Solar Batteries and Back-Up Storage

For most of my solar career, I have downplayed the importance of solar batteries on Cape Cod. While the future benefits of home storage were obvious, there were few compelling reasons why a homeowner should go to the expense of adding batteries just yet.

Massachusetts’ generous Net Metering program has made the grid the ideal place for a homeowner to store the excess energy produced by their solar system.

What’s more, with each one of the Bay State’s 351 cities and towns seemingly having different codes surrounding how and where solar batteries could be installed, the hassle of keeping up with all the shifting rules and regulations often made it impossible for installers to keep up. 

But the solar landscape is changing, and the number of customers who want to include home batteries with their solar installation is soaring. 

So it’s time for a post about the benefits of solar batteries and home back-up. We’ll look at the pros and cons of batteries, including the costs, incentives and potential savings they can offer. We’ll discuss the role that solar batteries might play in your home energy ecosystem and, most importantly, we’ll help you decide if solar batteries are right for you.

Understanding Solar Batteries

When the sun is shining brightly, your solar panels are likely to produce far more electricity than your home consumes at any given moment. Solar systems without batteries have traditionally sent this excess energy back into the grid in exchange for credits, which can then be used to pay for energy that the house needs when the sun is not shining. 

The terms under which that exchange of energy takes place is referred to as a Net Energy Metering (NEM) agreement that the homeowner signs with the utility company. NEM agreements differ from state to state, and Massachusetts currently has some of the most generous terms in the entire country.

If you add in a solar battery, that excess power first gets sent to the battery, and only after the battery is fully charged, will it be sent to the grid. This gives the homeowner their own private supply of excess energy that is independent of the grid.

Advantages of Solar Batteries

So why add solar batteries? If the grid already serves as a perfectly adequate place to store your excess power, why pay extra for a home storage set-up?

Backup Power

This stored energy becomes a lifeline during power outages, ensuring your essential appliances and critical loads continue to run smoothly. So two key questions to ask yourself are, how often do you lose power (and for how long), and do you already have a generator?

Some parts of the Outer Cape lose power quite frequently and electricity service can sometimes take days to get restored. Where I live, in Sandwich, on the other hand, it’s rare to lose power for more than an hour or two.

For this reason, I’ve never bothered to purchase a generator. Many people, who lose power more frequently, do have them. If that’s you, a battery may be an expensive additional layer of protection that you probably don’t need.

Increased Energy Independence

Some people just love the idea of being independent from the grid. While it’s impossible in Massachusetts to be completely off-grid, relying less on the grid, and having greater control over your energy consumption patterns is a big plus for some homeowners.

Maximize Solar Usage

Instead of sending excess solar power to the grid, you get to keep more of the clean energy you generate, minimizing the need to draw “dirty power” from the grid at times when your home consumes more than your solar system produces.

Disadvantages of Solar Batteries

Solar batteries are not for everyone, and there are certain considerations that may deter you from choosing to install one, at least for now.

Additional Cost

Solar batteries are not cheap. At the time of writing, purchasing one could easily run you $12,000-$15,000. And the cost of the battery itself may not be the only expense. Some towns demand the construction of a separate fire-proof space wherever the battery is installed. 

Yes, there are certain tax incentives that are available at least for the battery, likely not for the additional construction (speak to your tax advisor), but it’s still a substantial cost that may not be worth it for everyone.

Project Delays

Beyond the cost, it’s likely that the inclusion of a battery will delay a solar installation. The additional permits and interconnection approvals that are required will take longer and probably push your install date back by several months.

Financial Considerations

There are also substantial financial benefits to installing solar batteries, thanks to some relatively new programs that are designed to incentivize adoption, as well as future trends that are likely, one day, to impact Massachusetts.

Tax Incentives

The same 30% investment tax credits that applied to the purchase of solar panels was extended to solar batteries with the passage of the 2022 Inflation Reduction Act. 

As with solar, it’s a tax credit, not a tax rebate. As we always say, never take tax advice from a solar rep, speak to a tax professional to see if you qualify. But if you do qualify, the solar battery tax credit is a big financial advantage.

Eversource’s Connected Solutions Program

A core issue with solar energy is timing. Panels produce most of their energy during the daytime, when demand is typically low, especially in residential settings. Then, in the evenings, when demand soars, the solar panels are not producing anywhere near enough electricity to meet that demand, particularly in wintertime when the sun often sets before most people even get home from work.

This imbalance between supply and demand can be resolved using Virtual Power Plant (VPP) technology to connect thousands of individual home batteries into a single network.

If you join the Connected Solutions program, you give Eversource permission to tap into your battery’s supply of power at times of high demand. Don’t worry, the utility company won’t gobble up all of your stored electricity, and leave you without any back-up power of your own. 

They’ll also pay you for the privilege, so you can earn a return on your solar investment while also contributing to a cleaner, more resilient energy grid.

Possible Net Metering Changes

While Massachusetts currently has the most generous Net Metering terms in the country, that may not always be the case. Just look at California, long regarded as the best market in the country for rooftop solar. 

Then, in 2023, the California Department of Public Utilities drastically scaled back the value of credits the utility companies were required to offer for electricity that was sent back to the grid.

Now Californians only get one kWh of credit for every four kWhs they send to the grid. They’re better off keeping that power for themselves by storing it in a solar battery.

Other states with far less solar saturation than Massachusetts, such as Illinois, have already begun phasing out Net Metering in favor of other programs that incorporate storage in order to avoid some of the problems California faced. It’s only a matter of time before the Net Metering program in Massachusetts changes drastically, or disappears entirely. (Existing customers on the program will be grandfathered in, though).

Time of Use Pricing

Similarly with time of use pricing where electricity rates fluctuate depending the time of day, becoming more expensive at times of high demand. While time of use pricing is not currently a thing in Massachusetts, it’s quite common elsewhere, and many experts think it will come here in time. 

If so, storing cheap solar power that is generated during the day for use later in the evening, when rates are sky high, will be a huge money-saver for people with solar batteries.

Final Thoughts: Are Solar Batteries Worth It?

The answer to that question is, like most things when it comes to solar, it depends.

Power Outages – If you have a lot of power outages that take a long time to get fixed, you may want to consider a battery, particularly if you don’t have a generator and have a critical need for electricity, such as medical equipment.

Energy Independence – If reducing reliance on the traditional grid and taking control of your energy future aligns with your goals, a solar battery is worth considering.

Future-Proofing Your Home – Change is surely coming, and solar batteries will no doubt be part of that change. Net metering, virtual power plants and time-of-day pricing will likely soon be routine aspects of our relationship with the local utility company. Preparing for that future before it arrives will future-proof your home, possibly increasing its value.

If you would like to discuss solar batteries for your project, feel free to contact us to set up a no-pressure, informative chat about your options.