Enabling Wind, Sun To Be Our Main Power Supplies
Quest for Storage -- "Holy Grail" of New Energy Economy -- Nears Goal
August 29, 2009
By Craig Severance
As the world meets this December to set plans to halt global warming, it is expected America and other industrial nations will commit to a daunting task: reduce CO2 emissions 80% by 2050. In just 40 years, a complete revolution in how we use and supply our power must happen, or the world will face catastrophic effects of runaway climate changes.
As a new power plant typically lasts 40-50 years, many scientists are now arguing we must simply stop building new power systems that use significant amounts of fossil fuels. They argue we must move to a high reliance on the wind and the sun for our electricity.
Abundant Power. The U.S. has enormous wind resources, capable of generating over 20% of U.S. electricity from wind by 2030, according to the U.S. Department of Energy.
The sunlight falling on our deserts, parking lots, and rooftops has even more power -- enough to supply 69% of U.S. electricity by 2050 according to published studies.
Other renewable power sources -- such as geothermal energy, municipal waste-to-energy, and biomass -- will also play a role, but they pale in size compared to the gargantuan resources of wind and sunlight.
How We Use Energy vs. How Nature Provides. Though nature provides all the energy we may need, there is a problem. We demand power literally "at the flick of a switch", not just when the wind is blowing or the sun is shining.
This basic fact about how we use power versus how nature supplies clean energy has caused many to discount the idea that wind or solar power can ever supply more than a small fraction of our electricity. Critics of renewable electricity call it "intermittent" and "unreliable". They say we can't "catch the wind", nor can we command the sun to always shine.
These critics see two possible choices for the future. We can develop more stable supplies of renewable energy by coupling wind and solar projects with storage. Failing that, they argue we should give up on renewables as a primary source of electricity, and instead build more nuclear power.
The flaw in the nuclear path, beyond its tremendous cost, long lead times, and imported fuel, is that nuclear is not actually "dispatchable" power. Nuclear plants are designed to run all the time at fairly steady output -- meaning nuclear power cannot provide the "peaking power" now provided by gas turbines. Thus, a nuclear path would still rely heavily on fossil fuel power plants to "ramp up" on a daily basis to provide the power needed during these daily swings.
A truly dispatchable system providing over 80% reductions in carbon emissions, therefore, must rely on some form of energy storage. The energy storage can allow us to fully utilize wind and sunlight as our main power sources -- supplying both "base load" power and dispatchable daily peaking power with energy from these inexhaustible supplies.
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