The Achilles Heal for wind energy is intermittency, or that’s what we have been told.
We need coal, nuclear and gas for reliable, baseload power, is the common refrain, but that’s a myth, according to the American Wind Energy Association (AWEA).
Instead, wind contributes to the stability of the grid, they say, and can be more reliable than conventional energy sources. Fluctuating supply and demand is fundamental to the grid – with or without wind power.
Fluctuations from any given power source are not what’s important to grid operators, they care about the total supply and demand at any given moment. Variations in wind energy happen slowly and can be easily smoothed out – they are actually less problematic than fluctuations in conventional energy sources because they can be predicted in advance. And the more wind energy that’s added to the grid, the less variable the resource as a whole becomes.
When conventional energy sources go down, they tend to drop suddenly and by a lot.
This means less – not more – reserve capacity is needed as a backup for intermittent wind. In Texas, grid operator ERCOT, for example, shows back-up for wind adds four cents to utility bills, compared to 76 cents for hedges against power plant outages, according to AWEA.
Wind farm on the Texas coast:
Out of 10 gigawatts of capacity, only 50 megawatts of fast-acting reserves must be ready to compensate for wind variations, says ERCOT. MISO, the grid operator in the Midwest, needs "little to no" fast-acting reserves.
AWEA notes that wind variability does increase the need for more slower-acting reserves, but those are less expensive sources of power.
"Conventional power-plant failures most often happen in a fraction of a second with no warning; the variability of wind is both gradual and predictable," Michael Goggin, AWEA’s Research Director told Midwest Energy News. "Gradual changes in wind output are relatively easy for grid operators to accommodate. On the other hand, rapid changes in electricity supply caused by traditional power plant failures require very fast-acting reserve generation. 24/7, you don’t know when a traditional power plant will go down. With wind you can do forecasting, you know tomorrow between 2 or 3 p.m. there will be a reduction."
Therefore, AWEA says the focus on the need for large amounts of "baseload" power is misleading, as is the need for lots of energy storage. The combination of power sources on the grid serves that function.
In fact, this is an argument for a diverse, balanced grid that runs on many energy sources. Wind energy helps build a more reliable and balanced electricity portfolio.
More than a dozen studies by US grid operators and the Department of Energy show that wind energy can reliably supply at least 20-30% of our electricity, and some say, 40%.
Read our article, Wind Energy Rescues Much of US During Polar Vortex.
Read AWEA’s report, Wind Energy Helps Build a More Reliable and Balanced Electricity Portfolio: