Solar energy and how to store it have always been natural partners for homeowners interested in reducing their carbon footprint. But the idea of residential solar storage made little sense due to the cost of solar batteries vs. options to export electricity to a local utility provider.

All of that is finally changing. Solar battery costs are coming down. This opened the door for the industry to develop new technologies to provide better on-site solar storage options to residential consumers and turn itself into a booming market.

What is a solar battery?

A solar battery functions in the same manner as any other battery, but that's where the similarity stops. There are four main types of batteries used to store electricity from residential solar power systems. All offer differing results, and all come at different prices.

Lead acid: This is not your average automotive battery. It's large, bulky and heavy, but it's also inexpensive, dependable, and well tested. New technologies are closing in fast, offering longer warranties and better prices, but these probably aren't going anywhere.

Lithium-ion: This family of batteries is already used in more applications than any other. The prismatic types, specifically lithium iron phosphate (LFP) batteries, are commonly used in solar energy storage.

Flow: Flow batteries are a relatively new entrant to the residential solar arena. They contain a water-based solution of zinc-bromide. These are the best batteries for long-term storage because they last for decades with little maintenance and the internal electrolyte materials can be repurposed.