Residential Battery Storage FAQ

What kinds of battery storage systems are available?

Currently, four main types of battery storage systems are available for residential homes.

Lead-acid: One of the oldest battery technologies, lead-acid batteries require maintenance and have a shorter life span than other battery technologies.

Lithium-based: Lithium type batteries are the most talked about and most prevalent battery chemistry. They use up less space than lead-acid and don’t require a lot of maintenance. However, they do cost more than lead-acid.

Nickel-based: These battery types last longer than lithium-based systems but sometimes use more toxic chemistries and are a bit larger overall.

Flow: This battery storage system uses a liquid electrolyte rather than a solid like the others. While this battery type is a safer way than the others to store power, and can do so very efficiently, they take up large amounts of space. Typically, these battery storage systems are used for larger utility-scale use due to their size requirements.

Why are battery systems popular right now?

With dropping rooftop solar costs, members want to build them with battery systems and harness the excess power generated. Nationally, some utilities offer programs and incentives that grant access to customer-owned battery storage systems to help reduce overall costs to supply power. CEC does not have any battery storage programs at this time.

Additionally, with more than 13% of the power generated in the nation coming from variable renewable generation (like wind and solar), many utilities are looking to invest in large-scale battery systems.

Lastly, news in the automotive industry dominates with talk of full battery electric vehicles and plugging them into your home for backup power.

Is battery storage right for me?

Even if a solar system comes equipped with battery storage, it doesn’t ensure you will have the backup power you need during a power outage. Powering the average consumer’s home, including HVAC systems, lights, appliances, well pumps, and water heating, requires a tremendous amount of energy.

Inclement weather variation plays a complicating factor. Having your entire home powered would require a solar array coupled with battery storage that is appropriately sized based on your energy consumption.

Battery storage technology continues to evolve, and battery banks are not readily available or cost-effective for the average consumer to purchase. For example, the average CEC home uses about 44 kWh daily—equivalent to the power capacity of about four Telsa Powerwall batteries. These batteries cost approximately $30,000 per battery and may only last one day, depending on whether the sun shines long enough to replenish the battery.

Members looking for a cost-effective and reliable backup power should consider a portable or permanent backup generator. Generators are much less expensive, run for more extended periods, and are readily available. More information on those systems can be found here.

Where can I find more information?

Many contractors who specialize in solar systems also sell battery systems.

Also, CEC’s energy specialists can serve as a helpful, reliable resource as members consider energy efficiency and energy choices. Talk to us about your options, like solar, energy efficiency, electric vehicles, and other programs that can help you save energy and money. We can also tell you about ideal charging times, like during off-peak hours, which helps keep energy costs low for all of our members. You can reach an energy specialist at 541-548-2144 or