SUBHEAD: Renewable energy sources should come before electric grid infrastructure.  

By Henry Curtis on 9 January 2011 in Disappeared News -  

Image above: NYC barge sporting wind and solar energy power generation. From (http://www.earthzine.org/2010/04/19/ten-steps-to-a-smarter-grid).

 I had an opportunity to talk with a principal in Ku`oko`a a few weeks ago, and to receive a briefing yesterday. There are three issues that need elaboration to really understand the proposal: variable (intermittent) power, continuous (baseload) power, and centralization v. decentralization. I will discuss financing and leadership in a future blog. At a minimum, the Ku`oko`a Plan should move critical energy issues onto the front burner, and encourage community dialogue.  

Variable Power

Traditionally a utility argues that it is hard to add variable (intermittent) power to the grid. The sudden change in renewable energy inputs is hard for grid operators to manage. The utility seeks to maintain a constant supply of electricity. This can be done by adjusting the output of their fossil fuel generators though a process called ramping. It is easier for a utility to use natural gas generators (which we don’t have) to match the changes in intermittent renewable energy supply. It is harder with oil and diesel. Another approach is for the utility to reject (curtail) the renewable energy.

In responding the Big Wind EIS, Life of the Land suggested an alternative they called “beyond the box.” The utility should “seek to modify demand rather than supply,” by using successfully tested radio controls to turn on and off charging stations, battery storage equipment and related systems during periods of excess supply. Thus renewable energy would never need to be curtailed. Ku`oko`a advocates a similar approach. When there is too much supply of renewable energy the utility should make ammonia (NH3). Ammonia is used primarily for fertilizer. This could support both local farmers and be used for export.

Baseload Power

 Hawai`i has three choices for continuous (baseload) renewable energy power: biofuel, geothermal and ocean thermal. The utility favors biofuels, because unlike most generators in the U.S., Hawai`i generators use a liquid fuel, and could therefore also handle biofuel. Pacific Biodiesel has re-used waste grease and supported small local virgin crop to biodiesel operations. But on a grander scale, large commercial biofuel operations in the U.S. require huge subsidies and require turning a blind eye to side effects.

Here in Hawai`i, a State with only a few days supply of food, using virgin crop land for fuel presents several problems: an aging labor force, imported slave labor, water shortages, droughts, lack of biorefineries and high land prices, to mention a few. In addition, the only renewable fuel for airplanes is biofuel, whereas there are many choices for electricity. Therefore if one uses biofuels it should be used for transportation, and in particular, air transport. Ku`oko`a favors using geothermal as the baseload energy source.

Geothermal resources exists in at least two regions of the Big Island (Puna, West Side), two areas of Mau`i (Hana, Kihei coast) and one area of O`ahu. Ku`oko`a favors restricting the facilities to communities that accept such facilities. Life of the Land favors ocean thermal, which would have fewer impacts, not require an interisland grid, and be more applicable around the world. Ocean thermal energy conversion results in a minor reduction in ocean temperatures (it removes heat from the ocean and converts it into electricity). The thermal energy in the tropical ocean can supply 10,000 times all of the world’s energy needs. Life of the Land would only support geothermal if cultural practicioners felt it was okay.  

Centralization v. Decentralization

Hawaiian Electric favors building an undersea transmission line between O`ahu, Moloka`i and Lana`i. This line would extend at some point in the future, to Mau`i and then Hawai`i Island. It would allow one island to provide renewable energy to another island. Initially, wind energy would be shipped from Lana`i and Moloka`i to O`ahu. There are those who see interconnecting all of the island grids together as a way of making it more robust. A statewide grid could more easily absorb renewable energy. If there was a failure at some generator, then other generators could prevent a blackout. This statewide grid is favored by Ku`oko`a.

As an added bonus, they would institute a smart grid with smart meters at everyone’s home. These meters would measure energy use on a minute-to-minute basis. The smart grid would also provide free highspeed wi-fi service to every building in the State. Life of the Land favors greater decentralization. For the cost of the cable ($billions) a lot of renewable energy could come on-line.

Renewables should come before infrastructure, otherwise the infrastructure could use up the money and the renewable would never arrive. The State-HECO Agreement (2008) called for a utility reward (decoupling) and a utility loss (decreasing oil use and revenue in favor of renewables). The utility got decoupling and then fought renewables (feed-in tariffs). The increase of renewables should come first, before infrastructure changes and corporate bonuses.  

Responses to Comments asked by viewers of this article

 (1) I would like to know more about "decoupling" and how it changes incentives and affects costs. Decoupling is a rate scheme whereby the regulators determine what the utility should earn, and then as sales rise and fall, rates are automatically adjusted to maintain that planned rate of return. Thus the utility is indifferent to the replacement of its fossil fuel generators with renewables. This is quite different that being incentivized to want renewables. It also runs into problems because our State Legislature has defined certain fossil fuels to be “renewables.” (2) What is the power loss in the interisland cables? I have heard numbers up to 50%, which sounds high, but it cannot be insignificant. The power loss on a cable is low:
Power = volts x amps Power line loss (L) = k x A x A (a constant times the amps squared)
The reason we have high voltage lines is because they are low amp lines. A substation seeks to keep power constant while changing the amps and volts. On the Hawai`i grid in general power line loss is 4-7% (mostly on distribution lines). The longer undersea cable lines will use direct current instead of alternating current. These have less line loss. The reason for not using them on short lines is the cost of the AC-DC converter stations. (3) Europe is making extensive use of wave power generators.

Early examples in Scotland are still operating. Snake-like generators float off of Portugal. Are these suitable for Hawaii? Yes. Life of the Land favors the Oceanlinx model which has no lubricant and only one moving part which is above the waterline. A pilot project using this technology will be built off Maui. (4) Do we have the opportunity to pump water into reservoirs from either wind or solar generators and later run it through turbines when there is no wind or no sun, and what are the losses for something like that? The last pumped storage hydro built in the U.S. was 1984.

New ones are always in the works. They would not work well in Hawai`i because we would need to shift 2-4 hours of morning load into night load every day. It would be expensive, and a cloudy morning without wind may mean an evening blackout, unless we kept on hand all fossil fuel generators, kept them ready to generate electricity, which would also be expensive.

See also:
Ea O Ka Aina: HECO biofuel & privitizaation plans 1/9/11


No comments :

Post a Comment