His order would often include items like catapults, anvils, dynamite, springs, bear traps or other deadly materials to capture and kill the roadrunner when he stops to eat some birdseed bait.

The traps never worked as expected and the disappointed coyote usually would then test the equipment to see why it failed. Needless to say, the coyote would set off the trigger to the trap and end up crushed by an anvil or catapulted off a cliff.

And this is where I see humanity today. We have employed technology (agriculture, industrialization, computers, etc.) to feed us, lesson our load, and solve our problems... and that is our problem.

We have been so successful in this endeavor that all that remains of nature are human settlements and what they consume. As far as humans are concerned that is all that matters.

Unfortunately that has shown itself to be a dead end road and we are at the end of it... There may be another road we can take but we will have to reduce our numbers and consumption of resources by some orders of magnitude to get there.

We have shown ourselves to be too self-absorbed and greedy to even attempt to meet the goal of sustainability even after the scientific report "A Limit to Growth" by the Club of Rome a half century ago demonstrated we were about to crash life on planet Earth.

Well we are well on the way extinguishing the forests, killing the oceans and melting the polar ice. We have exterminated all but a few wild creatures and will only permit what we eat or put in captivity to live.

We won!

Now what?

If there are any human survivors to the conflagration we are about two witness they will have to begin again as we have in the past. See "Once Through the Bottleneck" - subtitled "Almost 200,000 years ago humans faced extinction. Only a few hundred were saved along the coast of Cape Horn".  

In my opinion we will be lucky if there are even a few settlements of humans that get through the  coming bottleneck. It is hard to say what might be an oasis through the coming changes.

But be warned - it may be already past time to have any choices as to where you will be, and what you will be doing when you cannot be where you are doing what you do now.

As John Michael Greer has written:

• "The Long Descent: A User's Guide to the End of the Industrial Age" (2008) 
• "Not the Future we Ordered: Peak Oil, Psychology and the Myth of Progress" (2013) 
• "Collapse Now and Avoid the Rush: the Best of the Archdruid Report" (2015) 
• "Dark Age America: Climate Change, Cultural Collapse, the Hard Future Ahead" (2016) 
• "The Retro Future: Looking to the Past to Remake the Future" (2017) 

To see Greer's blog visit (https://www.ecosophia.net)

Some of the Lights On

SUBHEAD: We should be redefining Energy Security as keeping at least "Some of the Lights On".

By Kris De Decker on 10 December 2018 for Low-Tech Magazine -
(https://www.lowtechmagazine.com/2018/12/keeping-some-of-the-lights-on-redefining-energy-security.html)


Image above: Keeping some of the lightbulbs on is better than all or nothing. From (http://www.womeninaction.co.za/be-different-to-make-a-difference/).

What is Energy Security?
What does it mean for a society to have “energy security”? Although there are more than forty different definitions of the concept, they all share the fundamental idea that energy supply should always meet energy demand. This also implies that energy supply needs to be constant – there can be no interruptions in the service. [1-4]

For example, the International Energy Agency (IEA) defines energy security as “the uninterrupted availability of energy sources at an affordable price”, the US Department of Energy and Climate Change (DECC) defines the concept as meaning that “the risks of interruption to energy supply are low”, and the EU defines it as a “stable and abundant supply of energy”. [5-7]

Historically, energy security was achieved by securing access to forests or peat bogs for thermal energy, and to human, animal, wind or water power sources for mechanical energy. With the arrival of the Industrial Revolution, energy security came to depend on the supply of fossil fuels.

As a theoretical concept, energy security is most closely related to the oil crises from the 1970s, when embargoes and price manipulations limited oil supply to Western nations.

As a result, most industrialised societies still stockpile oil reserves that are equivalent to several months of consumption.

Although oil remains as vital to industrial economies as it was in the 1970s, mainly for transportation and agriculture, it’s now recognised that energy security in modern societies also depends on other infrastructures, such as those supplying gas, electricity, and even data.

Furthermore, these infrastructures increasingly interconnect and depend on each other.

For example, gas is an important fuel for power production, while the power grid is now required to operate gas pipelines. Power grids are needed to run data networks, and data networks are now needed to run power grids.

This article investigates the concept of energy security by focusing on the power grid, which has become just as vital to industrial societies as oil. Moreover, electrification is seen as a way to decrease dependency on fossil fuels – think electric vehicles, heat pumps, and wind turbines.

The “security” or “reliability” of a power grid can be measured precisely by indicators of continuity such as the “Loss-of-Load Probability” (LOLP), and the “System Average Interruption Duration Index” (SAIDI). Using these indicators, one can only conclude that power grids in industrial societies are very secure.

For example, in Germany, power is available for 99.996% of the time, which corresponds to an interruption in service of less than half an hour per customer per year. [8]

Even the worst performing countries in Europe (Latvia, Poland, Lithuania) have supply shortages of only eight hours per customer per year, which corresponds to a reliability of 99.90%. [8]

The US power grid is in between these values, with supply interruptions of less than four hours per customer per year (99.96% reliability). [9]

How Secure is a Renewable Power Grid?
In the current operation of infrastructures, the paradigm is that consumers could and should have access to as much electricity, gas, oil, data or water as they want, anytime they want it, for as long as they want it.

The only requirement is that they pay the bill. Looking at the power sector, this vision of energy security is quite problematic, for several reasons.

First of all, most energy sources from which electricity is made are finite – and maintaining a steady supply of something that’s finite is of course impossible. In the long run, the strategy to maintain energy security is certainly doomed to fail. In the shorter term, it may disrupt the climate and provoke armed conflicts.

The International Energy Agency (IEA), which was set up following the first oil crisis in the early 1970s, encourages the use of renewable energy sources in order to diversify the energy supply and improve energy security in the long term.

A renewable power system is not dependent on foreign energy imports nor vulnerable to fuel price manipulations – which are the main worries in an energy infrastructure that is largely based on fossil fuels.

Of course, solar panels and wind turbines have limited lifetimes and need to be manufactured, which also requires resources that could come from abroad or which can become depleted. But, once they are installed, renewable power systems are “secure” in a way and for a period of time that fossil fuels (and atomic energy) are not.

Furthermore, solar and wind power provide more security concerning physical failure or sabotage, even more so when renewable power production is decentralised. Renewable power plants also have lower CO2-emissions, and the extreme weather events caused by climate change are a risk to energy security as well.

However, in spite of all these advantages, renewable energy sources pose fundamental challenges to the current understanding of energy security.

Most importantly, the renewable energy sources with the largest potential – sun and wind – are only intermittently available, depending on the weather and the seasons.

This means that solar and wind power don’t match the criterium that all definitions of energy security consider to be essential: the need for an uninterrupted, unlimited supply of power.

The reliability of a power grid with a high share of solar and wind power would be significantly below today’s standards for continuity of service. [10-14]

In such a renewable power grid, a 24/7 power supply can only be maintained at very high costs, because it requires an extensive infrastructure for energy storage, power transmission, and excess generation capacity.

This additional infrastructure risks making a renewable power grid unsustainable, because above a certain threshold, the fossil fuel energy used for building, installing and maintaining this infrastructure becomes higher than the fossil fuel energy saved by the solar panels and the wind turbines.

Intermittency is not the only disadvantage of renewable energy sources. Although many media and environmental organisations have painted a picture of solar and wind power as abundant sources of energy (“The sun delivers more energy to Earth in an hour than the world consumes in a year”), reality is more complex.

The “raw” supply of solar (and wind) energy is enormous indeed.

However, because of their very low power density, to convert this energy supply into a useful form solar panels and wind turbines require magnitudes of order more space and materials compared to thermal power plants – even if the mining and distribution of fuels is included. [15]

Therefore, a renewable power grid cannot guarantee that consumers have access to as much electricity as they want, even if the weather conditions are optimal.


How Secure is an Off-the-Grid Power System?
Today’s energy policies related to electricity try to reconcile three aims: an uninterrupted and limitless supply of power, affordability of electricity prices, and environmental sustainability.

A power grid that is mainly based on fossil fuels and atomic energy cannot achieve the aim of environmental sustainability, and it can only achieve the other goals as long as foreign suppliers do not cut off supplies or raise energy prices (or as long as national or international reserves are not depleted).

However, a renewable power grid cannot reconcile these three goals either. To achieve an unlimited 24/7 supply of power, the infrastructure needs to be oversized, which makes it expensive and unsustainable.

Without that infrastructure, a renewable power grid could be affordable and sustainable, but it could never offer an unlimited 24/7 supply of power.

Consequently, if we want a power infrastructure that is affordable and sustainable, we need to redefine the concept of energy security – and question the criterium of an unlimited and uninterrupted power supply.

If we look beyond the typical large-scale central infrastructures in industrial societies, it becomes clear that not all provisioning systems offer a limitless supply of resources.

Off-the-Grid microgeneration – the local production and storage of electricity using batteries and solar PV panels or wind turbines – is one example.

In principle, off-the-grid systems can be sized in such a way that they are “always on”. This can be done by following the “worst-month method”, which oversizes generation and storage capacity so that supply can meet demand even during the shortest and darkest days of the year.

However, just like in an imaginary large-scale renewable power grid, matching supply to demand at all times makes an off-the-grid system very costly and unsustainable, especially in high seasonality climates. [16-18]

Therefore, most off-the-grid systems are sized according to a method that aims for a compromise between reliability, economic cost and sustainability. The “loss-of-load probability sizing method” specifies a number of days per year that supply does not match demand. [19-21]

n other words, the system is sized, not only according to a projected energy demand, but also according to the available budget and/or the available space.

Sizing an off-the-grid power system in this way generates significant cost reductions, even if “reliability” is reduced just a little bit.

For example, a calculation for an off-the-grid house in Spain shows that decreasing the reliability from 99.75% to 99.00% produces a 60% cost reduction, with similar benefits for sustainability. Supply would be interrupted for 87.6 hours per year, compared to 22 hours in the higher reliability system. [16]

According to the current understanding of energy security, off-the-grid power systems that are sized in this way are a failure: energy supply doesn’t always meet energy demand.

However, off-gridders don’t seem to complain about a lack of energy security, on the contrary. There’s a simple reason for this: they adapt their energy demand to a limited and intermittent power supply.

In their 2015 book Off-the-Grid: Re-Assembling Domestic Life, Phillip Vannini and Jonathan Taggart document their travels across Canada to interview about 100 off-the-grid households. [22]

Among their most important observations is that voluntary off-gridders use less electricity overall and routinely adapt their energy demand to the weather and the seasons.

For example, washing machines, vacuum cleaners, power tools, toasters or videogame consoles are not used at all, or they are only used during periods of abundant energy, when batteries can accommodate no further charge.

If the sky is overcast, off-gridders act differently to draw less power and have some more left over for the day after.

Vannini and Taggart also observe that voluntary off-gridders seem to feel perfectly happy with levels of lighting or heating that are different from the standards that many in the western world have come to expect. Often, this shows itself in concentrating activities around more localised sources of heat and light. [22]

Similar observations can be made in places where people – involuntarily – depend on infrastructures that are not always on.

If centralised water, electricity and data networks are present in less industrialised countries, they are often characterised by regular and irregular interruptions in the supply. [23-25]

However, in spite of the very low reliability of these infrastructures – according to common indicators of continuity – life goes on.

Daily household routines are shaped around disruptions of supply systems, which are viewed as normal and a largely accepted part of life.

For example, if electricity, water or Internet are only available during certain times of the day, household tasks or other activities are planned accordingly. People also use less energy overall: the infrastructure simply doesn’t allow for a resource-intensive lifestyle. [23]
 
More Reliable, Less Secure?
The very high “reliability” of power grids in industrial societies is justified by calculating the “value of lost load” (VOLL), which compares the financial loss due to power shortages to the extra investment costs to avoid these shortages. [1][10] [26-29]

However, the value of lost load is highly dependent on how society is organised. The more it depends on electricity, the higher the financial losses due to power shortages will be.

Current definitions of energy security consider supply and demand to be unrelated, and focus almost entirely on securing energy supply.

However, alternative forms of power infrastructures like those described above show that people adapt and match their expectations to a power supply that is limited and not always on. In other words, energy security can be improved, not just by increasing reliability, but also by reducing dependency on energy.

Demand and supply are also interlinked, and mutually influence each other, in 24/7 power systems – but with the opposite effect. Just like “unreliable” off-the-grid power infrastructures foster lifestyles that are less dependent on electricity, “reliable” infrastructures foster lifestyles that are increasingly dependent on electricity.

In their 2018 book Infrastructures and Practices: the Dynamics of Demand in Networked Societies, Olivier Coutard and Elizabeth Shove argue that an unlimited and uninterrupted power supply has enabled people in industrial societies to adopt a multitude of power dependent technologies – such as washing machines, air conditioners, refrigerators, automatic doors, or 24/7 mobile internet access – which become “normal” and central to everyday life.

At the same time, alternative ways of doing things – such as washing clothes by hand, storing food without electricity, keeping cool without air-conditioning, or navigating and communicating without mobile phones – have withered away, or are withering away. [30]

As a result, energy security is in fact higher in off-the-grid power systems and “unreliable” central power infrastructures, while industrial societies are the weakest and most fragile in the face of supply interruptions.

What is generally assumed to be a proof of energy security – an unlimited and uninterrupted power supply – is actually making industrial societies ever more vulnerable to supply interruptions: people increasingly lack the skills and the technology to function without a continuous power supply.

Redefining Energy Security
To arrive to a more accurate definition of energy security requires the concept to be defined, not in terms of commodities like kilowatt-hours of electricity, but in terms of energy services, social practices, or basic needs. [1]

People don’t need electricity in itself. What they need, is to store food, wash clothes, open and close doors, communicate with each other, move from one place to another, see in the dark, and so on.

All these things can be achieved either with or without electricity, and in the first case, with more or less electricity.

Defined in this way, energy security is not just about securing the supply of electricity, but also about improving the resilience of the society, so that it becomes less dependent on a continuous supply of power.

This includes the resilience of people (do they have the skills to do things without electricity?), the resilience of devices and technological systems (can they handle an intermittent power supply?), and the resilience of institutions (is it legal to operate a power grid that is not always on?).

Depending on the resilience of the society, a disruption of the power supply may or may not lead to a disruption of energy services or social practices.

For example, although our food distribution system is dependent on a cold chain that requires a continuous power supply, there are many alternatives.

We could adapt refrigerators to an irregular power supply by insulating them much better, we could reintroduce cold cellars (which keep food fresh without electricity), or we could relearn older methods of food storage, like fermentation.

We could also improve people’s skills in terms of fresh cooking, switch to diets based on ingredients that don’t need cold storage, and encourage local daily shopping over weekly trips to large supermarkets.

If we look at energy security in a more holistic way, taking into account both supply and demand, it quickly becomes clear that energy security in industrial societies continues to deteriorate. We keep delegating more and more tasks to machines, computers and large-scale infrastructures, thus increasing our dependency on electricity.

Furthermore, the Internet is becoming just as essential as the power grid, and trends like cloud computing, the Internet of Things, and self-driving cars are all based on several interconnected layers of continuously operating infrastructures.


Because demand and supply influence each other, we come to a counter-intuitive conclusion: to improve energy security, we need to make the power grid less reliable. This would encourage resilience and substitution, and thus make industrial societies less vulnerable to supply interruptions.

Coutard and Shove argue that “it would make sense to pay more attention to opportunities for innovation that are opened when large network systems are weakened and abandoned, or when they become less reliable”. They add that the experiences of voluntary off-gridders “provide some insights into the types of configuration at stake”. [30]

Arguing for a less reliable power supply is sure to be controversial. In fact, “Keeping the lights on” is a phrase that is often used to justify energy reforms such as building more atomic plants, or keeping them in operation past their planned lifetimes.

To achieve real energy security, “keeping the lights on” should be replaced by phrases like “keeping some of the lights on”, “which lights should we turn off next?”, or “what’s wrong with a bit more dark?”. [31]

Obviously, a less reliable energy supply would bring fundamental changes to routines and technologies, whether it is in households, factories, transport systems, or communications networks – but that’s exactly the point. Present ways of life in industrial societies are simply not sustainable.

Sources
[1] Winzer, Christian. "Conceptualizing energy security." Energy policy 46 (2012): 36-48. https://www.repository.cam.ac.uk/bitstream/handle/1810/242060/cwpe1151.pdf?sequence=1&isAllowed=y

[2] Sovacool, Benjamin K., and Ishani Mukherjee. "Conceptualizing and measuring energy security: A synthesized approach." Energy 36.8 (2011): 5343-5355. https://relooney.com/NS4053-Energy/00-Energy-Security_1.pdf

[3] Kruyt, Bert, et al. "Indicators for energy security." Energy policy37.6 (2009): 2166-2181. https://www.sciencedirect.com/science/article/pii/S0301421509000883

[4] Cherp, Aleh, and Jessica Jewell. "The concept of energy security: Beyond the four As." Energy Policy 75 (2014): 415-421. https://www.sciencedirect.com/science/article/pii/S0301421514004960

5] Energy security, International Energy Agency. https://www.iea.org/topics/energysecurity/

[6] Lucas, Javier Noel Valdés, Gonzalo Escribano Francés, and Enrique San Martín González. "Energy security and renewable energy deployment in the EU: Liaisons Dangereuses or Virtuous Circle?." Renewable and Sustainable Energy Reviews 62 (2016): 1032-1046. https://www.researchgate.net/profile/Javier_Valdes4/publication/303361228_Energy_security_and_renewable_energy_deployment_in_the_EU_Liaisons_Dangereuses_or_Virtuous_Circle/links/5a536f45458515e7b72eab26/Energy-security-and-renewable-energy-deployment-in-the-EU-Liaisons-Dangereuses-or-Virtuous-Circle.pdf

[7] Strambo, Claudia, Måns Nilsson, and André Månsson. "Coherent or inconsistent? Assessing energy security and climate policy interaction within the European Union." Energy Research & Social Science 8 (2015): 1-12. https://www.sciencedirect.com/science/article/pii/S221462961500047X

[8] CEER Benchmarking Report 6.1 on the Continuity of Electricity and Gas Supply. Data update 2015/2016. Ref: C18-EQS-86-03. 26-July-2018. Council of European Energy Regulators. https://www.ceer.eu/documents/104400/-/-/963153e6-2f42-78eb-22a4-06f1552dd34c

[9] Average frequency and duration of electric distribution outages vary by states. U.S. Energy Information Administration (EIA). April 5, 2018. https://www.eia.gov/todayinenergy/detail.php?id=35652


[10] Röpke, Luise. "The development of renewable energies and supply security: a trade-off analysis." Energy policy 61 (2013): 1011-1021. https://www.econstor.eu/bitstream/10419/73854/1/IfoWorkingPaper-151.pdf

[11] "Evolutions in energy conservation policies in the time of renewables", Nicola Lablanca, Isabella Maschio, Paolo Bertoldi, ECEEE 2015 Summer Study -- First Fuel Now. https://www.eceee.org/library/conference_proceedings/eceee_Summer_Studies/2015/9-dynamics-of-consumption/evolutions-in-energy-conservation-policies-in-the-time-of-renewables/

[12] “How not to run a modern society on solar and wind power alone”, Kris De Decker, Low-tech Magazine, September 2017.

[13] Nedic, Dusko, et al. Security assessment of future UK electricity scenarios. Tyndall Centre for Climate Change Research, 2005. http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.461.4834&rep=rep1&type=pdf

[14] Zhou, P., R. Y. Jin, and L. W. Fan. "Reliability and economic evaluation of power system with renewables: A review." Renewable and Sustainable Energy Reviews 58 (2016): 537-547. https://www.sciencedirect.com/science/article/pii/S136403211501727X

[15] Smil, Vaclav. Power density: a key to understanding energy sources and uses. MIT Press, 2015. https://mitpress.mit.edu/books/power-density

[16] Landeira, Cristina Cabo, Ángeles López-Agüera, and Fernando Núñez Sánchez. "Loss of Load Probability method applicability limits as function of consumption types and climate conditions in stand-alone PV systems." (2018). https://www.researchgate.net/profile/Cristina_Cabo2/publication/324080184_Loss_of_Load_Probability_method_applicability_limits_as_function_of_consumption_types_and_climate_conditions_in_stand-alone_PV_systems/links/5abca9fa45851584fa6e1efd/Loss-of-Load-Probability-method-applicability-limits-as-function-of-consumption-types-and-climate-conditions-in-stand-alone-PV-systems.pdf

[17] Singh, S. Sanajaoba, and Eugene Fernandez. "Method for evaluating battery size based on loss of load probability concept for a remote PV system." Power India International Conference (PIICON), 2014 6th IEEE. IEEE, 2014. https://ieeexplore.ieee.org/abstract/document/7117729

[18] How sustainanle is stored sunlight? Kris De Decker, Low-tech Magazine.

[19] Chapman, R. N. "Sizing Handbook for Stand-Alone Photovoltaic." Storage Systems, Sandia Report, SAND87-1087, Albuquerque (1987). https://prod.sandia.gov/techlib-noauth/access-control.cgi/1987/871087.pdf

[20] Posadillo, R., and R. López Luque. "A sizing method for stand-alone PV installations with variable demand." Renewable Energy33.5 (2008): 1049-1055. https://www.sciencedirect.com/science/article/pii/S096014810700184X

[21] Khatib, Tamer, Ibrahim A. Ibrahim, and Azah Mohamed. "A review on sizing methodologies of photovoltaic array and storage battery in a standalone photovoltaic system." Energy Conversion and Management 120 (2016): 430-448. https://staff.najah.edu/media/published_research/2017/01/19/A_review_on_sizing_methodologies_of_photovoltaic_array_and_storage_battery_in_a_standalone_photovoltaic_system.pdf

[22] Vannini, Phillip, and Jonathan Taggart. Off the grid: re-assembling domestic life. Routledge, 2014. http://lifeoffgrid.ca/off-grid-living-the-book/

[23] "Materialising energy and water resources in everyday practices: insights for securing supply systems", Yolande Strengers, Cecily Maller, in "Global Environmental Change 22 (2012), pp. 754-763. http://researchbank.rmit.edu.au/view/rmit%3A17990/n2006038376.pdf

[24] Pillai, N. "Loss of Load Probability of a Power System." (2008). https://mpra.ub.uni-muenchen.de/6953/1/MPRA_paper_6953.pdf

[25] Al-Rubaye, Mohannad Jabbar Mnati, and Alex Van den Bossche. "Decades without a real grid: a living experience in Iraq." International Conference on Sustainable Energy and Environment Sensing (SEES 2018). 2018. https://biblio.ugent.be/publication/8566224

[26] Telson, Michael L. "The economics of alternative levels of reliability for electric power generation systems." The Bell Journal of Economics (1975): 679-694. https://www.jstor.org/stable/3003250

[27] Schröder, Thomas, and Wilhelm Kuckshinrichs. "Value of lost load: an efficient economic indicator for power supply security? A literature review." Frontiers in energy research 3 (2015): 55. https://www.frontiersin.org/articles/10.3389/fenrg.2015.00055/full

[28] Ratha, Anubhav, Emil Iggland, and Goran Andersson. "Value of Lost Load: How much is supply security worth?." Power and Energy Society General Meeting (PES), 2013 IEEE. IEEE, 2013. https://www.ethz.ch/content/dam/ethz/special-interest/itet/institute-eeh/power-systems-dam/documents/SAMA/2012/Ratha-SA-2012.pdf

[29] De Nooij, Michiel, Carl Koopmans, and Carlijn Bijvoet. "The value of supply security: The costs of power interruptions: Economic input for damage reduction and investment in networks." Energy Economics 29.2 (2007): 277-295.

[30] Coutard, Olivier, and Elizabeth Shove. "Infrastructures, practices and the dynamics of demand." Infrastructures in Practice. Routledge, 2018. 10-22. https://www.routledge.com/Infrastructures-in-Practice-The-Dynamics-of-Demand-in-Networked-Societies/Shove-Trentmann/p/book/9781138476165

[31] Demand Dictionary of Phrase and Fable, seventeenth edition. Jenny Rinkinen, Elizabeth Shove, Greg Marsden, The Demand Centre, 2018. http://www.demand.ac.uk/wp-content/uploads/2018/07/Demand-Dictionary.pdf


.

Time's up! Cease and Desist!

SUBHEAD: Be carbon neutral and shelter in place. The storm is about to descend upon us.

By Juan Wilson on 6 November 2018 for Island Breath -
(https://islandbreath.blogspot.com/2018/11/times-up-cease-and-desist.html)


Image above:Ted Kaczynski as an assistant professor at the University of California, Berkley in 1967... the Summer of Love. From (https://en.wikipedia.org/wiki/Ted_Kaczynski).

If you don't know about Ted Kaczynski you should. He was a young professor at UC Berkley in the late 1960's. Ted was a brilliant mathematician and observer of the scene.

After realizing the likely destruction of life on Earth due to modern industrialization he abandoned an academic career in 1969 to pursue a primitive lifestyle.

He moved to a remote cabin without electricity or running water near Lincoln, Nebraska, where he lived as a recluse while learning survival skills in an attempt to become self-sufficient.

After witnessing the destruction of the wilderness surrounding his cabin he became deranged and engaged in a terror campaign.  He became the Unabomber. Between 1978 and 1995, he killed three people and injured 23 others mailing explosives packages to those he deemed agents of the industrial destruction of nature. 

He issued a social critique in the form of a manifesto that he submitted to the New York Times and Washington Post opposing industrialization and advancing a nature-centered form of anarchism.

It's past time to come to grips with what Ted Kaczynski realized (before the Club of Rome Report) a half century ago.

In my opinion he was right about the industrial destruction - but he was wrong about fixing things by mailing bombs. My advice...

"Cease and Desist!"
A cease and desist order is sent to individuals or businesses to stop purportedly illegal or undesirable activity ("cease") and not to restart it ("desist").

Yes, this means you (and me)!

This article is not meant to be a warning. It's an instruction. Immediately cease and desist all activities producing a net loss of thriving biosphere.

To the degree that is possible stop eating packaged food, stop using disposable products, stop going places you are not needed, stop depending on the power-grid and information networks for all your information and entertainment... including this blog.

"Be Carbon Neutral!"
Make no net release of carbon dioxide to the atmosphere, especially through offsetting emissions by planting trees.

If what you are doing is not Carbon Neutral or better you are actively contributing to the near term extinction of life on Earth as we know it.

What this means is you personally achieving within the next two years a change in your life that will increase the living biosphere to a degree that outpaces your consumption of energy and natural resources.

"Shelter in Place!"
Already it is getting too late for many. If your not in a place that can be made self-sustaining it is already too late. Act now! Are there friends or relatives in sustainable places with whom you could contribute to a livable future? If so get in touch now.

If you are in a sustainable place, but not off the grid and growing your own food already, there is little time left. Act now! Get the tools you need. Plant the garden - Store fresh water - Capture energy. It take time and effort, with trials and errors, to make a place provide for life support. Get going!

The implications of the changes coming are massive.

• It would mean abandoning access to automobiles for the purpose daily commuting, errands,  shopping or recreation. 
• It would mean having an occupation, getting services, and obtaining food within walking distance from your home.
• It would mean changes in lifestyle that would include an end to regular air travel for business or pleasure. 
• It would mean an end to universal access to the Power Grid (most people would need to cleanly produce their own power).
• It would mean a return to small family farming for the vast majority of people (about 90% in America before World War One).  
• It would mean making and repairing the things you need in your daily life (meals, clothing, furniture, shelter.

My most optimistic future vision is one in which the future supports and sustains oases of biodiverse environments where living things can flourish. Including some humans. Each oasis may be far from one another, but an experienced traveler might wend their way from one to another.

My advice is to treat this information like a hurricane emergency alert that you find yourself in the path of. Act now and avoid the rush.

See also:
Ea O Ka Aina: Biodiversity loss is our extinction 11/6/18
Ea O Ka Aina: Earth • Water • Fire • Air 11/2/18
Ea O Ka Aina: Living in a Shitstorm 10/17/18
Ea O Ka Aina: What's Omitted from the IPCC Report 10/9/18
Ea O Ka Aina: Final Call to Save the World 10/8/18
Ea O Ka Aina: The Well-To-Do Wrecking the Climate 10/8/18
Ea O Ka Aina: Scientists Outline Paths to Survival 10/4/18
Ea O Ka Aina: Being Green is being a Terrorist 2/20/18
Ea O Ka Aina: 'Shrinking the Technosphere' review 12/30/17
Ea O Ka Aina: Find and Limit Ourselves 2/2/17
Ea O Ka Aina: Automation - whatta bitch! 1/4/17
Ea O Ka Aina: Planet Kaauai 2/26/16
Ea O Ka Aina: Oases on a future Eaarth 6/28/15
Ea O Ka Aina: Dark Ecology 2/2/13
Ea O Ka Aina: The Luddite Rebellion 11/14/12

Ea O Ka Aina: Embrace the Change 7/24/12

Island Breath: The Dead Zone 2/7/06

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The Off-Grid Poster Child

SUBHEAD: After the disaster of hurricane Maria, Puerto Rico is ripe to be the place to find stand-alone off-grid living.

By Juan Wilson on 20 September 2018 for Island Breath -
(http://islandbreath.blogspot.com/2018/09/off-grid-poster-child.html)


Image above: Electricity poles and lines lie toppled on the road after Hurricane Maria hit the eastern region of Puerto Rico. Photo: Carlos Giusti. From (https://www.wsj.com/articles/the-truth-about-hurricane-maria-1537129890).

Well before hurricane Maria devastated the island of Puerto Rico on 20 September 2017 the infrastructure of the power grid had deteriorated to the point of fragility not seen elsewhere in America.

That grid was the responsibility of The Puerto Rico Electric Power Authority (PREPA). PREPA is a government-owned corporation of Puerto Rico responsible for electricity generation, power distribution, and power transmission on the island. Hurricane Maria demonstrated that PREPA was a failure and that it would not have the vision or resources needed to serve Puerto Rico.

Without the resources to repair what had been a frail and failing system, Maria provided a death blow to PREPA. The Puerto Rican people tuned to gas operated electrical generators that had been purchased by people who could afford them for the frequent PREPA blackouts. After Maria things got nasty. Neighborhoods strung extension cords between homes in suburban neighborhoods. They got by with less.

There were some isolated small scaled solar photo-voltaic electric systems in place - and they became important. The Wall Street Journal reported (https://www.wired.com/story/puerto-rico-hurricane-maria-recovery/):

In the town rural town of Adjuntas, nestled in the mountains about an hour and a half southwest of San Juan, an NGO dedicated in part to solar power, called Casa Pueblo, became a pillar of the local recovery. 

When the town’s 18,000 residents were cut off from the rest of the island after Maria, the NGO’s solar-­powered radio helped authorities find out which roads were clear and which families were in danger, and attend to emergencies when the central government and federal authorities were not yet responding. 

Casa Pueblo subsequently gave out some 14,000 solar-powered lamps and also offered a solar-charged satellite phone at its offices for locals to use. At any given time, five to 10 people waited to make a call.

Arturo Massol, the associate director of Casa Pueblo and an ardent evangelist for decentralized, renewable energy, described what was happening on the island as “an energy insurrection.” Ordinary Puerto Ricans, he said, had woken up to the fact that when it came to electricity, they would have to look for alternatives.

This is part of a real solution. But that is not the direction that Puerto Rico is going. Instead the US government is planning on financing the privatization of PREPA through the creation of the “Puerto Rico Energy Transformation Administration (PRETA) that would provide guarantees (with US tax payer's money) for private energy corporations to rebuild the Puerto Rican grid. According to Debt Wire (https://www.debtwire.com/info/prepa-federalization-draft-bill-floating-congress)

Still in rough draft form, a bill tentatively titled the “Puerto Rico Energy Stabilization and Hurricane Resiliency Act of 2018” delineates specific steps to have the federal government—via the DOE—take over PREPA, impose a temporary administrator to supersede Puerto Rico’s Energy Commission ratemaking power, establish a corporation to issue restructuring bonds, and create special investment assurance accounts as part of the utility’s ongoing privatization process.

Here on Kauai the failure of privately owned Kauai Electric took a different but similar turn.

Those with long memories know what happened when the privately owned Kauai Electric called it quits. We paid off the "stake holders" a couple hundred million dollars of borrowed money to create a the debt ridden Kauai Island Utility Cooperative (KIUC). We now pay about the highest rates in the country.

Like Puerto Rico, Kauai is a stand alone grid on an isolated island. What energy it produces is all the energy it will have available. To its credit, KIUC has aggressively been adding solar voltaic power generation capacity. But it has not encouraged Solar PV stand alone systems.

Instead it encourages "co-generation"... the placement of PV systems on individual homes to supplement KIUC power generation. Co-gen certainly can reduce KIUC's high price for grid power, but it is, by my observation,  no real incentive to reduce power consumption.

Co-gen also means some resilience capability if the grid goes down because of a natural disaster, electro-magnetic pulse (EMP) or other disaster.

But KIUC suffers from the same vulnerability that Puerto Rico faced when Maria struck. All the power distribution is provided by poles and large hurricane can knock those poles down like a house of cards. That happened on Kauai with hurricane Iniki in 1992. But instead of burying the power distribution lines (as is done in most modern community planning) Kauai Electric simply re-erected the old creosote soaked wooden power poles.

Stand alone solar power systems have several advantages if they are not backed up by a electric grid or fossil fuel powered generator.

• They absolutely limit the consumption of power to the amount of energy collected from the sun.
• They require customer awareness of usage and some maintenance encouraging greater self reliance.
• They reduce overall power consumption by high energy appliances like microwave ovens or air compressors.
• They are resilient in that only the minority of systems that are hit directly by a disaster are damaged.
• They wean us from living outside the limitations of energy not supplied by nature where you live.  

What we found was that having multiple independent stand alone PV systems is a real advantage. We stumbled into that situation by slowing adding systems over time. We started with a single panel and added increasingly bigger systems over almost a decade as we gained experience and knowledge.

All our systems use an array of one of two battery types. One type are high capacity 12volt 110amp-hour lead acid deep cycle batteries available on Kauai. The other type are 6v 405 amp-hour AGM (absorbant glass mat) batteries.

There are two AGM systems.

One is attached to our circuit breaker panel-box. This is where KIUC used to hook up. We had KIUC come and take off the meter and wiring to our house. This systems powers all the switches and outlets built into the house.

The second AGM system is attached to a power inverter providing energy for our new refrigerator and freezer. See (http://islandbreath.blogspot.com/2018/09/freezers-up-and-running.html).

The five other systems are smaller for specific tasks using smaller power inverters.

• One provides counter lighting and strip outlets for our kitchen as well as our guest bathroom.
• A second one provides lighting and a power strip to our master bedroom and its bathroom.
• A third one provides lighting and a power strip  (for tool battery charging) in shop/utility room.
• A fourth provides power for and office computer, wifi system and small appliance batteries.
• A fifth provides power to a stand-alone shack that serves as a guest house. 

This overlapping redundancy has proved to be valuable. Any one system can go down and we can work around the problem by switching plugs in outlets and/or swapping around compatible batteries.

Redundancy is good. We had a neighbor who went with KIUC co-gen. After about a year the single co-gen system inverter failed and her solar panels were providing nothing to reduce her energy bill. The installer claimed it was out of warranty and not their problem. It took over year to get the system up and working agian.

Looking to the future my advice, as usual, is learn to and act to:

• Grow your own food
• Collect your own water
• Produce your own energy
• Make and repair what you can.

The alternative is sitting around a fire with pointy sticks.

Freezers up and running

SUBHEAD: Our two new freezers (one converted to fridge) are running off solar and working as expected.

By Juan Wilson on 1 September 2018 for Island Breath -
(http://islandbreath.blogspot.com/2018/09/freezers-up-and-running.html)


Image above: Top opening 10.6cuft General Electric chest freezer model number FCM11PHBWW with three movable bins and built in light costing about $449 on our lanai.

We are off the electric grid (KIUC) and run our homestead entirely on photovoltaic power spread across seven dedicated systems. One is dedicated to just our freezer and refrigerator. For quite some time we have suffered with inadequate energy to run our 16cuft refrigerator.

The small chest 4.5cuft freezer has been no trouble, but the refrigerator has been a real hassle - especially in the darker winter months.  Add to that our eight 405 amp-hour 6volt batteries dedicated to cooling food are going into their fifth year.

We realized that the chest design of the freezer was a great advantage over the front loading fridge. Every time the fridge door is opened all the cold air slides out. If you are making a complicated meal it's tough keeping that fridge cool.

We replaced a front loading 16cuft refrigerator and a 4.5cuft freezer with two 10.6cuft freezers. One of the freezer we put on our covered lanai just outside of our kitchen/dining room. It is more out of the weather than our previous freezer location that was in our carport (shop/laundry room).

The other freezer was placed where our upright front loading refrigerator used to be. Note we never got the use of the jalousie window with the old fridge there.


Image above: Top opening 10.6cuft General Electric chest freezer converted to a fridge with the use of a thermostat to shut it off when the temperature approaches 32ºF

Of course, there are advantages in organizing (or the lack there of) when using an upright refrigerator. Fortunately the freezer we found to use as a fridge had two features that helped a lot.

One - it comes with three plastic coated metal wire bins that slide on a ledge just under the top .
Two - it has a light on the underside of the top opening door that turns on when you lift the top.




Image above:Above the thermostat and monitor for the converted freezer to make it a refrigerator.

Left is the control for the thermostat that has a sensor on a long copper tube. It can be adjusted down to 20ºf. We are using it set to 32ºf. On the right is the source of electricity. The tan extension cord runs down and through the wall to the covered porch outside our front door. That is where our 110volt inverter sits just over the battery array under the porch.

Plugged into the cord is a power monitor that shows the refrigerator is pulling 88 watts while it is cooling. Plugged into the monitor is the thermostat and plugged into the thermostat is the fridge.

We bought the Johnson Controls Freezer Temperature Controller from Amazon.  This thermostat converts the freezer to a fridge.

So far so good. We are watching and adjusting how we load and use these units. 

See also:
Ea O Ka Aina: The Forthcoming freezers 8/25/18
Ea O Ka Aina: Convert Freezer to Fridge 7/21/18
Ea O Ka Aina: Guilt Free Cold Beer 3/7/10





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The Forthcoming Freezers

SUBHEAD: Our ability to refrigerate and freeze food reliably off-grid requires converting to chest units only.

By Juan Wilson on 25 August 2018 for Island Breath -
(http://islandbreath.blogspot.com/2018/08/the-forthcoming-freezers.html)


Image above: Our current 16cuft fridge next the front door. The new 10.6 cuft freezer will turned be transformed into a refrigerator (set at 33 fahrenheit with a GE thermostatic switch. Note the microwave on top of the fridge is used only for storing open bags of chips and crackers. It's not plugged in because it will trip the PV inverter if turned on. Photo by Juan Wilson.

[IB Publisher's note: We are facing a problem with our 16 cubic foot refrigerator - it's not efficient enough to run on the the batteries charged by our solar PV system. We are looking to convert a 10 cubic foot freezer into a refrigeration unit and live with the inconvenience of organizing and searching the bin for its contents. We'll let you know how that goes.]

We have been off the power grid long enough to have learned a few things. Perhaps the toughest lesson was finding it really difficult to keep refrigeration going 24/7/365. A lot of things that require power can be episodic. That includes wi-fi internet access, electric lighting, and entertainment systems.

We have moved up from 8 120 amp-hour 12 volt deep cycle marine batteries to 8 405 amp-hour 6 volt AGM batteries. That's the same size array of batteries that run all out power outlets and switched lighting. After struggling through several seasons of darker than summer days we realized we could not run conventional refrigeration. That being an upright unit with a front door. The unit simply loses most of its cold air every time you open the door merely to see what's inside.

We had to go to a chest refrigerator. We also needed a bigger freezer to store all the food we process and store (like a year's worth of macadamia nuts, and packages of pre-cooked and seasoned cassava, taro and breadfruit.

We read about this solution in Kendra's post "Convert Freezer into Fridge" (http://islandbreath.blogspot.com/2018/07/convert-freezer-into-fridge.html), from New Life on a Homestead on 7/21/18.

Since July we have taken steps to rid ourselves of and upright refrigerator and expand our capacity to freeze for for long term storage.  The plan included purchasing two 10.6 cubic foot freezers. One would be converted to a refrigerator using the technique in the referenced article linked above.  The other would be a straight up freezer.

We purchased the freezers from Home Depot.  They are General Electric model FCM11PH Chest Freezer (garage ready) with an Energy Guide estimate of $26 estimated yearly energy cost. Of course that $26 is totally unrelated to the actual energy cost from Kauai's KIUC power company opr the fact that we will be running them off batteries charged from solar panels.

What the $26 does indicate is that this freezer is in a sweet spot being less energy costly than any of the smaller freezers we considered. Of course, we'll see what find out the actual consumption only when we are up and running.

We were notified yesterday that the two freezers had arrived on Kauai and would be delivered on August 31. So we are beginning now to execute changes we'll need to accommodate the switch over. Will have Home Depot remove the 4 cubic foot freezer in our garage the 16 cubic foot refrigerator.

One of the new freezers (the one we'll user as a fridge) will be placed in our kitchen/dining area where the old fridge was. It will be wider, lower and a bit less deep and requires some storage changes - like no storage on top of the fridge like now.

The other freezer will be on our lanai, just outside the the kitchen/dining area. That means no more trecking down and outside to get to the garage and our current freezer.

More on the installation and use of these units as we go.

On re-reading the specs again I realized that these new freezers have built in lighting. That is great, in that I won't have to install additional lighting on each unit that would be foot operated (or something).

More on this effort when the freezers arrive.


Image above: Our current 4 cu ft freezer is closer to the weather than the lanai location we intend for its replacement. Note rust at front right corner closest to the outside of our open "garage" (washroom, shop, storeroom, etc). Photo by Juan Wilson.

Ditch the Batteries

SUBHEAD: Compressed air has longer life expectancy, technical simplicity, lower cost and lower maintenance.

By Kris De Decker on 9 June 2018 for Low Tech Magazine-
(http://www.lowtechmagazine.com/2018/05/ditch-the-batteries-off-the-grid-compressed-air-energy-storage.html)


Image above: Commercial large compressed air storage tanks. From original article.

Going off-grid? Think twice before you invest in a battery system. Compressed air energy storage is the sustainable and resilient alternative to batteries, with much longer life expectancy, lower life cycle costs, technical simplicity, and low maintenance.

Designing a compressed air energy storage system that combines high efficiency with small storage size is not self-explanatory, but a growing number of researchers show that it can be done.

Compressed Air Energy Storage (CAES) is usually regarded as a form of large-scale energy storage, comparable to a pumped hydropower plant. Such a CAES plant compresses air and stores it in an underground cavern, recovering the energy by expanding (or decompressing) the air through a turbine, which runs a generator.

Unfortunately, large-scale CAES plants are very energy inefficient. Compressing and decompressing air introduces energy losses, resulting in an electric-to-electric efficiency of only 40-52%, compared to 70-85% for pumped hydropower plants, and 70-90% for chemical batteries. The low efficiency is mainly since air heats up during compression.

This waste heat, which holds a large share of the energy input, is dumped into the atmosphere. A related problem is that air cools down when it is decompressed, lowering electricity production and possibly freezing the water vapour in the air.

To avoid this, large-scale CAES plants heat the air prior to expansion using natural gas fuel, which further deteriorates the system efficiency and makes renewable energy storage dependent on fossil fuels.

Why Small-scale CAES?
In the previous article, we outlined several ideas – inspired by historical systems – that could improve the efficiency of large-scale CAES plants.

In this article, we focus on the small but growing number of engineers and researchers who think that the future is not in large-scale compressed air energy storage, but rather in small-scale or micro systems, using man-made, aboveground storage vessels instead of underground reservoirs. Such systems could be off-the-grid or grid-connected, either operating by themselves or alongside a battery system.

The main reason to investigate decentralised compressed air energy storage is the simple fact that such a system could be installed anywhere, just like chemical batteries.

Large-scale CAES, on the other hand, is dependent on a suitable underground geology. Although there are more potential sites for large-scale CAES plants than for large-scale pumped hydropower plants, finding appropriate storage caverns is not as easy as was previously assumed. [1-2] [3]

Compared to chemical batteries, micro-CAES systems have some interesting advantages. Most importantly, a distributed network of compressed air energy storage systems would be much more sustainable and environmentally friendly. Over their lifetimes, chemical batteries store only two to ten times the energy needed to manufacture them. [4] Small-scale CAES systems do much better than that, mainly because of their much longer lifespan.

Compared to chemical batteries, a distributed network of compressed air energy storage systems would be much more sustainable and environmentally friendly

Furthermore, they do not require rare or toxic materials, and the hardware is easily recyclable. In addition, decentralised compressed air energy storage doesn’t need high-tech production lines and can be manufactured, installed and maintained by local business, unlike an energy storage system based on chemical batteries.

Finally, micro-CAES has no self-discharge, is tolerant of a wider range of environments, and promises to be cheaper than chemical batteries. [5]

Although the initial investment cost is estimated to be higher than that of a battery system (around $10,000 for a typical residential set-up), and although above-ground storage increases the costs in comparison to underground storage (the storage vessel is good for roughly half of the investment cost), a compressed air energy storage system offers an almost infinite number of charge and discharge cycles. Batteries, on the other hand, need to be replaced every few years, which makes them more expensive in the long run. [5,6]

Challenge: Limiting Storage Size
However, decentralised CAES also faces important challenges. The first is the system efficiency, which is a problem in large- and small-scale systems alike, and the second is the size of the storage vessel, which is especially problematic for small-scale CAES systems.

Both issues make small-scale CAES systems unpractical. Sufficient space for a large storage vessel is not always available, while a low storage efficiency requires a larger solar PV or wind power plant to make up for that loss, raising the costs and lowering the sustainability of the system.

To make matters worse, system efficiency and storage size are inversely related: improving one factor is often at the expense of the other.

Increasing the air pressure minimizes the storage size but decreases the system efficiency, while using a lower pressure makes the system more energy efficient but results in a larger storage size. Some examples help illustrate the problem.

A simulation for a stand-alone CAES aimed at unpowered rural areas, and which is connected to a solar PV system and used for lighting only, operates at a relatively low air pressure of 8 bar and obtains a round-trip efficiency of 60% -- comparable to the efficiency of lead-acid batteries. [7]

However, to store 360 Wh of potential electrical energy, the system requires a storage reservoir of 18 m3, the size of a small room measuring 3x3x2 meters. The authors note that “although the tank size appears very large, it still makes sense for applications in rural areas”.

System efficiency and storage size are inversely related: improving one factor is often at the expense of the other.

Such a system may indeed be beneficial in this context, especially because it has a much longer lifespan than chemical batteries. However, a similar configuration in an urban context with high energy use is obviously problematic.

In another study, it was calculated that it would take a 65 cubic meter air storage tank to store 3 kila-watt hours of energy. This corresponds to a 13 meter long pressure vessel with a diameter of 2.5 meters, shown below. [8]


Image above: Compressed air storage tank 6 feet high by 45 feet long could store 3 kWh of energy. From original article.

Furthermore, average household electricity use per day in industrialised countries is much higher still. For example, in the UK it’s slightly below 13 kWh per day, in the US and Canada it’s more than 30 kWh. In the latter case, ten such air pressure tanks would be required to store one day of electricity use.

Small-scale CAES systems with high pressures give the opposite results. For example, a configuration modeled for a typical household electrical use in Europe (6,400 kWh per year) operates at a pressure of 200 bar (almost 4 times higher than the pressure in large-scale CAES plants) and achieves a storage volume of only 0.55 m3, which is comparable to batteries. However, the electric-to-electric efficiency of this set-up is only 11-17%, depending on the size of the solar PV system. [9]

Two Strategies to Make Micro CAES work
These examples seem to suggest that compressed air energy storage makes no sense as a small-scale energy storage system, even with a reduction in energy demand. However, perhaps surprisingly to many, this is not the case.

Small-scale CAES systems cannot follow the same approach as large-scale CAES systems, which increase storage capacity and overall efficiency by using multi-stage compression with intercooling and multi-stage expansion with reheating.

This method involves additional components and increases the complexity and cost, which is impractical for small-scale systems.

The same goes for “adiabatic” processes (AA-CAES), which aim to use the heat of compression to reheat the expanding air, and which are the main research focus for large-scale CAES. For a micro-CAES system, it’s very important to simplify the structure as much as possible. [5,10]

This leaves us with two low-tech strategies that can be followed to achieve similar storage capacity and energy efficiency as lead-acid batteries. First, we can design low pressure systems which minimize the temperature differences during compression and expansion. Second, we can design high pressure systems in which the heat and cold from compression and expansion are used for household applications.
Small-scale, High Pressure
Small-scale compressed air energy storage systems with high air pressures turn the inefficiency of compression and expansion into an advantage.

While large-scale AA-CAES aims to recover the heat of compression with the aim of maximizing electricity production, these small-scale systems take advantage of the temperature differences to allow trigeneration of electrical, heating and cooling power.

The dissipated heat of compression is used for residential heating and hot water production, while the cold expanding air is used for space cooling and refrigeration. Chemical batteries can’t do this.

Small-scale, high pressure systems use the dissipated heat of compression for residential heating and hot water production, while the cold expanding air is used for space cooling and refrigeration.

In these systems, the electric-to-electric efficiency is very low. However, there are now several efficiencies to define, because the system also supplies heat and cold. [10,11]

Furthermore, this approach can make several electrical appliances unnecessary, such as the refrigerator, the air-conditioning, and the electric boiler for space and water heating. Since the use of these appliances is often responsible for roughly half of the electricity use in an average household, a small-scale CAES system with high pressure has lower electricity demand overall.

High pressure systems easily solve the issue of storage size. As we have seen, a higher air pressure can greatly reduce the size of a compressed air storage vessel, but only at the expense of increased waste heat.

In a small-scale system that takes advantage of temperature differences to provide heating and cooling, this is advantageous.

Therefore, high pressure systems are ideal for small-scale residential buildings, where storage space is limited and where there is a large demand for heat and cold as well as electricity.

The only disadvantages are that high pressure systems require stronger and more expensive storage tanks, and that extra space is required for heat exchangers.


Image above: Experimental set-up of a micro CAES system. From original article, Source [30].

Several research groups have designed, modeled and built small-scale combined heat-and-power CAES units which provide heating and cooling as well as electricity.

The high pressure system with a storage volume of only 0.55 m3 that we mentioned earlier, is an example of this type of system. [9]

As noted, its electrical efficiency is only 11-17%, but the system also produces sufficient heat to produce 270 litres of hot water per day. If this thermal source of energy is also taken into account, the “exergetic” efficiency of the whole system is close to 70%.

Similar "exergy" efficiencies can be found in other studies, with systems operating at pressures between 50 and 200 bar. [11-21]

Heat and cold from compression and expansion can be distributed to heating or cooling devices by means of water or air. The setup of an air cycle heating and cooling system is very similar to a CAES system, except for the storage vessel.

Air cycle heating and cooling has many advantages, including high reliability, ease of maintenance, and the use of a natural refrigerant, which is environmentally benign. [11]

Small-scale, Low Pressure
The second strategy to achieve higher efficiencies and lower storage volumes is exactly the opposite from the first.

Instead of compressing air to a high pressure and taking advantage of the heat and cold from compression and expansion, a second class of small-scale CAES systems is based on low pressures and “near-isothermal” compression and expansion.

Below air pressures of roughly 10 bar, the compression and expansion of air exhibit insignificant temperature changes (“near-isothermal”), and the efficiency of the energy storage system can be close to 100%. There is no waste heat and consequently there is no need to reheat the air upon expansion.

Isothermal compression requires the least amount of energy to compress a given amount of air to a given pressure. However, reaching an isothermal process is far from reality. To start with, it only works with small and/or slowly cycling compressors and expanders. Unfortunately, typical industrial compressors are not made for maximum efficiency but for maximum power and thus work under fast-cycling, non-isothermal conditions. The same goes for most industrial expanders. [22-24]

Below air pressures of 10 bar, compression and expansion of air exhibit insignificant temperature changes and the efficiency can be close to 100%.

The use of industrial compressors and expanders explains in large part why the low pressure CAES systems mentioned at the beginning of this article have such large storage vessels. Both systems are based on devices which are operated outside of their optimal or rated conditions. [25]

Because inefficiencies multiply during energy conversions, even relatively small differences in the efficiency of compressors and expanders can have large effects. For example, a variation in device efficiency from 60% to 80% results in a system efficiency from 36% to 64%, respectively.
New Types of Compressors and Expanders
Because the performance of a compressor and an expander significantly impact the overall efficiency of a small-scale CAES system, several researchers have built their own compressors and expanders, which are especially aimed at energy storage.

For example, one team designed, built and examined a single-stage, low power isothermal compressor that uses a liquid piston. [22]

It operates at a very low compression rate (between 10-60 rpm), which correspond to the output of solar PV panels, and limits temperature fluctuation during compression and expansion to 2 degrees Celsius.

The low-cost device has minimum moving parts and obtains efficiencies of 60-70% at 3 to 7 bar pressure. [22] This is a very high efficiency for such a simple device, considering that a sophisticated three-stage centrifugal compressor, used in large-scale CAES systems or in industrial settings, is roughly 70% efficient.

Furthermore, the researchers state that the efficiency is limited by the off-the-shelf motor that they use to power their compressor. Indeed, another research team achieved 83% efficiency. [26]


Image above: A cutaway view of a modern, quiet, oil free scroll format air compressor. From (http://www.fusheng.com/FSAP/F_ProductInfo?ProductId=Prod_1-11-0&n=GW%20Series%20Oil-free%20Scroll%20Air%20Compressor&r_reg=en-us&rndt=w1tupMXK).

Another novelty is the use of scroll compressors, which are the types of compressors that are now used in refrigerators, air-conditioning systems, and heat pumps. Both fluid piston and scroll compressors have a high area-to-volume ratio, which minimizes heat production, and can easily handle two-phase flow, which means that they can also be used as expanders.

They are also lighter and less noisy than typical reciprocating compressors. [24]
 
Varying Air Pressure
Although compressors and expanders are the most important determinants of system efficiency in small-scale CAES systems, they are not the only ones.

For example, in every compressed air energy storage system, additional efficiency loss is caused by the fact that during expansion the storage reservoir is depleted and therefore the pressure drops. Meanwhile, the input pressure for the expander is required to vary only in a minimal range to assure high efficiency.

This is usually solved in two ways, although neither is really satisfactory. First, air can be stored in a tank with surplus pressure, after which it is throttled down to the required expander input pressure. \

However, this method – which is used in large-scale CAES – requires additional energy use and thus introduces inefficiency.

Second, the expander can operate at variable conditions, but in this case efficiency will drop along with the pressure while the storage is emptied.

During expansion the storage reservoir is depleted and therefore the pressure drops.

With these problems in mind, a team of researchers combined a small-scale CAES with a small-scale pumped hydropower plant, resulting in a system that maintains a steady pressure during the complete discharge of the storage reservoir.

It consists of two compressed air tanks that are connected by a pipe attached to their lower portions: each of these have separate spaces for air (below) and water storage (above).

The configuration maintains a head of water by means of a pump, which consumes 15% of the generated power. However, in spite of this extra energy use, the researchers managed to increase both the efficiency and the energy density of the system. [11]

Off-the-Grid Power Storage
To give an idea of what a combination of the right components can achieve, let’s have a look at a last research project. [27] It concerns a system that is based on a highly efficient, custom-made compressor/expander, which is directly coupled to a DC motor/generator.

Apart from its efficient components, this CAES project also introduces an innovative system configuration. It doesn’t use one large air storage tank, but several smaller ones, which are interconnected and computer-controlled.

The setup consists of the compression/expansion unit coupled to three small (7L) cylinders, previously used as air extinguishers, and operates at low pressure (max 5 bar). The storage vessels are connected via PVC pipework and brass fittings.

To control the air-flow, three computer-controlled air valves are installed at the inlet of each cylinder. The system can be extended by adding more pressure vessels. [27]


Image above: A modular system of multiple compressor tanks has multiple advantages. From original article.

A modular configuration results in a higher system efficiency and energy density for mainly two reasons.

First, it helps more effective heat transfer to take place, because every air tank acts as an additional heat exchanger.
 
Second, it allows better control over the discharge rate of the storage reservoir.

The cylinders can be discharged either in unison to satisfy a demand for high power density (more power at the cost of a shorter discharge time), or they can be discharged sequentially to satisfy a demand for high energy density (longer discharge time at the cost of maximum power).

By discharging modular storage cylinders sequentially, the discharge time can be greatly increased, making the system comparable to lead-acid batteries in terms of energy density.

By discharging the cylinders sequentially, the discharge time can be greatly increased, making the system comparable to lead-acid batteries in terms of energy density. Based on their experimental set-up, the researchers calculated the efficiencies for different starting pressures and numbers of cylinders.

They found that 57 interconnected cylinders of 10 litre each, operating at 5 bar, could fulfill the job of four 24V batteries for 20 consecutive hours, all while having a surprisingly small footprint of just 0.6 m3.

Interestingly, the storage capacity is 410 Wh, which is comparable to the 360 Wh rural system noted earlier, which requires an 18 m3 storage vessel – that’s thirty times larger than the modular storage system.

The electric-to-electric efficiency for the 3-cylinder set-up reached a peak of 85% at 3 bar pressure, while the estimated efficiency for the 57-cylinder set-up is 75%.

These are values comparable to lithium-ion batteries, but adding more storage vessels or operating at higher pressures introduces larger losses due to compression, heat, friction and fittings. [27-29]

Nevertheless, when I e-mailed Abdul Alami, the main author of the study, thinking that the results sounded too good to be true, he told me that the figures were actually overly conservative: “We stuck to low pressures to achieve near-isothermal compression and to ensure safe operation.

Operating at pressures higher than 10 bar would create serious thermal losses, but a pressure of 7-8 bar may be beneficial in terms of energy and power density, though maybe not in terms of efficiency.”

Build it Yourself?

In conclusion, small-scale compressed air energy storage could be a promising alternative to batteries, but the research is still in its early stages – the first study on small-scale CAES was published in 2010 – and new ideas will continue to shed light on how best to develop the technology.

At the moment, there are no commercial products available, and setting up your own system can be quite intimidating if you are new to pneumatics.

Simply getting hold of the right components and fittings is a headache, as these come in a bewildering variety and are only sold to industries.

However, if you’re patient and not too unhandy, and if you are determined to use a more sustainable energy storage system, it is perfectly possible to build your own CAES system. As the examples in this article have shown, it’s just a bit harder to build a good one.

There's more ideas for small-scale CAES systems in the previous article: History and Future of the Compressed Air Economy.

References & Notes
[1] Luo, Xing, et al. "Overview of current development in electrical energy storage technologies and the application potential in power system operation." Applied Energy 137 (2015): 511-536. https://www.sciencedirect.com/science/article/pii/S0306261914010290

[2] Laijun, C. H. E. N., et al. "Review and prospect of compressed air energy storage system." Journal of Modern Power Systems and Clean Energy 4.4 (2016): 529-541. https://link.springer.com/article/10.1007/s40565-016-0240-5

[3] There is increasing competition for potential CAES geologic units, as many are also well suited to the storage of natural gas or sequestered carbon. Furthermore, cavern storage imposes harsh requirements on the geographical conditions. For example, the originally planned Iowa CAES project in the US was terminated due to its porous sandstone condition. [2]

[4] Barnhart, Charles J., and Sally M. Benson. "On the importance of reducing the energetic and material demands of electrical energy storage." Energy & Environmental Science 6.4 (2013): 1083-1092. https://gcep.stanford.edu/pdfs/EES_reducingdemandsonenergystorage.pdf

[5] Petrov, Miroslav P., Reza Arghandeh, and Robert Broadwater. "Concept and application of distributed compressed air energy storage systems integrated in utility networks." ASME 2013 Power Conference. American Society of Mechanical Engineers, 2013. http://eddism.com/wp-content/uploads/2014/10/Paper-EDD-Concept-and-Application-of-Distributed-Compressed-Air-Energy-Storage-Systems-Integrated-in-Utility-Networks-July-2013.pdf

[6] Tallini, Alessandro, Andrea Vallati, and Luca Cedola. "Applications of micro-CAES systems: energy and economic analysis." Energy Procedia 82 (2015): 797-804.

[7] Setiawan, A., et al. "Sizing compressed-air energy storage tanks for solar home systems." Computational Intelligence and Virtual Environments for Measurement Systems and Applications (CIVEMSA), 2015 IEEE International Conference on. IEEE, 2015. https://www.researchgate.net/profile/Ardyono_Priyadi/publication/274898992_Sizing_Compressed-Air_Energy_Storage_Tanks_for_Solar_Home_Systems/links/5670e2c408ae2b1f87acf927.pdf

[8] Herriman, Kayne. "Small compressed air energy storage systems." (2013). https://eprints.usq.edu.au/24651/1/Herriman_2013.pdf

[9] Manfrida, Giampaolo, and Riccardo Secchi. "Performance prediction of a small-size adiabatic compressed air energy storage system." International Journal of Thermodynamics 18.2 (2015): 111-119. http://dergipark.ulakbim.gov.tr/eoguijt/article/download/5000071710/5000113411

[10] Kim, Y. M., and Daniel Favrat. "Energy and exergy analysis of a micro-compressed air energy storage and air cycle heating and cooling system." Energy 35.1 (2010): 213-220.

[11] Kim, Young Min. "Novel concepts of compressed air energy storage and thermo-electric energy storage." (2012). https://infoscience.epfl.ch/record/181540/files/EPFL_TH5525.pdf

[12] Inder, Shane D., and Mehrdad Khamooshi. "Energy Efficiency Analysis of Discharge Modes of an Adiabatic Compressed Air Energy Storage System." World Academy of Science, Engineering and Technology, International Journal of Electrical, Computer, Energetic, Electronic and Communication Engineering 11.12 (2017): 1101-1109.

[13] Vollaro, Roberto De Lieto, et al. "Energy and thermodynamical study of a small innovative compressed air energy storage system (micro-CAES)." Energy Procedia 82 (2015): 645-651.

[14] Li, Yongliang, et al. "A trigeneration system based on compressed air and thermal energy storage." Applied Energy 99 (2012): 316-323. https://www.sciencedirect.com/science/article/pii/S0306261912003479

[15] Facci, Andrea L., et al. "Trigenerative micro compressed air energy storage: Concept and thermodynamic assessment." Applied energy 158 (2015): 243-254. https://www.sciencedirect.com/science/article/pii/S0306261915009526

[16] Mohammadi, Amin, et al. "Exergy analysis of a Combined Cooling, Heating and Power system integrated with wind turbine and compressed air energy storage system." Energy Conversion and Management 131 (2017): 69-78. https://www.sciencedirect.com/science/article/pii/S0306261915009526

[17] Yao, Erren, et al. "Thermo-economic optimization of a combined cooling, heating and power system based on small-scale compressed air energy storage." Energy Conversion and Management 118 (2016): 377-386. https://www.sciencedirect.com/science/article/pii/S0196890416302229

[18] Liu, Jin-Long, and Jian-Hua Wang. "Thermodynamic analysis of a novel tri-generation system based on compressed air energy storage and pneumatic motor." Energy 91 (2015): 420-429. https://www.sciencedirect.com/science/article/pii/S0360544215011317

[19] Lv, Song, et al. "Modelling and analysis of a novel compressed air energy storage system for trigeneration based on electrical energy peak load shifting." Energy Conversion and Management 135 (2017): 394-401. https://www.sciencedirect.com/science/article/pii/S0196890416311839

[20] Besharat, M. O. H. S. E. N., SANDRA C. Martins, and HELENA M. Ramos. "Evaluation of Energy Recovery in Compressed Air Energy Storage (CAES) Systems." 3rd IAHR Europe Congress. Book of Proceedings, Portugal. 2014. https://www.researchgate.net/profile/Mohsen_Besharat2/publication/270896130_Evaluation_of_Energy_Recovery_in_Compressed_Air_Energy_Storage_CAES_Systems/links/58a1fce0a6fdccf5e97109b2/Evaluation-of-Energy-Recovery-in-Compressed-Air-Energy-Storage-CAES-Systems.pdf

[21] Minutillo, M., A. Lubrano Lavadera, and E. Jannelli. "Assessment of design and operating parameters for a small compressed air energy storage system integrated with a stand-alone renewable power plant." Journal of Energy Storage 4 (2015): 135-144. https://www.sciencedirect.com/science/article/pii/S2352152X15300207

[22] Villela, Dominique, et al. "Compressed-air energy storage systems for stand-alone off-grid photovoltaic modules." Photovoltaic Specialists Conference (PVSC), 2010 35th IEEE. IEEE, 2010. https://pdfs.semanticscholar.org/9f1d/4273f8deb4a0a18c86eb4056e2fd378f8f3f.pdf

[23] Paloheimo, H., and M. Omidiora. "A feasibility study on Compressed Air Energy Storage system for portable electrical and electronic devices." Clean Electrical Power, 2009 International Conference on. IEEE, 2009. https://www.researchgate.net/profile/Michael_Omidiora/publication/224581292_A_Feasibility_Study_on_Compressed_Air_Energy_Storage_System_for_Portable_Electrical_and_Electronic_Devices/links/5640d5d308aebaaea1f6ad44.pdf 

[24] Prinsen, Thomas H. Design and analysis of a solar-powered compressed air energy storage system. Naval Postgraduate School Monterey United States, 2016. https://scholar.google.com/scholar?cluster=5783353621699682542&hl=nl&as_sdt=2005&sciodt=0,5

[25] The small-scale system aimed at urban environments, which has a storage reservoir of 18 metres long, is based on a compressor that “had been in service for 30 years on building sites to run various air tools and had little maintenance done”. [8] This is detrimental to system efficiency, because a compressor that is not maintained well easily wastes as much as 30% of its potential output through air leaks, increased friction, or dirty air filters. This small-scale system also used a highly inefficient expander. All together, this explains why it combines a very large storage volume with a very low electric-to-electric efficiency (less than 5%).

[26] Van de Ven, James D., and Perry Y. Li. "Liquid piston gas compression." Applied Energy 86.10 (2009): 2183-2191. https://experts.umn.edu/en/publications/liquid-piston-gas-compression

[27] Alami, Abdul Hai, et al. "Low pressure, modular compressed air energy storage (CAES) system for wind energy storage applications." Renewable Energy 106 (2017): 201-211.

[28] Alami, Abdul Hai. "Experimental assessment of compressed air energy storage (CAES) system and buoyancy work energy storage (BWES) as cellular wind energy storage options." Journal of Energy Storage 1 (2015): 38-43.

[29] Abdul Alami, e-mail conversation.

[30] Sun, Hao, Xing Luo, and Jihong Wang. "Feasibility study of a hybrid wind turbine system–Integration with compressed air energy storage." Applied Energy 137 (2015): 617 -628. https://www.sciencedirect.com/science/article/pii/S0306261914006680

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