How Many Solar Panels Do I Need to Power My Home?

February 3, 2020
How Many Solar Panels Do I Need to Power My Home?

You already know that going solar can save you money on your monthly utility bills. Even one panel will begin delivering measurable savings on your electricity bill. And as you add more and more modules to your solar system, these benefits only increase.

But how many solar panels do you actually need for your home?

The short answer is – it depends. That’s because every homeowner has slightly different needs including energy consumption (kilowatt hours kWh), financial situations, and environmental goals.

However, let’s assume you want to generate enough solar power to reduce your electricity bill by 30% or more. With this as our starting point, a 5kW photovoltaic (PV) solar system is sufficient for most California homes. If you install 250W high quality solar modules, you’d need about 20 panels – spread across 330 square feet roof space or land.

But as you’ll soon see, even this is a rough estimate.

Installing Enough Panels for Today and Tomorrow

The exact number of solar panels required depends on several factors – including your historic energy consumption and the amount of usable roof space you have (after accounting for shading, chimneys, vents, and other obstructions).

The price of grid electricity in your area is also a significant variable.

California, for example, has some of the most expensive utility power in the country. As such, going solar can save you a lot more money than if you installed a similarly-sized installation in a less expensive market like Texas. And because utility rates in California keep trending upwards, your savings will only grow with time.

California vs US Electricity Rates

But it’s also important to factor in your future energy needs as well.

Here’s why.

According to Jevons Paradox, becoming more energy efficient actually makes you consume more energy overall. Solar customers, for example, often end up using their air-conditioners more than their non-solar counterparts do. They also buy more “smart home” devices, appliances, pool pumps, and other power-hungry accessories.

Electric vehicle charging for homes

This is particularly true in California, where nearly 40% of all electric vehicle (EV) drivers use solar power to charge their cars.

But why does all this matter?


Although it’s possible to add additional solar panels later on, it is much cheaper to install the right number of panels from the very beginning.

For starters, you lose a lot of money in the form of higher electricity bills if your installation isn’t large enough to cover your future energy needs. Moreover, retrofits and expansions are costly – especially if you have to upgrade your electrical panel to accommodate future add-ons like EV-charging.

Our Approach to Residential Solar Installation Design

At Bright Planet Consulting, our goal is to optimize your solar savings – for both today and tomorrow.

To accomplish this, we provide our customers with the following complimentary services (free of charge).

First, our team does a thorough analysis of your property, historic electricity consumption, and local utility rates. We then discuss your long-term goals to accurately forecast your future energy needs.

Next, we draft out a written proposal that clearly outlines:

  • The exact number and type of solar panels required.
  • Your projected savings (every year – for the next 25 years).
  • The payback period of your solar installation and ROI.

In addition in installing a solar system for you, our standard service also comes with a complete electrical panel upgrade. You may even qualify for installation of a 220v outlet and JuiceBox EV charger as part of the project!

If you’d like to learn more about our expert solar installation services, schedule a free 15-minute consultation by clicking here.

To compare solar financing options and see how much you can save, use our solar calculator below.

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We interviewed a number of solar vendors, and selected Bright Planet Solar. We started the process in September of 2019, and completed installation in early December. Bright Planet was the most knowledgeable, and had the best pricing by far. We saved a ton with them, and the installation was done with the most reliable equipment on the market today. The installation was not the smoothest. We had a number of issues to deal with due to the configuration of our home. Bright Planet just kept coming back to work on it until it was completed and completed really well. The final solution met all our needs. The system is aesthetically pleasing, and works really well. I would highly recommend if you are looking to install solar, that you work with Bright Planet Solar.
David Strong
Bay Area