How many solar panels do I need?
If you want to know how many solar panels you need to power your home, the answer will depend on a few important factors.
It’s estimated that the average one-bedroom house needs six solar panels, while a typical three-bedroom house requires 10 panels.
However, the number of panels required will also depend on the size and efficiency of the panels themselves and there are actually quite a few different types of solar panels that vary in cost depending on the style and technology.
What type of Solar PV Panels will you need?
The most common solar panel installed in UK homes is Photovoltaic (Solar PV) which is made from silicon, creating a semiconducting material that perfectly produces an electric field when the sun is shining on them. These are very effective for generating energy which will save you money on your electricity bill. Installing solar panels depends on the size of the system and can usually be installed within one day.
It’s worth knowing that there are different types of Solar PV panels and their performance will vary.
The most common types are:
- Monocrystalline
- Polycrystalline
- Amorphous
Expect that your solar panel installer will supply a Crystalline product as they provide the best performance and ultimately have a longer life expectancy.
Read more about how solar panels work here
How many solar panels will my home need?
Smaller homes might need a 1kW system, with roof space for 8+ m2 of solar panels, while higher demand can be met with a 4kW system, but that would need 25+ m2 of space on your roof.
The average size of a solar panel is 1.6 m2 and a survey of your property would be recommended to establish how many solar panels your house would need.
The more solar panels you have installed, the more energy they’ll be able to generate for your home.
The number of solar panels you will need will depend on your energy usage, the number of people in your home and the size of your property.
You also need to consider that many homes have electric cars and home battery storage. These homes will consume more energy.
How much Solar Power does your home need?
The size of your home and the number of appliances will determine how much energy you need to generate.
A handy tip is to look at your bills to see how many kw’s your home consumes annually. Your energy provider will give you an estimate on your bills and more modern providers that allow you to pay for what you use will immediately notify you of your recent energy consumption.
You can then multiply this by 12 to get an annual projection.
How much solar power can I generate?
A solar panel installer can take into account all the relevant factors, such as your roof size, shade patterns, roof pitch and local weather conditions. With their help, you can determine exactly how many solar panels you need to power your home efficiently.
Ultimately, it will be the space available that will determine how much power you can generate but you will also need to consider the orientation of the roof and geographical location and type of solar panel.
The manufacturer will be able to confirm the Wp (power in watts) which would have been tested in optimal conditions. But for a typical example;
If you’re a family of 4 (2 adults and 2 children) living in a semi-detached 3-bedroomed house in Portsmouth with a south-facing, 30-degree roof pitch with no shading :
It would be recommended to install 10 solar panels that will save you around £1200 per/year on electricity bills.
*This typical example is based on an average-sized semi-detached 3-bedroomed property – 10x 370watts = 3.70kW peak, tied into a 3.68jW inverter in optimal conditions.
What kind of condition does my roof need to be?
For the UK market, it is generally recommended to install solar panels with a roof pitch between 30-40°, as this angle provides optimal performance. However, it’s important to note that solar panels can still generate electricity effectively even if the angle of the roof falls outside of this range.
In the UK, where sunlight conditions may vary, it is worth mentioning that solar panels can still absorb sunlight even when installed horizontally. However, it is important to consider that solar panels positioned at an angle less than 12º may face challenges with self-cleaning. As dirt accumulates on the panels, their effectiveness can decrease over time.
How big are solar panels and how much space is needed?
One thing to note is the difference between how much space you have available and how many panels you need to cover your energy bills. The recommended amount of solar panels needed for a family of 4 is 10. So your roof will need a space of roughly 26 m2. Internally you would need space for the solar inverter and a battery pack.
Your roof space needs to be in reasonable condition with standard panels weighing around 23kg. A good installer will assess the space before commencing with the work
What are the risks and disturbances?
Fortunately, installing solar panels is a relatively painless process. As long as you get quotes from 3 MCS registered installers, you know the advice you will be offered is in line with the Government’s recommendation. Solar panel warranties are also pretty good with manufacturers covering all the appliances. The UK government is also discussing the creation of a Guarantee Scheme and facilitating an approved list of
suppliers.
