Thursday, March 29, 2012

Combining renewable power for reliability

Right-wing pundits were crowing this past week that green energy (by which they mean solar and wind) is unreliable and too expensive, so we should abandon any government subsidies. But they rely on a combination of falsehood and selective facts. In reality, ALL electricity generation is subsidized, and reliability issues plague most electricity sources.
One constant tactic by the pundits is to blame all of Ontario's electricity cost increases on new solar or wind supply, although in reality wind makes up only 2% of our supply and solar inputs are still negligible. Up to this point, neither one of them has a significant impact on electric bills. The other thing they ignore is to treat any renewable energy subsidy in isolation, never mentioning (for example) the $367 million a year we pay in subsidies for coal power we're not using, or the billions of dollars we have paid, and continue to pay, in all kinds of subsidies for nuclear energy. And they never look at the huge impact on our economy from coal or other polluting energy sources in terms of health costs, lost productivity, and lower crop yields. If you actually look at renewables in the context of all our various electricity supply policies and costs, they are a comparable price.  Wind is already competitive with other sources on the open market, and solar soon will be.
What the pundits mean by “reliability” is actually dispatchable generation, electricity generated right when you need it, idle when you don’t. Yet the only major power source in Ontario which truly does this is natural gas plants. Run-of-river hydro (like Niagara Falls) is either gathering energy, or letting the water flow by. Coal power ramps up or down over a slower timeline; at best to match predicted hourly demand. Nuclear is always on, so they call it baseload power; you can’t turn it on and off as needed. Current demand often dips below base load supply, so we periodically must pay to dump excess nuclear power.
But there is more to reliability than dispatchability. Wind and solar are intermittent, but we know there will always be some windy days, and the sun will rise every day, and both of them are free. We don’t know gas costs of future years, so we can’t rely on gas-fired electricity to stay cheap. Nuclear plants also have reliability issues. Shut down by the big blackout of 2003, it took days (rather than the expected hours) to get them back up. Every time we take a nuke offline for maintenance or repair, it takes longer than expected, and vastly higher cost, to get it up and running again.
To better use solar and wind, we simply need storage capacity. One form of storage on the horizon is the batteries of electric or plug-in hybrid cars. Connecting to the grid when not on the road, they will allow storage of extra electricity when sun & wind are generous, to be drawn back at times of peak demand.
Yet even without batteries, renewable energy can be on-demand with the concept of the Combined Power Plant. This is where different renewable generation sources, like solar, wind, hydro and biomass plants, are linked in a single supply system. When wind and sun are abundant, hydro builds up reserves and biomass is idle. When they are not, hydro and biomass draw on their reserves as needed to make up the difference. Computers match them to minute-to-minute demand fluctuations. This combined system is just as reliable and powerful as a conventional large-scale power station, as was successfully demonstrated in Germany five years ago.
Although Ontario hasn’t enough dam-based hydro to do this on a large scale now, we could certainly pair our solar, wind, and biomass with hydro imported from Quebec and Manitoba, or possibly new dams of our own on James Bay, for a reliable, 100% renewable electricity supply.

A shorter version of this was published in my Root Issues column in the Barrie Examiner under the title "Combining renewable power a bright idea".
Erich Jacoby-Hawkins is a director of the Ontario School of Economic Science and Earthsharing Canada

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