How to choose a solar battery bank That’s right for your home ?
Adding a solar battery bank to your solar installation can have several benefits. You’ll be able to survive power outages by running your home on just solar power, and you can use the energy stored in your batteries to power your home during peak usage times when electricity from the utility is more expensive.
We’re not quite yet at the point where battery storage can pay off its financial cost with savings on your electric bill, but you can’t put a price on the peace of mind you feel knowing that your solar panels and batteries will be enough to keep you warm and safe if (or when, if you live in PG&E territory in California) the power goes out.
If you’ve decided to get ahome solar battery, but have yet to determine how much energy storage you’ll need, let’s dive in to figuring out how much battery capacity you’ll need.How many batteries do you need to run a house?
The key question to ask when choosing a solar battery bank is “how many batteries do I need?” The answer to that question depends on what you want to power, how long you think you might need the backup, and the type of batteries you choose.
What You Can Power With A Solar Battery Bank
If the power goes out, what do you want your life to be like? If you need to have full power, you’ll be looking for what’s called a “whole home battery system,” which can keep your air conditioned, your food frozen, and your clothes dryer running, but not all at the same time (more on that below).
If you can get along with keeping your food cold and the lights on, you can choose to power “critical loads” only. That would keep the A/C and electric stove off, but run refrigeration, wi-fi, lights, and outlets to charge devices.
Calculating Your Needs
If you’re looking to power your whole home during an extended outage, you’ll need to know your average usage per day. You can look at your electric bill or login to your utility company’s website to find out how many kilowatt-hours you use in a month or year.
If you’re looking at monthly usage, be sure to choose the month in which your usage is highest. You don’t want to lose power for three days in July and go without A/C because you didn’t choose enough battery capacity.
For our example of PG&E territory in California, it looks like usage for the average residential customer has two annual peak months,July and December, which makes sense, because that’s when you’ll be needing HVAC running. Those peaks hover around 675 kWh in a month, or about 22 kWh per day.
If you’re anticipating an outage in PG&E territory, you’ll want to pair your solar panels with at least 22 kWh of energy storage capacity. Oh, and make sure tocalculate how many kWh your solar installation can make in a day, as well.
Critical Loads only
Photos from Unsplash by Federico Bottos, Alessio Zaccaria and Ronan Furuta
