Battery Backup Scams – What to Know

You’ve gotten or are getting solar panels to save money and go green. Now you might be seeing ads for battery backups for your home. Do you need one? The articles, hype from Tesla, and your friends might make you think yes, but that’s probably not the case.

Let’s start with some basics.

How Does Solar Battery Backup Work?

The popular image of a building that has switched to solar is that once a homeowner installs their solar panels, the local power authority, like PSEG, is entirely out of the picture. That’s rarely the case.

Instead, what happens is that the energy generated by the building’s solar panels powers its electrical needs. Any extra energy generated is sold back to the local energy company as part of “net metering.” In New York, surplus energy gets sold back, becoming a credit or “bank” for heavily overcast days when the panels create less energy or when your energy needs exceed production, including hot days when you’re using air conditioning non-stop. 

So electrical usage comes first from what your solar panels generate, with needs beyond that comes from your credit or banked amount. Only when that is exhausted are you charged for any energy from PSEG.

People tend to buy house batteries for one of two reasons. The first is if they want to live entirely off the grid. The other is as a backup if the local power grid goes down. Neither option is as simple as it sounds.

For safety reasons, solar systems are designed to shut down in the event of a blackout. This way, no power leaks from your solar system to the neighborhood power lines (remember – usually you’re transmitting the excess energy to your power company) while service technicians work to restore power in the area.

Being able to use your solar power generation during an outage has traditionally meant using an inverter to ensure your system is isolated from the local grid and then switching back when area power is restored. The one benefit of those expensive house batteries is that they’re usually designed to make this switch automatically.

Does Your Solar System Need a Battery Backup?

No, it doesn’t. More importantly, those fancy house batteries or PowerWalls won’t provide sufficient energy during a blackout – that’s the secret battery manufacturers don’t want you to know.

The average top capacity of an expensive house battery is 14 kilowatt-hours. The average Long Islander uses more than that in one day when you add up-lighting, appliances, etc. If you have a family, you’re using more than that when you add in each individual’s devices, TVs, and so forth. You can check your electric bill for details about your electrical usage. Still, on average, even a Tesla PowerWall is only going to provide maybe half of your needed power for a day. The more members of your household relying on power for phones, laptops, etc., the lower amount of time it will last.

The truth that house battery salespeople rarely mention is that “whole house battery backups” are intended to ration electrical usage and minimize major appliance use. In other words, they’re only meant to keep the lights on, the fridge and electric stove running, charge your devices, etc., but those loads of laundry should wait until full power is restored. The power-hungry game systems? Put those on hold, too.

Those display homes used to showcase an off-the-grid, battery and solar-powered system? They’re usually smaller homes designed for just one or two people. They are exceedingly energy-efficient, not the typical home with a family with lots of devices used independently at the same time.

Even on a rationed energy basis, house battery backup systems are intended for a short power outage. They’re not meant for an outage that lasts for an extended period.

So house batteries technically work but are unnecessary for the average Long Island homeowner. Since they tend to be expensive – especially if you want to buy enough to power all of your needs – it’s an unnecessary cost.

Lower Your Energy Costs with Greenleaf Solar

Have more questions about installing solar panels? GreenLeaf Solar is one of America’s most trusted and reliable solar companies, serving residential, commercial, and municipal installations. We’ve helped thousands of Long Islanders switch to high-efficiency solar systems. Contact the solar energy experts at GreenLeaf Solar now for a free consultation.