What are the advantages of adding battery storage to my solar project?
A battery backup allows you to store excess energy generated by your solar panels during sunny periods. This stored energy can be used during periods when your solar panels are not producing electricity, such as at night or during cloudy days, or when the electrical grid is down.
There are three primary advantages of having a battery:
1. The battery can provide you with power when the grid is down. In most cases, during grid outages, your solar system will be shut down for safety reasons. A battery backup can provide power during these outages.
2. Your solar system generally produces electricity when it is cheap, and without a battery you mostly sell your system's overproduction back to the grid at low prices. With a battery you can store some or all of your overproduction until the evening, at which time you can use it when electricity is expensive. This is commonly called load-shifting. This economic benefit is particularly important for California residents under NEM 3.0, which includes most systems agreed to after April 2023, because under NEM 3.0 you are paid particularly low rates for your overproduction. There are other ways to store your overproduction for later use, such as in your heat pump water heater or electric vehicle.
3. Having a battery helps the grid in its transition to clean energy. When you use less grid-provided energy, you alleviate the need for our electric utilities to produce power from non-renewable sources. While utilities are mandated by law to transition to clean energy over time, home storage will supplement wind, hydropower and utility scale storage in meeting our society's electricity demand during hours in which solar is not producing.
Installing home storage with batteries is expensive, though it is currently covered by a 30% tax credit. In addition to providing backup in the case of outages, a properly sized system can also produce economic advantages, especially for solar systems installed under NEM 3.0. For other systems, there is generally not an economic payback, so the benefit would mostly be for emergency backup. For carbon reduction, a heat pump or heat pump water heater would be a better investment.
There is a not-so-distant future where electric vehicles with bidirectional capabilities provide battery back up for homes as well, and batteries are also available for homes without solar.
QuitCarbon works with contractors that provide battery storage, and we'd be happy to discuss this more with you.