The Importance of Energy Storage
Synergy Solar has over 20 years of experience installing solar and want to continue to install solar in a responsible way that supports the grid. Long ago, we anticipated the utility changes and started installing Energy Storage Systems (ESS), aka. batteries, with all our solar installations with few exceptions. Here are some of the reasons ESS are so important.
Grid Strengthening
As PG&E “strengthens” the grid we are finding there are more power outages in places that had been having less. To reduce wildfires and other safety issues due to downed power lines PG&E has been installing safety switches on the lines that quickly detect an issue such as a tree branch falling on a line. These switches will disconnect power much like the Ground Fault Circuit Interrupter (GFCI) receptacles in your kitchen or bathroom. This makes things safer but increases power outages. With many folks working remotely, having medical needs that require power or just like to keep the refrigerator on, ESS have become the best clean, quiet backup power source.
How Batteries Support the Power Grid
We are lucky to live where many households have adopted solar. This is good but many folks are out of the house midday when their solar is producing the most energy and a lot of solar gets exported to the grid. This causes issues for the grid, especially during high solar production times of the year. When you use an ESS to store and then self-consume your solar energy it reduces expensive, peak-priced electricity consumption and peak strain on the grid. The following day your ESS will recharge from your solar, which reduces the strain on the grid that spinning the meter backwards with excess solar causes. We all know too well that the grid needs help, and having energy storage as part of your system is a great way to contribute. Helping the grid be more stable and reliable benefits everyone as we move into the energy future.
Net Billing Tariff (NBT) vs. Net Energy Metering (NEM)
NBT and NEM define how you’re compensated for solar energy exported to the grid. Under today’s NBT rules, solar without storage rarely makes financial sense. The big change is how utilities credit the energy you “spin” backwards. Under NEM 1 and NEM 2, credits were worth the same as the energy you bought, so systems were designed to overproduce in summer, bank credits, and use them in winter, often resulting in a minimal annual true-up.
Now, exported energy is credited at much lower values for most of the year, so good system design focuses on minimizing exports. Adding energy storage lets you store excess solar during the day and use it during peak times and after sunset. The system manages this automatically. Batteries aren’t sized to carry all your summer surplus into winter, so some exporting will still occur, but far less than with solar alone.