Don't worry—there will be no math. That's what the pros are for.

When you consult with them, solar companies will calculate how many panels you would need to generate a certain amount of energy. They take into account hours of peak sunshine per day and your home's average energy consumption. But you might want to estimate the size of your system without getting a pro involved. To that end, we have prepared this simple outline.

Small, medium, or large—no matter your household size, a solar energy system can lower your energy bill considerably or even preplace it.

What Size System Would Replace Your Energy Bill?

Different households have different energy requirements. Some are equipped with EnergyStar appliances, others with legacy units the house came with. Some have no need for air conditioning, while others couldn't get through a summer without it. Some have one or two residents, others four or more.

Here are the ideal capacities of grid-connected solar energy systems based on household size. It's important to remember that even a smaller system will lower your energy costs considerably, even if it isn't powerful enough to replace the bill.

Small home: 1-2 people

🏠 👤 👤

What you can run:

  • Fridge
  • Energy-efficient lights, less than 10
  • LCD TV
  • Standby appliances
  • Washing machine, 1 load a week
  • Dishwasher, 2 loads a week

Your ideal system: 1.5 kilowatts

Medium home: 2-3 people

🏡 👤 👤 👤

What you can run:

  • Fridge
  • Ceiling lights, 10-20
  • LCD TV
  • Standby appliances
  • Washing machine, 3-5 loads a week
  • Dishwasher, up to 5 loads a week
  • Computer
  • Small air conditioner

Your ideal system: 3 kilowatts

Large home: 4+ people

🏤 👤 👤 👤 👤

What you can run:

  • Fridge
  • Halogen lights, 20+
  • Multiple HD TVs
  • Standby appliances
  • Washing machine, 5+ loads a week
  • Dishwasher, up to 5 loads a week
  • Dryer, 5+ loads a week
  • Computer
  • Large or multiple air conditioners
  • Pool pump

Your ideal system: 5 kilowatts

These estimates assume that the panels will be chosen from the higher end of the quality scale (higher power rating, more efficient) and that most of the devices and appliances in the home are energy-efficient models.

Solar companies will use formulas to find your energy needs in terms of kilowatt-hours (kWh), the same unit of measure the utility companies state on your bill, so that you can compare apples to apples. Without getting too mathematical here, they might find your daily kWh needs by summing a year's worth of kWh readings (from your bills) and dividing by 365. Then they figure how many panels at a certain power rating it will take to meet the daily need, given the hours of sunlight that hit the panels daily.

Does It All Depend on My Roof Size?

A collection of photovoltaic (PV) panels is called an array. You might picture the array on your rooftop, but you have other options. For example, mounting the panels on a ground framework in a corner of your property could be better for capturing sunlight and won't detract from the beauty of your roof.

Another option is to make the array serve double duty as a patio cover or carport roof. The variety of mounting locations and styles means your panels can follow the planes of your roof or be split between roof and pergola, between roof and yard, and so on.

Hours of sunlight per day can be maximized with tracking. This is when panels rotate/tilt to follow the sun. Tracking is an attractive option for arrays mounted on ground frameworks because it can extend the array's period of peak production by several hours per day.

Are All Solar Brands Alike?

As with most high-end devices rich in technology and materials—automobiles, 4K televisions, whizzbang computer systems—solar panels get their prices from a number of factors. Different brands combine the elements in different ways to distinguish themselves by power rating, durability, warranty, and of course price.

Factors that determine the cost of a solar panel:

  • Capacity (wattage)
  • Dimensions/size
  • Brand
  • Quality of materials
  • Durability/longevity or warranty period
  • Any certifications the panel might have

Choosing solar panels only by cost would be shortsighted because any money you save up front will probably cost you later in inefficiency and repairs. You'll be living with your brand choice for many years, so make it carefully. Higher-quality panels are more efficient and produce more electricity.

Luckily, solar companies have a lot of experience with different brands and are great at explaining the pros and cons of any choice. You won't be sent to the hardware store to pick out your own panels. Connect with a friendly local solar provider today!