Over the last decade, we’ve witnessed an extraordinary increase in solar panel-efficiency. The technology has improved so much that it’s now common for homeowners to be able to meet all their year-round energy needs with nothing more than a simple roof-top system. But solar energy is created on the sun’s schedule, not ours.
That year’s-worth of power will be generated in just the five or six hours when the sun shines most brightly on just the subset of days when it’s not too overcast. So, in order to take advantage of how remarkably efficient solar panels have become, you’ve got to have a way of storing the surplus energy generated during peak hours for use in the evening, at night, and on dark and cloudy days.
That used to mean installing a very powerful and, hence, extraordinarily expensive battery. But in recent years, Pennsylvania and many other states have passed net metering laws that:
Allow homeowners to send any surplus energy their solar systems generate back into the grid.
Require utility companies to compensate them at the very same rate they’d charge.
Net metering, in effect, requires your utility company to store any excess solar energy your system produces for you, eliminating the need for a battery. But solar panels aren’t the only things that have become vastly more efficient.
Battery technology has also massively improved. And it’s now possible to get a battery that will store enough power to run your entire home at a fraction of what you would have once paid. And, while net metering does allow you to avoid paying even that fraction, relying solely on it also comes with some disadvantages.
So, even if you live in a state like Pennsylvania where net metering is the law of the land, some homeowners might find that solar power will better meet their needs if they’ve also got a battery for storing excess energy.
What Happens When the Grid Goes Down?
Many people assume one advantage of solar panels is that they’ll continue to provide electricity during power outages. But that’s only true if you’re not using net metering.
Net metering means that any excess solar energy beyond what you're currently using gets sent back into the grid. But when there’s a power outage, the technicians working to fix it need to know they won’t be experiencing any sudden unexpected bursts of electricity.
As such, if you connect to the grid in order to take advantage of net metering, your solar system will be designed to shut down completely whenever the grid does.
So, if you live in an area subject to frequent blackouts or have other reasons for wanting backup solar power should the grid go down, you may want to consider installing a battery. How your system works will depend on whether use a battery along with net metering or instead of it.
Using both a battery along and net metering. Any surplus energy your system produces first goes to charging your battery. It’s only when the battery is fully charged that you’ll start sending excess energy back into the grid. Your solar system will still be set up to stop producing energy when the grid goes down for the very same safety reasons. But you’ll at least be able to draw on the battery to keep your home running until the power comes back on.
Using a battery without net metering. Since you won’t be sending any power back into the grid, your panels will be able to continue to produce solar energy even when the power goes down without endangering any technicians.
Laws Can Change
As you can well imagine, utility companies aren’t in love with net metering laws. In some states they’ve managed to successfully lobby against it.
In Nevada, for example, utility companies managed to decrease the price they have to pay homeowners for solar energy as well as increase their monthly grid-service fees.
Though nothing like that appears to be on the horizon in Pennsylvania, anything can happen. And installing a battery as part of your solar system is a way to be prepared just in case it does.
Service Fees
Every customer of a utility company has to pay monthly service fees regardless of whether they wind up drawing any power. That means that, even if your solar system produces enough electricity to run your home, if you’re using net metering you’re going to be hit with that monthly fee.
It won’t be very large. But you can avoid it entirely with a battery so long as you’re confident that your solar system will be generating enough power to run your home and, hence, won’t need the option of drawing power from the grid.
The only way to avoid a monthly fee is to not be a utility company customer. So, if there’s any chance you’re going to need power from the grid, you’ll have to live with a monthly fee regardless of whether you have a battery.
Those are the basic considerations that might make installing a battery a better option. And, of course, you could always wait to see how things go and install a battery later should net metering laws change or other factors favoring having your own means of solar energy storage come into play.