When switching from standard electricity to solar energy, your solar panel’s size is determined by one factor: How much solar power do I need? Finding an answer to this question requires reflection on your end goal, such as maximizing Return on Investment (ROI), reducing environmental pollution, minimizing spending, or even jumping onto the neighbor bandwagon.

The first step in determining how many solar panels your home needs is to calculate the kWh used at present. A kWh is a unit of energy used over time that is required to calculate the energy bill. A 6-12 month average of your household electricity bill is recommended to calculate a feasible range.

Cost of Solar Panel Systems

How many solar systems does your house require to eliminate the electricity bill? The cost of solar panels and the quantity required are determined by your average electricity usage (kWh) and the place you’re located.

Regular solar panels cost around 65 to 75 cents per watt. Solar panel systems from high-end manufacturers can cost as high as one to two dollars per watt. However, solar installation costs are decreasing rapidly, thanks to the growing demand and federal tax credits, thereby making it more reasonable to go green.

The Solar Energy Industries Association study highlighted that solar installation costs reduced by over 70% in the last ten years.

In any case, you’ll need to spend around $10,000 or more for solar equipment, depending on your home’s size. Installation might require additional costs of up to $10,000.

Factors Determining the Number of Solar Panels Your House Needs

Interestingly, the amount of solar panels needed for your house is not determined by the size of your house. A bigger home does not necessarily mean more energy consumption.

To understand how many solar panels your house needs, you need to find out the answers to the following;

  • The amount of energy your house uses: Find out the monthly kWh your house needs on your electricity bill.
  • The direction of your roof: If you are in the northern hemisphere, southern-facing homes are likely to receive more sunlight.
  • The average sunlight in your area: If you’re a citizen of the U.S., the southwest side gets more sunlight than the northeast, which receives sunlight along with rain and snow.
  • The amount of energy your solar panel can generate: Solar installers can help you find the answer.

How Many Solar Panels Do You Need_

Calculating the Number of Solar Panels Your House Needs

Step 1: Determine How Many Watts Your House Needs

See your latest electricity bill to find out your monthly kWh use. In most bills, the overall kWh of electricity you used will be mentioned at the bottom, along with the cost of electricity multiplied by that amount. You can calculate how much solar panel your house needs by multiplying your home’s hourly energy requirement by the peak sunlight hours and dividing that by the panel’s wattage.

For example, say your average kWh per month is 290. 290 kWh divided by 30 days (1 month) equals 9.66 kWh per day. However, an average American home uses 877 kWh per month, which could make the electricity bill cost around $115.

Step 2: See if the Roof of Your House is Southern-Facing

Every house is different and uses either more or less power than the average home. Some of the other factors determining a solar panel’s effectiveness are the climate of the place you live in, roof direction, and shade.

In case your roof is southern-facing with no tree blockage, you can proceed to Step 3. However, if your roof has a shade or your house does not face south, working with a solar installer can help you determine the best place to install solar panels on your home.

Step 3: How Many Hours of Sunlight Your Area Receives

The size of your solar system your house needs will be based on your electricity consumption and the climate in the area you’re living in.

You’ll need a smaller solar panel system if you live in a region that receives sunlight all year long.  However, you’ll need a larger system if your region experiences more cloudy days and you also have the winter months to consider.

Step 4: Determining the Best Solar Panel for Your House

Even if you know the type of solar panels you need, it won’t help if your roof cannot fit them. You’ll need to determine the efficiency of your solar panel system.

A solar panel’s efficiency means that your solar panel is either alright, good, or great at absorbing sunlight for generating power. Panels with higher efficiency imply you need fewer panels, thereby less square footage of roof space for energy production.

Once you find out the kWh size of the solar panel system you require, look for the average space a low, medium, or high-efficiency panel will require on the roof of your house. In case you have extra room for installing your solar panel system, it might make sense to buy panels with low efficiency. This is because they are reasonable compared to the panels offering higher efficiency and can produce the same amount of electricity.

Determining the efficiency-level of your solar panel depends on the amount of space you have on your roof.

The Bottom Line

Solar panels will generate electricity while the sun is shining on top of your roof. To increase your savings, you’ll need to use the electricity you produce and lower your export amount. This is because if most of your consumption is at night, you’re not going to benefit more, irrespective of making enough energy to cover your consumption.

Clever design can help resolve this problem. For example, installing solar panel systems on the western side will help increase energy production during the afternoon, thereby helping families run an air conditioner or other electrical appliances later in the day.

Other ways to solve this include load shifting, which means using more electricity during the day than at nighttime. This could include washing machines, microwaves, pool cleaners, or dishwashers while output from the solar panel system is at its highest.

NMWE Free Quote

Pin It on Pinterest