Grid tied vs. solar battery backup on EnergySage

Hybrid solar systems: which pairing of on and off-grid is right for you?

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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 hybrid solar system. Here’s everything that you should keep in mind when you’re comparing hybrid solar panels to typical grid-connection or off-grid options

What are hybrid solar panels?

A hybrid solar panel system is a combination of a grid-connected and storage-ready apparatus that provides consistent energy supply during day and night. The hybrid system stores energy for later use in one or multiple solar batteries but then can also pull from the grid in high energy use periods like hot summer months. Any solar plus storage system that is not meant to be entirely off-grid will be a hybrid 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 approximately 95 percent of their annual electricity use with solar – a significant amount, but not enough to go truly “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.

Hybrid solar panels: using a solar battery backup with your grid-tied solar 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 and use a hybrid solar 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.

However, in the case when you do have access to utility net metering, installing a hybrid solar system can still make a lot of sense in an effort to maximize off-peak electricity prices. Thus, when your solar panels are overproducing, you can store it in your storage array or in the grid depending on the context of peak pricing. Then you can pull from the grid only when prices are below market average at off-peak times. For example, during warm summer months when panel production is high but so is household energy use, you can opt to store all extra panel production in your batteries in an effort to be less grid-reliant in a time when energy prices are surging.

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.

Three Tips for Solar Shoppers

1. Homeowners who get multiple quotes save 10% or more

As with any big ticket purchase, shopping for a solar panel installation takes a lot of research and consideration, including a thorough review of the companies in your area. A recent report by the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL) recommended that consumers compare as many solar options as possible to avoid paying inflated prices offered by the large installers in the solar industry.

To find the smaller contractors that typically offer lower prices, you’ll need to use an installer network like EnergySage. You can receive free quotes from vetted installers local to you when you register your property on our Solar Marketplace – homeowners who get 3 or more quotes can expect to save $5,000 to $10,000 on their solar panel installation.

2. The biggest installers typically don’t offer the best price

The bigger isn’t always better mantra is one of the main reasons we strongly encourage homeowners to consider all of their solar options, not just the brands large enough to pay for the most advertising. A recent report by the U.S. government found that large installers are $2,000 to $5,000 more expensive than small solar companies. If you have offers from some of the big installers in solar, make sure you compare those bids with quotes from local installers to ensure you don’t overpay for solar.

3. Comparing all your equipment options is just as important

National-scale installers don’t just offer higher prices – they also tend to have fewer solar equipment options, which can have a significant impact on your system’s electricity production. By collecting a diverse array of solar bids, you can compare costs and savings based on the different equipment packages available to you.

There are multiple variables to consider when seeking out the best solar panels on the market. While certain panels will have higher efficiency ratings than others, investing in top-of-the-line solar equipment doesn’t always result in higher savings. The only way to find the “sweet spot” for your property is to evaluate quotes with varying equipment and financing offers.

For any homeowner in the early stage of shopping for solar that would just like a ballpark estimate for an installation, try our Solar Calculator that offers upfront cost and long-term savings estimates based on your location and roof type. For those looking to get quotes from local contractors today, check out our quote comparison platform.

This post originally appeared on Mother Earth News.

4 thoughts on “Hybrid solar systems: which pairing of on and off-grid is right for you?

  1. ted rees

    I’m looking for a system that operates just like a grid tied solar PV system, but that can also run from a battery.
    The solar PV system takes the panel power and dumps it to the grid. Your house takes power from the grid. In other words, the PV system doesn’t care about the house loads, because the grid dominates the output of the inverter.
    So, I want a system with that kind of inverter, but instead of feeding it with solar, feed it with a battery.

    Why? Doing it this way allows the batteries to be fully cycled, every day regardless of the variations in the house load. Excess battery power can drive the grid to reduce grid emissions. Not enough battery power can be made up by the grid.

    No muss, no fuss. Just connect this system to your mains through a breaker, and all of your house needs are guaranteed by the grid, and your battery is used fully every day to be charged when rates are low, or grid emissions are low, and discharged when rates are high, or grid emissions are high.

    Why isn’t this option offered?

    1. Tom

      Likely because the chargers for the batteries are not 100% efficient, more likely in the range of 65-75%
      Also, if your system is using lithium ion batteries, they have a limited number of charge/discharge cycles ( around 300)
      It would also require a different wiring configuration than a standard grid tied system.
      The easiest way would be to run from the panels through a charge controller to the batteries then have the batteries feed a grid-tied inverter so you are going to have losses in between the solar panels and the batteries, losses in between the batteries and the large grid tie inverter to either feed the utility or feed the house.
      Unless you live in an area where the utility has to pay for the avoided cost of power rather than just the wholesale rate for excess power, your best bet is to dump excess power into an electric hot water heater, at least the power does something for YOU
      rather than giving it away

  2. Guylene Lawler

    We have a system through Sun Run that we paid cash for. But unfortunately to remain comfortable last year we ended up with a yearly bill for over $1200.00. We kept our thermostat at 78 degrees most of the Summer. We are interested in a battery back up.


    Hi. Nice report in term of the hybrid system which is the way that I’m planning to go. I’m currently have a grid tie 9.30kW system (31 solar world 300W panels) and I’m interested to instal a sonnen eco10 or 12 to start. To my understanding, I can increase my backup by adding 2kW batt based on my needs. What are your thoughs and/or feedbacks on this matther? I’m looking for something simple and reliable. Thx in advance x your support!


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