Renewable energy means we need energy storage, too

Following is a guest commentary penned by Mark MacCracken, CEO, of CALMAC, which designs and manufactures energy storage for commercial air-conditioning systems:

What’s with all the excess?

Storing excess renewable resources, such as solar and wind, is vital in securing an energy-efficient future. To understand just how vital energy storage is, consider this. Fossil fuel, such as coal and oil, are forms of stored energy, always ready when society needs it. Solar and wind are forms of “real” energy, coming and going irregularly. If we want to replace the value that fossil fuels afford our society, we have no choice but to add storage to intermittent renewable energy to make it readily available.

There are many forms of energy storage; some are grid-scale, some building-scale. Of all the types of energy storage available, thermal storage at the building for cooling is the least expensive, has the best overall cycle efficiencies, and stores the exact type of energy that causes electrical peaks on hot summer days, which is cooling. Nearly 80 per cent of the total electrical energy consumed in the US is used by buildings, and a large portion is used for air conditioning, typically during the peak hours of 1 – 6 pm when buildings are fully operational.

All forms of energy storage are going to be needed, both grid scale and the demand side (building scale) of the meter. As we continue to try to reduce our dependence on fossil fuels, we need it to trickle from the top down. Legislation on renewables without legislation on energy storage vastly diminishes its value. The good news … energy storage is now finally getting some attention in Congress. And that’s the peak of 2009!