Intermittent Renewables Require Energy Storage

Jim Gagnepain · Joined: 14 Feb 2006 Posts: 5 Location: Fort Collins, CO

Because of the intermittent nature of both wind and solar, energy must be stored in the form of potential energy. There are a number of different storage techniques. The most promising for large scale electricity generation is water storage, whereby water is pumped uphill, and stored to later turn turbines. This process has an 80% efficiency rate, which is higher than other storage techniques.

This is not a new technology. Today, 90 GigaWatts of electricity, or 3% of our global generation uses pumped water storage. Here's a link for this statistic:

http://en.wikipedia.org/wiki/Grid_energy_storage#Pumped_water_storage

The other plus of this storage technique is that the end result is hydroelectric power, the most efficient power generation on the planet. It's also non-polluting.

So what's the downside? One of the main problems is the current structure of our power companies. They don't typically invest in reservoirs, and if they did, they could be subjected to a lot of local water regulations. For a company that currently simply places orders for coal, and burns it on-sight, this would require a paradigm shift.