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Wind and photovoltaic are suited to be 2 legs of clean-energy stool

Posted on Oct 4, 2011 in Honolulu Star-Advertiser, Photovoltaic, Wind

(Honolulu Star-Advertiser)  Sempra Generation has announced that it wants to build 300 megawatts of photovoltaic energy on Oahu, enough to rival Big Wind. Should we now run to that side of the boat? Is that the path we’re on? Is this the next step? Does anyone know where we’re going? Do you?

Increasingly, our energy initiative seems burdened by unpredictability. Naysayers argue endlessly on every possibility: wind, tax credits, the undersea cable, geothermal, biofuel, you name it. The naysayers are predictable, but how these arguments will wind up is unpredictable.

To find a path, the first thing we do is choose our primary renewables. Which ones should we develop, where and at what scale? We don’t want too few or too many. We need a thoughtful selection of proven sources.

The state has considered various sources over the last three years, and by now we should be able to choose well. Some are clearly out of the running: However inexpensive, nuclear is scary and coal is dirty. New technologies could make them more politically correct, but not yet.

Let’s start with two renewables that have traction, namely wind and PV. Wind is a proven technology that has been successfully installed all over the world. Hawaii has magnificent wind. It runs around the clock but produces only half as much at night. At scale it can light our cities.

PV is also proven technology and particularly promising in sun-rich Hawaii. We can put it unobtrusively on residential, business and government buildings. Before tax credits, PV is fairly expensive and doesn’t run at night, but we know it can generate utility-scale power.

That considered, wind and PV are certainly serious enough to serve as the first two legs of the clean-energy stool. Since they are nonfirm, they need the help of a third leg, a third source of power that is both firm and dispatchable and can fill in the gaps when production from the first two legs drops off. So what sources can we use to drive the third leg?

Despite the PUC’s decision against Aina Koa Pono last week, biofuel comes to mind first. Biofuel can be used in a combination of peaking plants, like the 100-megawatt fast-response peaking plant at Kapolei and the conventional but more efficient steam turbine plants. The combination can be used to balance the rough spots from the first and second legs.

These generating plants could be adapted to run on any number of liquid fuels, some fossil based and others agricultural or algae based, allowing each a role in the journey we need to take to convert to clean energy. The fuel for these plants could migrate from oil to natural gas from the mainland and biofuel from Hawaii, steadily weaning us off foreign oil.

The third leg could be batteries, but battery technology isn’t ready for that. Pumped /storage could serve the same purpose, but we may be short on the land or appetite for a dam. One possibility is in Molokai, where they’re building a 1.5 billion-gallon agricultural reservoir. This could be expanded to a pumped /storage facility big enough to service other islands, but as we know Molokai’s altruism might be limited.

Geothermal could be a great source for the third leg. It’s firm and could provide both dispatchable and base load power to back up the first and second legs. Puna could be expanded, and Mililani Trask’s IDG project could provide even more. We’ll need a second cable to transmit it west from Hawaii island, but so far cable technology isn’t ready to make the trip.

So let’s go with the flow and make wind and PV our primary sources, leaving other possibilities for later. Let’s develop Big Wind, enact the bill to facilitate development of the cable, continue the tax credits to expand PV and pass the biofuel production facility bill. Let’s use a smart selection of fuels to fire our existing generators and thus avoid the costs of new infrastructure.

Of course, there could be a mouse in the antipasto. There will be trial and error in building a brave new world of energy. If we find other steps would be useful later, we can do that then. As we learn more, we’ll get better at it and export our lessons to other places. But let’s not rely on the “precautionary principal” to wait until we’ve blown our chances.

We’re moving much too slowly. Let’s count our energy blessings, move beyond the gantlet of distraction and delay, and get these sources on line. Transformations are never easy or cheap. This one will be hard enough, so let’s not make it harder.