Huge Hurdles for Renewable Power Storage
A key mechanism for fighting climate change, some environmental activists and politicians say, is to increase the amount of electricity produced from renewable sources that do not emit carbon dioxide (CO2).
As nearly everyone knows, a key problem with wind and solar power is their intermittency, which makes those power sources difficult to accommodate in the electric grid. To provide power when wind and solar aren’t producing energy, and to regulate their variable power output when they are, requires expensive “backup generation,” largely from running fossil fuel or nuclear power plants at less-than-efficient levels: On-again, off-again is never as efficient as keeping a power plant running at a steady pace.
The intermittency burden increases as the percentage of renewable sources contributing to the grid is increased. For Texas’s ERCOT grid with 10.6% wind, the additional costs are approximately $19/MWh for generation plus approximately $6.50/MWh for transmission.
To overcome renewable power’s intermittency problem and thus get the full CO2-reducing benefit from expanded renewable power, the industry is searching for ways to store excess electricity generated when the wind blows and the sun shines, to be released when wind turbines are not turning or solar panels are not generating power due to clouds or at night.