Implementing solar energy generation can be tricky, because peak usage is the same time when the sun starts to disappear, thus, reducing electricity generation. Creating a way to store energy during the day and then deliver it when needed is one way to make solar energy a more practical solution, and Arizona Public Service Company have been testing a new 1.5 megawatt-hour energy storage system.

The size of a shipping container, and with the ability to generate the equivalent power output of 1,200 hybrid cars or 300,000 cell phones batteries, the energy storage device is being tested at the Doney Park Renewable Energy site in Arizona in an effort to determine the benefits for storing electricity and putting it onto the grid when customers need it the most.

“We plan to study a number of things, including how we can decrease equipment stress on high demand days and how we can provide solar energy to our customers after sundown,” says APS Director of Energy Innovation Barbara Lockwood. “This pilot has great potential to change some of the ways we deliver electricity in the future.”

“The steadier flow of electricity on peak days could keep our equipment healthy for longer periods, so we can improve reliability and keep maintenance costs down,” says APS Energy Storage Project Manager Joe Wilhelm. “In the future, if a piece of equipment fails and causes an outage, we could also dispatch energy from storage units temporarily until repairs were made.” “Energy storage can make renewable resources more reliable for our operations teams and for our customers. One of the busiest times on our system is between 5 and 9 p.m. That’s when many customers get home from work, turn on the lights, the TV and the air conditioner. However, by that time, solar systems have largely stopped producing for the day,” says Wilhelm. “With storage, we can gather solar energy during the day and dispatch it in the evening, when it provides the greatest benefit to our customers.”

The energy storage pilot will be two-fold. In 2012, the energy storage system, which was developed by Electrovaya Inc., a lithium-ion battery manufacturing company, will reside in an electrical distribution substation. At a later date, the system will be trucked a few miles up the road to support a neighborhood-scale solar power plant.

In the substation, the system will store energy when it is inexpensive and the electricity flowing through the substation equipment is at lower capacity. Then, APS will have the ability to dispatch the energy at times of higher demand when electricity is both more expensive to purchase or produce and equipment is at maximum capacity.

Source: APS