Minnesota could affordably meet all of its electricity needs from wind and solar power, if those sources were coupled with the right mix of energy storage and efficiency improvements.
That’s the conclusion of a new report released today by the Institute for Energy and Environmental Research (IEER), a Maryland-based policy research group.
“It’s a first cut on how you would maintain the same level of reliability” — and cost — using only renewables, says Arjun Makhijani, IEER’s president and senior engineer.
IEER is a member of RE-AMP, which funds Midwest Energy News.
Under the 100-percent renewables scenario described in the report, Minnesota would be less vulnerable to swings in fossil fuel prices, it would have cleaner air and water, and it would only pay the equivalent of another 1-2 cents per kilowatt hour after energy efficiency gains are factored in.
Makhijani is author of Carbon-Free and Nuclear-Free: A Roadmap for U.S. Energy Policy, a 2007 book that argues the nation should move away from all forms of fossil fuel and nuclear power. The report on Minnesota renewables is among the first to take a closer look at the technical and economic feasibility of that goal on an individual state level.
The report examines Minnesota’s electricity needs for every hour of the year (based on 2007 data from Xcel Energy) and compares it to the potential wind and solar generation in the state during those same times. It finds that for most of the year, a bulked up commercial wind and rooftop solar sector could satisfy all of that demand, with a 12 percent cushion on top.
There are gaps, however, just like there are periods now, such as on hot summer days, when electricity demand exceeds utilities’ normal generating capacity, which forces them to fire up dirtier and expensive backup generators. Under an all-renewable scenario, there would be times in late summer when demand would exceed the state’s likely potential wind and solar power.
Just as with today’s peak load challenges, strategic investments in energy efficiency could eliminate many of these deficits between demand and generation. Makhijani calls the gaps that remain “relational peaks,” those crunch times when renewable generation falls below demand.
Under Makhijani’s vision, this is where energy storage comes in. Instead of turning to gas or oil peaking plants, utilities and grid operators could fill these gaps with a mix of storage technologies, including compressed air and pumped hydro energy storage. For its cost analysis, IEER used compressed air energy storage.
The report forecasts that transitioning from gas, coal and nuclear to wind, solar and storage would increase the price of electricity, but it says much of that increase could be masked by gains in energy efficiency. “If we do efficiency right, it can make a lot of things happen,” says Makhijani.
IEER says more study is needed, including closer looks at state-wide energy efficiency and storage potential, as well as regional, Midwest studies of demand dispatch, storage, “relational peaks,” and other grid-level issues.
Makhijani says moving toward a 100-percent renewable electricity system would be consistent with Minnesota’s existing goals, such as its legislative pledge to cut greenhouse emissions 80 percent by 2050. He says Minnesota should set a new goal of a 100 percent renewable energy standard, with realistic benchmarks and milestones.
The state’s public utility commission should also require utilities to include a 100-percent renewable model in their resource planning documents, he says.
“You’re not going to get there if you don’t put the idea on the table,” Makhijani says.
Photo by 4Neus via Creative Commons