Can solar panels really power an entire house? (2023)

With advances in solar andbattery storage technologyToday, solar energy has emerged not only as one of the most efficient sources of energy, but also one of the most cost-effective ways to power a home. (The latest breakthrough istransparent solar panels, which may one day serve as power-generating windows in your home!)

If you have a suitable roof and can afford the upfront investment in solar panels and a storage battery, solar energy can be an excellent way to reduce your carbon footprint and provide long-term savings on your electricity bills.

However, the long answer to this question is more complicated.

While it is possible to take your home completely off the grid with the right solar and storage setup, it is more common to leave your home connected to the grid and get your electricity from a combination of your solar panels and the grid.

Without a storage system, your solar panels can only generate energy for your home during the day. At night, when your solar panels are not producing electricity, you get electricity from the grid.

Even if your home isn't fully solar powered, you can still pay off your electricity bills by selling excess energy back to the grid during the day through your local utility or a government program. Even if your home wasn't powered by solar energy 24/7, you could still generate enough clean energy to offset some of your electricity bills and carbon footprint.

How many solar panels do I need to power my house?

The average US household uses893 kilowatt hours (kWh) of electricity per month. That is almost 30 kWh per day.

The number of panels needed to meet this daily average depends on factors such as the amount of sunlight your home receives, the size of your solar array, and the rating of your solar panels (how many watts of power they produce). A little math comes into play here, but the equations aren't overly complex.

At a high level, there are three important steps:

1. Solar panel power rating: Convert watts to kilowatts

The rated output of a solar module is measured in watts (W). Panels today typically have aOutput power between 250 and 400 W, depending on which system you buy. This means they produce 250-400W of electricity per hour under peak conditions. But let's convert that to kW so you can more easily compare it to your own power consumption.

1,000 W corresponds to 1 kW, so the average living panel has an output of between 0.25 and 0.40 kW.

2. Estimate the hours of sunshine

The next step is to calculate the daily output of your solar modules. To do this, you need to estimate how many hours of sunshine per day your solar panels will receive (or the energy-producing conditions, since the panels can still be effective, albeit less efficient, on cloudy days).

Understandably, your home's sun exposure can vary drastically based on location, seasonality, landscaping, and more—but there are tools that can give you average estimates based on historical scientific data.Googles Project Sunroofis one such tool that goes further by also showing your estimated savings and environmental impact.

As part of any good solar contracting and installation process, companies do this sunlight analysis in your home before recommending which system to use and how many panels to invest in.

Calculate the number of panels you will need

Follow the equation below to get a rough estimate of how many solar panels you need to meet your energy needs. (Have a look at your electricity bill so you have the current electricity consumption of your house at hand.)

The amount of electricity your home consumes on average per day in kWh / (rated output of your solar panels in kW) x (average solar radiation in hours per day)

For example, if your home energy consumption is 30kWh per day, you want to buy 320W solar panels (0.32kW nominal power) and your home receives an average of 4 hours of direct sunlight per day, you need 23 panels to power your home Electricity.

30 / (0,32 x 4) = 23,4

This is of course only an average value. The number of panels you need to power your home depends on your power needs and many other factors. If you have a smaller roof or your home receives fewer hours of sunshine per day, you can purchase panels with a higher rating to generate more electricity per hour.

What happens to excess energy produced by solar panels at home?

In many cases, your solar panels generate more electricity than you use during the day. In this case, the excess energy is either stored in a battery if you have solar storage, or fed into the grid.

Utility companies use a system called net metering to measure the amount of energy your home is producing. They give you solar credits in exchange for the excess energy you send to the grid. Net metering allows homeowners to offset their electricity bills – even if you're still using electricity from the grid at night, you may not have to pay for that energy at the end of the month. The solar credits could offset some, if not all, of your bill. Talk to your local utility about net metering for more information.

Will solar panels power my house even when the sun isn't shining?

On cloudy days, solar panels still produce electricity, just more slowly. Normally on a nice sunny day you can generate enough energy to power your home all day long. However, some days you just don't get enough sunlight (or even partial sunlight) to fully power your home. Either a storage system or connection to the power grid is advantageous here.

A battery storage system allows you to use backup energy to power your home when your solar panels are not producing energy. This is the same back-up supply you use to power your home at night if you have an "off-grid" home.

Unless you have solar storage installed, your home will draw energy from the grid when your solar panels are not actively producing it (like at night).

Remarkably in the futureSolar panels might be able to produce energy at nightthanks to an incredible breakthrough by Stanford scientists. But this innovation is still far from having practical applications in the real world.

How much do solar panels cost?

Installing solar panels on your home requires a significant financial investment - especially if you intend to do soAlso install a storage system. The cost of just the solar panels varies by state, with recent data suggesting somewhere in between$13,000 to $19,000 for the solar array. However, this price does not include any federal tax credit reductions or local state exemptions to which you may be entitled.

Regional price averages calculated using national averages for6 kW solar system from Consumer Affairs. Visit the link for country-specific data.

While the upfront costs may seem like a lot, you can also calculate the long-term savings you'll get once your solar panels are up and running. Over the 20 to 30 year lifespan of your solar panels, you will likely more than cover the cost of installing your panels from these government tax incentives and exemptions, as well as the savings you'll make on your electricity bills and excess energy that you might put on your Utilities or your state can sell back. Check to see if your state has a buyback program.

Adding storage to your solar system will likely add another few thousand dollars up front, depending on the system you choose. However, this investment also has advantages. You may be able to take your home completely offline - allowing you to have a fully self-sufficient home that will come in handy during power outages. Not to mention, since you get all your electricity from your own utility, your electric bill will be $0 every month.

What if I can't install my own solar panels?

Most homeowners and renters are unable to install their own solar panels, whether due to financial constraints or the inability of the roof (not enough sunlight or the infrastructure doesn't support solar panels). But just because you can't install your own panels doesn't mean you can't reap the financial and environmental benefits of solar.

Community solar programsallow you to access the financial benefits of solar energy without having to install your own panels. Instead, you can subscribe to a local solar farm near you and support the operation of that solar farm in exchange for discounts on your electricity bill. While you're not getting solar power directly into your home, you're supporting the addition of more clean solar power to the overall energy mix on the grid. With a Community Solar subscription, you can save on electricity bills (not directly on your bill, but through the credits you get back)—and support our transition to a cleaner energy future.

Check to see if there are any municipal solar programs in your area. To find out more, stop byPerch Community Solar.