can i go off the grid with solar

Can I go off the grid with solar batteries? Excess solar energy explained

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Newer, more efficient solar panels and inverters have been in the news recently, but advancements in solar technology aren’t limited to standard equipment. Energy storage is also moving closer to mass-market adoption, and more installers are offering solar batteries and solar panel battery banks (a.k.a. solar-plus-storage) as an option for homeowners.

Solar-plus-storage systems include a battery that captures and stores the excess solar energy generated by the PV system, opening up the possibility of going “off the grid” – a tempting proposition for homeowners who want to sever their connection with utility companies by using renewable energy. As solar batteries become cheaper and more accessible for homeowners, more people are wondering, “Can I use solar batteries to go off the grid with my solar panel system?”

What does it mean to go “off the grid”?

Installing solar panels on your roof doesn’t mean that you’re off the grid. Most solar systems can’t consistently generate enough electricity to be a home’s only power source, which is why the vast majority of solar homeowners maintain a connection with their utility company. When you generate more power than you use, your utility gives you a net metering credit on your electricity bill. When you need to, you can then spend your credits to supplement your solar power with electricity from your utility company. If/when you don’t have credits, you’re simply charged the going rate for electricity at that time. For the average solar homeowner, this process typically means you’re generating more power than needed during daylight hours, and less than needed at night.

off the grid solar

If your solar panels can generate over 100% of your home’s electricity needs, then the credits you receive from your excess power generation could theoretically cover the costs of electricity needed in low-sunlight periods. However, this process requires that your home still stay connected to the grid. By truly going “off the grid”, you would need to sever your connection to your utility company. By doing this, you would lose the ability to purchase electricity from your utility in low-sunlight periods. This is why your home would need solar batteries installed to stay powered at night.

Can I use a solar panel battery bank to store my excess solar energy?

The battery storage technology that makes it possible to go off the grid does exist. If you install sufficient battery storage along with your solar PV system, you can store any excess electricity at the time of generation and then draw from it as needed later. You may be hearing talk of using “solar panel battery banks” as a means to harness massive amounts of storage capacity in order to become completely independent of the grid. Because off grid projects involve sizing enough energy to power your entire home, you’ll hear battery bank terminology used when a contractor is trying to estimate a total wattage for a combined battery system. In theory, you can find do it yourself methods for storing mass amounts of renewable energy with these connected battery arrays. In practice, however, going off the grid is more complicated than you might think, particularly if you live in an area with significant climate variation.

Residential-scale solar batteries on the market today can store the energy generated during the day for your home to use at night. This can be particularly beneficial in areas where net metering caps have been reached, or in areas where utility companies don’t have good policies for compensating homeowners who generate excess solar electricity.

The trickier proposition is capturing excess electricity generation in the summer, when solar power generation is highest, to use in the winter, when it is at its lowest. According to EnergySage marketplace data, the average solar shopper offsets 92.5% of their electricity use with their solar system – a significant amount, but not enough to go off the grid. Preventing total power loss in the event of a winter snowstorm or extended 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. In some places, particularly in remote areas, off-grid solar battery systems are the best (or even the only) option. More often, solar shoppers maintain their connection with their utility company, even when they choose solar-plus-storage solutions.

The good news: with or without storage, solar panels can still save you money

While you might not be able to completely go off the grid, solar panels are still a strong investment, and solar battery technology is becoming cheaper every year. With $0-down solar loans and solar leases, you can save money on your electricity bills as soon as your solar system is up and running, and you may even be able to get rebates or production-based incentives for switching to solar energy.

To learn more, use a solar calculator to get an instant estimate of what solar can do for your home. And as with any other major purchase, be sure to comparison shop for solar equipment and financing options before selecting the ultimate installer you plan to use.


This post first appeared on Mother Earth News

off the grid solar

25 thoughts on “Can I go off the grid with solar batteries? Excess solar energy explained

  1. ROBERT QUERY

    The info in this article appears to be about two years old (2017). My scant info says new battery
    technology is available since this article was published. Is there such a thing as a NiCad available?
    And where can I get battery specs and pricing?

  2. Solarman

    Robert there is the article mentioned TESLA 2.0 power wall and others have entered the marketplace. LG Chem has their residential energy storage system. Panasonic has an energy storage system and one of the larger residential storage system makers is Sonnen. The Sonnen system comes in 10kWh or 20kWh storage systems, use the less volatile LiFePO4 battery technology, NiCad batteries will not be cheaper than the LiFePO4 and tend to grow dendrites that short out and degrade the battery life of NiCad. The Sonnen system comes with its own built in Radian inverter/charger and has software that allows charging from a solar PV array and after hours charging from the utility in off peak hours. Instead of trying to bolt together a bunch of solar PV components from different manufacturers, Sonnen has developed their energy storage and control system around solar PV proven components and wired them into one box for ease of use. You can actually install less solar PV panels on your roof with this system in place.

  3. robert sands

    so if I buy the sonnen system stand alone can I put two wind terbines to generate power at night also because im in a high wind area so with solar panels and wind power and a generator and battery storage what would it cost to get all that to run a normal house and shed ? aprox price fully installed in blanchtown south Australia ?

  4. Solarman

    Sorry, Robert in Australia, the politics force alternative prices one way, then another. It seems to depend on who’s in power at the moment. That being said, Australia seems to also be the country with the highest per capita solar PV installations on residential homes.

    You have already shown an interest in alternatives, so have you done an analysis of your average monthly electricity needs? There are so many variables, one has to define, then compare with past electricity usage to see if it is possible. When all is said and done, you could have calculated your energy budget and designed a system that works very well for you. Then along comes a daughter or niece with a 1500 watt hair drier that screws up your daily budget in 20 minutes.

    I wish I could help you more with that, alas what I’ve noticed around the World is the “typical” daily demand from the many countries. Africa and India, solar PV with storage batteries only needs a couple of solar PV panels that could generate 1.5 to 2KW of power per day. The entrenched industrialized countries like the U.S. runs from an average 30kWh to 48kWh per day or around 1.25kWh to 2.0kWh continuous during the 24 hour period. In south Australia, I imagine there are the 43 degrees Centigrade days and nights without temperature relief. This is the American South West during the summer months. This is where one ends up using air conditioning 24/7 to stay comfortable. During those summer months, it is not unheard of using 7.56MWh for the month, which is why $1300 a month electric bills are common in the desert. In reality that’s something like a 42kW peak energy generation from solar PV or some other source (wind, micro hydro, etc.). It is becoming more feasible to over build one’s solar PV system, store excess energy during the day in an energy storage system, then at night use the stored extra to offset the utility’s practice of evening “demand charges”. Late at night and early morning, use the arbitrage algorithm in the energy storage system to charge up the battery for the morning peak, when solar PV isn’t making enough power just after sunrise.

  5. Begol

    Hi… I am from a monastery in the desert of Egypt and we use solar energy only during the day and generators of electricity during the night. But with any batteries or system You suggest that I use it for solar energy at night

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