Solar + Batteries: Is renewable home backup power finally here?
For years, solar customers have waited for a reliable and affordable way to access their solar power in case the grid were to go down and truly be energy independent of power outages. But for years batteries have been too expensive, too custom-built and just not appealing enough for most solar customers to make the jump.
That is changing, according to Kelly Curtis from Solaroo Energy, a South Jordan-based solar contractor. Here are three key questions people should know about solar battery backup systems.
Why have batteries come down in price so much?
Just like with any technology, the more it is implemented and used, the cheaper it becomes. The solar industry has seen its solar modules and inverters come down drastically in price over the years, and it seems the same is happening with batteries.
“The solar battery industry has really benefited from the electric car market,” Curtis explains. “The lithium-ion batteries used in most of the hybrid and electric cars are now being manufactured for solar storage. The economies of scale have really driven down the price. You can now get a battery system for under $7,000, where just a year or two ago, the same amount of storage would be $20,000 or more.”
The cost of the battery cells themselves isn’t the only reason for the cost savings. Improvements in technology have also reduced the cost of inverters, battery components, and even installation labor.
“Labor is a big cost. It used to take us days to install a backup system because most systems were so custom built and required rewiring a lot of your house,” Curtis notes, “But now they are simple and straightforward. We can install a system in just a few hours.”
Can you really run anything of substance with your backup power?
How much you can run at once and for how long are the two ways to measure your storage. Continuous max output will determine what appliances, lights, and electronics you can have on at once. Total kwh capacity is the total amount of energy your battery has to discharge before it is empty. Both have improved over time.
“Battery solutions have now compensated to accommodate most home power needs,” Curtis says, “but you can backup the just the essentials, or have your entire house continue just as normal when the grid goes down.”
How long will your battery system last?
Before lithium-ion batteries became affordable enough for residential home energy storage, lead-acid batteries were commonly used to store solar power. Lead acid batteries can work for storage, but maintenance, size, ventilation, cycle count and other limitations make lithium-ion batteries much more appealing. The biggest advantage to lithium-ion batteries might be the life of the battery cells.