How Many Solar Panels Do I Need?


Jack Ayre

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With public awareness of the detrimental effects the widespread use of fossil fuels is having on the environment on the rise, many people are looking for alternatives. One of the most popular solutions is solar energy. If you’re thinking of installing solar panels, you may ask, how many solar panels do I need?

The number of solar panels needed to fulfil a household’s energy requirements depends on several factors. These include the household’s current energy usage, the amount of sunlight the area gets, the roof’s orientation plus the solar panels’ size and efficiency.

Read on to learn more about how to determine the number of solar panels you need to install and the significant advantages of installing solar panels on your property.

Factors That Affect the Number of Solar Panels You Need

When determining the number of solar panels you’ll need to install to meet your home’s energy requirements, there are several factors to consider, including.

Your Current Energy Usage

First of all, you need to know how much energy your home uses. You can find this information through your electricity bills.

Your electricity bills, usually issued every 30 days or quarterly will typically mention the number of kilowatt hours you’ve used over a fixed period. To calculate your daily kilowatt hour usage, divide the kilowatt hours used by the number of days. 

Some companies don’t quote the number of kilowatt hours used on their bills. In this case, you can figure it out by subtracting the beginning meter reading from the ending meter reading. 

Divide that figure by the number of days between both readings to calculate your average daily energy needs.

The figure you calculate is the number of kilowatt hours you need your solar panel system to produce each day to fulfil your energy needs. 

The Level of Sunlight in Your Area

Another essential factor to keep in mind is the amount of peak sunlight hours your solar panels will receive. How much sunlight your panels get will directly affect the energy you can expect them to produce, and in turn, how many panels you need.

For example, those who live in the South of England are likely to get many more peak sunlight hours than residents of the Scottish Highlands. Therefore, the former will need fewer solar panels than the latter to satisfy their homes’ electricity requirements.

To calculate how many watts your panels will need to produce per hour, divide your home’s hourly energy requirements in watts by the average number of peak sunlight hours your home gets per day.

Note that the climate in your area isn’t the only thing that affects the amount of sunlight your solar panels will receive. Your roof’s angle, orientation, and shading will also play a big part in determining it.

If your roof is set up in a way that allows it to fully capitalise on the sunlight, you’ll need fewer solar panels than if part of your roof is shaded.

Solar Panel Size

The size of the solar panels you’re installing is also a factor that decides how many of them you’ll require. 

For residential units, the typical area of a solar panel is 1.64 square metres. Such solar panels usually consist of 60 cells. On the other hand, commercial solar panels are composed of 72 cells and have an average area of 2 square metres.

Get in touch with ESE Solar to schedule an appointment with our experts. They’ll visit your home and measure your roof’s area to advise on how many solar panels you can install safely. 

Solar Panel Efficiency

Another factor that determines the number of solar panels you’ll need to install is how efficient each panel is in producing energy. The more efficient solar panels are, the greater their ability to convert sunlight into electricity per square foot.

A solar panel’s efficiency relies heavily on its design and quality. You should go for solar panels that don’t have gridlines as these gridlines reduce the panels’ active surface area, and are less durable.

Furthermore, you shouldn’t prioritise cost over panel quality. Solar panels made from low-quality materials will corrode and crack over time. In turn, their efficiency will take a major hit.

Step-By-Step Instructions: How to Calculate How Many Solar Panels You Need

In this section, we’ll take you through the exact steps you should go through to calculate the number of solar panels you’ll need to power your home.

We’ll outline the equation you should use and outline how to do so.

Here’s the equation: 

Number of Solar Panels Needed = { (Annual Household kWh consumption x 1000) / (Average Daily Peak Sunlight Hours x 365) } / Wattage Per Solar Panel

To illustrate how you can use this equation, let’s make the following assumptions:

  • Annual Household kWh consumption: 11,000 kWh
  • Average Daily Peak Sunlight Hours: 5 hours 
  • Wattage Per Solar Panel: 400 W

First, multiply the annual household kWh consumption by 1000

11,000 x 1,000 = 11,000,000

Next, multiply the average daily peak sunlight hours by 365 and divide the figure from the first step by the answer.

5 x 365 = 1825

11,000,000 / 1825 = 6,027.4

Take this number and divide it by the wattage per solar panel.

6,027.4 / 400 = 15.068

Round the figure up to the nearest whole number.

Based on the calculations we can conclude that a household that uses 11,000 kWh of electricity per year and gets 5 hours of daily peak sunlight hours on average needs 16 solar panels with a 400 W output to cover its energy requirements. 

Advantages of Solar Panels

You may wonder if installing a solar panel system for your home is worth it in the first place. The answer is that it is for sure.

Solar panels come with plenty of advantages, here are the most significant ones:

They Reduce Your Electricity Bills

The cost of electricity has risen substantially over the past couple of years. Therefore, many homeowners are looking for ways other than the traditional electricity grid to cover their energy requirements.

Solar panels are significantly cheaper in the long run than the traditional grid. Some may argue that their high installation costs negate this. However, this argument is no longer valid since solar panel installation costs have dropped drastically as technology has developed.

You may ask exactly how much you can save per year with solar panels. As per the Energy Saving Trust, those who have a 4.2 kW solar panel system installed, typically pay £210 to £514 less in electricity bills annually.

Furthermore, you can take advantage of the Smart Export Guarantee. The SEG initiative allows you to get paid for pumping energy back into the national grid, ensuring any excess electricity your solar panels produce won’t go to waste.

They Make You Eligible For Tax Breaks

In addition to the smart export guarantee, the UK government is attempting to get more home and business owners to use solar energy by offering tax incentives.

For homeowners, the government has reduced the VAT applied to solar panel installation to 0%. This reduced tax is valid until 31 March 2027.

As for business owners, there’s a lot to be gained from powering your commercial buildings using solar panels. For every £1 you invest in solar panels, you can save up to 25p in taxes. These tax savings can add up and boost your bottom line substantially. 

They Raise Your Property Value

Not only does installing solar panels lower your electricity bills, but it can also raise your home’s property value. As a result, you can cash in significantly more when the time comes to sell your house.

You may see this to be counterintuitive since solar panels don’t exactly enhance your home’s aesthetic. However, having solar panels installed can increase your property’s value by up to 14%.

With the rising prices of property and living expenses, making sure to put yourself in the best financial position possible is never a bad idea.  


1. What’s the difference between solar PV and solar thermal panels?

Both solar PV and solar thermal panels achieve the same results. They convert energy from sunlight into electrical energy, the difference between being in the way they work.

Solar PV panels serve their purpose by using the photoelectric effect. It involves passing sunlight through photovoltaic cells made out of semiconductors and converting it into electricity.

On the other hand, solar thermal panels use a heat transfer medium, such as water, to serve their function. They’re also typically cheaper to install than solar PV panels.

2. Do you need planning permission for solar panels?

Solar panels are usually considered Permitted Development so planning permission is not usually required. The situation changes if the property is in a conservation area or is a Listed Building, in which case planning approval will be required. 

3. Do solar panels reduce your carbon footprint?

Your carbon footprint when using solar panels as your primary energy source is significantly lower than with fossil fuels like oil, coal, and natural gas.

This is because solar panels operate with zero emissions. Some may argue that the production of the solar panels themselves harms the environment. However, solar panel production produces less carbon dioxide and uses less materials. 

Additionally, solar panels can operate for over 20 years, which makes them more sustainable than other energy solutions.

4. Do solar panels come with a warranty?

Yes, most solar panel manufacturers offer a 20+ year warranty with their products. The warranty’s level of coverage will vary from one manufacturer to the next.  

How Can We at ESE Solar Help You?

If you want to install a solar panel system on your property, there are many ways that ESE Solar can help you.

Contact our team to schedule a consultation. We’ll send our licensed experts to your home to take measurements and advise on how many solar panels you need.

Furthermore, we offer 0% VAT installation, and all our products come with a full-coverage warranty. We also have a price match guarantee to reassure you that you’re always getting the best bargain when you deal with us.

How Many Solar Panels Do I Need Conclusion

If you’re looking to take steps towards becoming a more environmentally responsible individual, you may be considering solar panels as an alternative to fossil fuels to fulfil your energy needs, and therefore wondering how many solar panels you need?

To answer this question, you should keep several factors in mind. Firstly, you need to know the amount of energy your home uses on average. Additionally, you should consider the climate in your area and gauge how much sunlight your panels will get.

Furthermore, the size and efficiency of the panels you’ll install directly affect the number of panels you’ll need to cover your household’s electricity needs.

Get in touch with ESE Solar and schedule a visit to start your journey towards sustainable energy. Rest assured that you’ll be in good hands!  


On This Page

Cut your electricity bills

Generate your own electricity with a solar PV system

With a new solar setup, including a solar battery, you can drastically reduce your electricity bill


Cut electricity bills

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Sustainable home

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Born in North West England, Jack kicked off his career in the insurance arena, dealing with claims for three years. Always up for a challenge, Jack leapt out of his comfort zone and embarked upon 5 years of excitement with the military.

Working for the Ministry of Defence, Jack specialised in counter-terrorism which took him to places such as Dubai, Oman, Iraq, Norway and Bahrain. During this period he worked with various Governments implementing strategic operations to prevent terrorism.

After travelling around various countries Jack increasingly came across various forms of solar from large solar farms to domestic solar panels. From here Jack took a keen interest in all things solar and started reading about the technological capabilities with a view to entering the industry after his career in the Ministry of Defence.

Once home after 5 fruitful years, Jack had 3 months leave in which he immersed himself in a solar crash course and got applying for jobs within the solar sector. He came across ESE Solar, a long-established forward-thinking company whose head office was only a stone’s throw away from him. He picked up the phone to see if there were any vacancies and within a week had a successful interview and obtained a full-time job, starting in the technical team.

Within the first few months, Jack onboarded in various online courses during work and social hours to speed up his knowledge of all things solar. Due to his strong work ethic and thirst for knowledge Jack was promoted to Head of Technical at ESE Solar. He currently leads the team and oversees the product development of new technologies within the company alongside assisting where necessary on their maintenance department.

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