Solar offers more than just an opportunity to reduce your carbon footprint. When you install solar panels on your roof, you are a step closer to taking your electricity production and consumption into your own hands. One of the biggest decisions solar shoppers have to make is whether to install a standard grid-tied solar energy system, a solar battery backup, or a fully off-grid solar energy system. Here’s everything that you should keep in mind when you’re deciding between grid-tied solar vs. an off-grid solar battery backup system.
Why many homeowners choose a grid-tied solar system
Off-grid solar technology is becoming more advanced every year, and a growing number of companies are manufacturing solar batteries for home. If you install battery storage along with your PV system, you can store excess solar electricity when it’s produced and then use it as needed later. Theoretically, this means that you can completely sever your connection with your electricity utility. In practice, it often makes more sense to stay grid-tied, particularly if you live in an area with significant climate variation.
Most of the solar batteries for home use available today, like the Tesla Powerwall, are designed to store solar energy generated during the day for your home to use at night. This can help you reduce your reliance on utility electricity by storing your excess solar power at home instead of feeding it back into the grid.
The trickier proposition is generating and storing enough extra solar electricity in the summer when solar power generation is highest to cover your future needs in the winter, when solar potential is at its lowest. According to EnergySage Marketplace data, the average solar shopper offsets 86 percent of their annual electricity use with solar – a significant amount, but not enough to go fully “off the grid.”
Preventing total power loss in the event of a winter snowstorm or an extended period of overcast days would require a lot of storage capacity, a very large solar panel system, and a significant financial investment to install. While it is technically feasible to go off the grid with solar batteries, it’s rarely cost effective when compared to the benefits of staying grid-tied.
Can you go off-grid with your solar panels?
Grid-tie solar is the best option for many homeowners, but there are plenty of situations where taking your home off the grid with a solar battery backup makes sense. In some places, particularly in remote areas, off-grid solar battery systems are the best (or even the only) option. There are a few criteria your property should meet to be a good fit for off-grid solar.
First and foremost, you need to have very low electricity demand. If you construct a net zero energy home or conduct major home energy efficiency retrofits on your existing home, powering your property with off-grid solar-plus-storage can be a feasible option. You also need to have the financial capacity to invest in a solar battery backup, which will add thousands of dollars to your solar installation.
Even if you don’t take your home fully off-grid with a solar battery backup, there are still opportunities for you to use solar-plus-storage technology. Many do it yourself solar options with batteries are available if you want to install solar-powered lighting or electrify outlying buildings on your property, like barns and tool sheds. Tiny houses, boats, and RVs are also great candidates for solar-plus-storage – they have comparatively small electricity needs and are already designed for “off grid” use.
Using a solar battery backup with your grid-tied solar energy system
For the average solar homeowner in the United States, it usually makes sense to maintain a connection to the utility company. However, even if you don’t choose to go fully off-grid, you can still install a solar battery backup with your PV system.
Solar-plus-storage systems that include a battery are particularly beneficial if your utility doesn’t have a good policy for compensating homeowners who generate excess solar electricity. For example, some utilities don’t have retail rate net metering for solar, which means you won’t receive a full bill credit for solar electricity that you send back to the grid. If you live in California, net metering 2.0 means that new solar homeowners will be enrolled in time-of-use rates with their utility. As a result, the credit you receive for your solar electricity will vary depending on the time of day – electricity sent back to the grid during peak hours generally results in higher value credits. In both of these cases, you can benefit from storing your excess solar energy at home even though you’re still connected to the grid.
In addition to making it easier for you to manage your solar electricity generation and use at home, solar batteries can provide a few hours of backup power in the event of a power outage. If you’re already installing a solar PV system, including a battery can be more cost-effective in the long term than a diesel-powered backup generator.
While most homeowners can’t go completely off the grid with a solar battery backup, solar panels are still a strong investment, and storage technologies are becoming cheaper every year. Even if you don’t invest in energy storage now, you can ask your solar installer to make your system “storage ready” so that, a few years down the line, you can easily install a solar battery backup. Use the EnergySage Solar Marketplace to get multiple quotes from pre-vetted local solar installers and find the right solar-plus-storage option for your home.
This post originally appeared on Mother Earth News.