How Large a Solar Panel System Do I Need to Power a Home

The size of your solar plant depends on several factors, including the size of your house. Once determined, home solar experts like HomeScape then decide on the number of solar panels that will constitute your solar structure before actual installations. 

As mentioned, a home solar company with experience and expertise as vast as HomeScape’s, plays a crucial role in correct assessments. They offer guidance on how many kW solar plants are required to power your house and customise the right-fit home solar PV system for your energy requirements. However, you can also decide to do the calculation yourself.

Find Out How Many Solar Panels You Require For Your House

There is a basic formula for determining the size of a home solar plant. However, the math behind answering “How many solar panels are needed to make that plant?” isn’t a challenge because the details required to put into the formula are often readily available. The three factors considered in this formula are:

Annual Electricity Usage

Start by determining your current average electricity consumption for at least one year. You can find this information in your monthly electricity bills, and its measurement should be in kilowatt-hours (kWh).

Solar Panel Wattage

Remember that different types of solar panels generate varying watts of power, regardless of their similar look and working. Therefore, panel wattage tells you the electricity production capacity you can expect from a single panel in a solar array. 

Typically, panel wattage can be anywhere between 250 to 400 watts. Depending on your home solar requirements and budget constraints, you can go for higher or lower than the average 300 watts.

Production Ratio

Your home solar plant’s production ratio shows a correlation between the energy output (expressed in kWh) and its actual size (expressed in W). A solar system doesn’t always produce electricity equal to its total capacity. The ratio varies widely depending on hours of sunshine received, weather conditions, and pollution levels in the region, thus influencing the solar panel system requirements for a home.

A 10kW system, for example, may give 16kWh of electricity annually. So the production ratio here will be 1.6.

Time to Place It All Into the Formula

With the three aspects of the equation sorted out, use the following formula to calculate the number Of solar panels needed to run your home:

Number of panels = system size / production ratio / panel wattage

Lets take the following figures for the sake of calculation:

The number of panels = 6,000 kWh / 1.6 / 300 W

This finally solves the puzzle and gives an average of 10 to 15 solar panels. They can generate enough solar electricity to power a medium-sized house. 

Now you are ready to do your maths to determine how many kW solar plant is required to power your house.

An Alternative Method for Calculating Estimated Solar Use

Need an easier calculation to find out the number of solar panels required? Upon determining your annual electricity demand through your monthly utility bills, you can multiply it by the total hours of peak sunlight that your designated solar installation area will get. Divide this figure by the panel wattage to get your number of panels.

A peak Sun hour is when you get 1,000 watts/square metre of sunlight. Peak sun hours differ from your ‘total sunlight hours. For example, in several regions of India, you get 6-8 hours of daylight, out of which peak Sun hours are typically around 4.

How to Calculate the Area Required for Solar Panels for Home

It is quite easy to calculate the area required for your home solar. Here is the easy formula to find out what area of rooftop space you need for installing your number of solar panels.

The average size of solar panels over 300 wattage is 2m x 1m (6.5 ft. x 3.25 ft.), giving us an average area of 2 sq.m or 21.50 sq. ft. 

Area required for solar panels = total number of panels ✖ area occupied by one panel.

The above calculation of 15 panels gives the installation area requirement of 15 x 21.50 = 322.5 sq. ft.

However, in a real installation scenario, the installer will ensure some space and create multiple rows and columns of solar panels, especially for high-capacity systems. This is necessary to ensure ease of accessibility for performing solar cleaning and maintenance. Hence, you can assume a little over the area you get through this formula.

Factors Increasing Solar Panel System Requirements for Your Home

Even highly efficient solar panels require the right conditions and correct installation to work at their full potential. Your answer to “What kW solar plant is required to power a house” also depends on the following factors:

• Shadow: Your neighbourhood buildings, trees, and poles can cast a shadow on your solar panels. Shade on even a small part of a single solar panel can reduce the total energy generated by your entire solar array. Ensure placing your solar panels at a shadow-free location where they capture maximum sunlight.
• Orientation: Solar panels should face the sun, thus their orientation must be set towards the equator. By this understanding, solar panels should be south-facing in countries in the northern hemisphere, like India.
• Angle of inclination: The Sun’s position varies from summer to winter. Thus, the right angle of inclination from the surface (on which the panels are installed) is important to ensure maximum power generation of a solar system in all seasons.
• Dust and snow: A layer of snow or dust covering your solar panels prevents the sun rays from falling on the solar cells. Routine cleaning is necessary for optimum solar electricity production.

FAQs

Does the type of solar system affect the number of solar panels?

You can expect the number of solar panels to vary among the three home solar options – on-grid, off-grid and hybrid. On-grid systems may need the least number of solar panels to power your home, thanks to grid availability and zero battery requirements. Stand-alone, off-grid and hybrid systems will have more solar panels to ensure 24/7 power availability.

Can I Live Off Solar Power Alone?

A solar panel system can alone entirely run your home in an off-grid and even a hybrid solar framework. The availability of solar batteries is a great advantage with these types of solar systems. However, more solar panels are needed to generate ample power to power your home during sun hours and also charge batteries to create a power reserve for later use.

Is solar panel maintenance costly?

Your solar panels only need routine cleaning and periodic maintenance to stay in top shape. Also, a significant failure is unlikely as solar panels have no working parts.

Is there any warranty on solar panels?

Most solar companies can provide 25 years of warranty on solar panels. This covers you against panel replacements in case they suffer damage due to environmental conditions.