Grid-scale storage? How about building-scale storage too?


By: SGN Staff


We've covered the evolution of grid-scale storage in great detail over the years. Most recently, we told you of the pending tax credits for storage.


But storage doesn't have to mean a giant stack of batteries. Thermal storage - in particular ice-based storage - can make a real contribution too, as you will read in this guest editorial from Mark MacCracken. - Jesse Berst


By Mark MacCracken


Our power grid is decreasing in reliability while demand is simultaneously increasing. That is certainly setting the stage for a major problem in the U.S., especially as summer temperatures continue to soar.


This year, heat waves have already been fatal in the Southwest and residents in northern California have been asked to reduce energy consumption to avoid blackouts. But do utilities really expect customers to be uncomfortable and hot in order to conserve power? The average person is not going to think about the power grid when making a visit to the thermostat.


Why storage is so essential

 Energy storage allows people to crank up the air conditioning without adding any stress to the power grid. Most renewable energy does not provide a consistent flow of electricity. The amount of sunlight differs throughout the day and the wind isn’t always blowing. Using energy storage allows for power to be dispatched quickly in order to compensate for intermittent availability. This also allows for two-way flow of electricity and will ultimately keep electricity prices lower than if new power plants and infrastructure needed to be built.


This is why recent legislation, policies and programs have been proposed to encourage the implementation of building-side energy storage. This year, senators from across the country introduced the bipartisan Storage Technology for Renewable and Green Energy Act of 2013, offering a tax credit for the deployment of energy storage technologies that can be used to lower peak demand. While attempts to foster adoption on a national level, some states, most notably California, are trying to achieve this with their own policies. The California Public Utilities Commission (CPUC) recently released a proposal that would ultimately incorporate 1.3 gigawatts of storage into the grid by 2020. The CPUC also introduced Resolution E-4586. This will implement a permanent load shifting (PLS) program to the public utilities, SCE, PG&E and SDG&E.  


The PLS program supports technologies such as thermal energy storage and batteries that can shift energy usage from one period of time to another on a recurring basis. This is done through storing energy generated during off-peak times, or when energy is in low demand such as night, and using the energy during times of peak demand.