A key question every potential customer asks themselves is about how much power their solar panels can generate.

It’s a natural question. You’re planning to invest significantly in generating renewable energy so you want to know how much energy the solar panels will produce.

This page will seek to answer that question. We discuss:

  1. Solar panel output
  2. Solar system output
  3. What influences solar panel output
  4. How much power do you need?
  5. How much space will my solar panels require?
  6. How can I track how much power I generate?

Solar panel output

Solar panel output is measured in watts (w) and each solar panel is rated to a particular output. For example, our solar panels are rated from 5w up to 335w each.

The LG Solar Panel 335W Mono Neon2 A5 is one of our most powerful solar panels and can generate 335w. Considering it only measures 1,016mm x 1,686mm, that’s a very effective panel!

Conversely, a smaller solar panel for cars or vans, like the 6v 5w Monocrystalline Solar Panel generates just 5w. Considering it only measures 186mm x 251mm that’s not bad but it couldn’t power a house!

The higher the wattage, the more power that panel can produce. Newer solar panels can produce higher wattages but can also be more efficient, i.e., more of the energy they generate can be turned into usable power.

Want Help Installing an Off-grid Solar Power System?

We offer a nationwide off-grid installation service. Discuss your off-grid power requirements with Sunstore today!

Request a Quote

Solar system output

So now we know solar panels are rated at a particular wattage, how can we calculate how much power a solar power system using several solar panels can generate?

It’s actually very straightforward!

Multiply the solar panel wattage by the number of sunlight hours in a day and then multiply that by the number of solar panels you have.

For example:

Using the LG Solar Panel 335W Mono Neon2 A5 as our sample solar panel the calculation would be: 335 x daylight hours x number of panels.

If you had 5 hours of daylight per day and had 8 panels, your calculation would be, 335 x 5 x 8 = 13,400w or 13.4kW. (1 kW is 1000 w).

To find out how many hours of sunlight per day you get, you can use a website like this one that provides an average of daylight hours per month. Remember, this is Britain, so daylight hours and actual sunlight can vary!

What influences solar panel output

Solar panel output can be influenced by several factors. They include the capacity of the panel, it’s efficiency, the materials it is made from and the direction your roof faces.

Other factors such as weather and any trees or shade that may block the sun can also influence how much energy you produce.

  • Solar panel capacity – As discussed above, solar panels are capable of generating different amounts of energy expressed in watts
  • Solar panel efficiency – There is no such thing as 100% efficiency in solar panels. Most new panels are between 20-50% efficient
  • Solar panel materials – Different panels are made using different materials. Monocrystalline panels are more expensive but more efficient. Polycrystalline panels are slightly less efficient but cheaper to buy
  • Roof facing – The ideal roof angle is 30 degrees and south facing as it would receive the most direct sunlight. Any variation on that and the output will drop accordingly
  • Other factors – Trees, tall buildings and other elements that can shade solar panels during the day can reduce the amount of power they generate

Our Most Popular Off-grid Solar Kits for Homes

How much power do you need from your solar panels?

The amount of power you need to generate depends on where you’re installing your solar panels and how much electricity you use.

Energy usage is measured in kilowatt hours (kWh).

You can find out how much energy you need using your electricity bill or smart meter. It should give you average daily, weekly or monthly usage. On average, a British home uses around 3,800kWh per year of electricity, just over 10kWh per day.

If you were to estimate that there were 5 hours of sunlight on the average day in your region, this is just an example, then you’d need a 2kw system i.e. 2kw x 5 hours = 10kWh per day.

Therefore, your solar panel system should aim to generate at least this amount. Again, check your electricity bill for a more accurate estimate or contact our team.

How much space will my solar panels require?

The answer to this question depends on your answers to the above questions. The more energy you need to generate, the more panels you’ll need. The more panels you use, the more space they require.

You also need to factor in the capacity of each panel. For example, you would need more 250w solar panels to generate 2kw than you would 335w panels. Each panel measures roughly the same but their ability to deliver enough energy for your needs differs.

As an example, a 2kw system would require 8 x 250W panels. If each panel is roughly 1.6m x 1m you would need 12.8m2 on your roof to house them.

The same 2kw system with 335W solar panels would require 6 panels in total. These panel are slightly larger at 1.67m x 1m but would result in a smaller footprint of 10m2 due to the reduced number of solar panels required.

Remember this is an average. Our team will be able to give you exact figures on request.

How can I track how much power I generate?

Most solar panel systems will come with a meter that shows how much energy is being generated at any given time. Some systems can also provide an online monitoring tool you can access via your phone or computer.

Much will depend on the system you buy and how much you want to monitor. As solar panel systems are practically zero maintenance, not everyone wants to monitor output so these meters can be optional.

As you can see, while there is a lot to designing a solar panel system, once you break it down, it is actually quite straightforward.

If you’re interested in going solar and want more specific information about your solar panel requirements, contact our sales team on (01903) 21 31 41. We would be happy to help!

Request a Quote

Fill in the form below for a free no-obligation quote. Our off-grid installation service is available nationwide and starts from £360.

    The following optional details will allow us to provide you with a more accurate quote.


    Your address (optional):

    Solar panel mounting (optional):

    List items to be powered (optional):

    Usage (optional):

    Any existing grid connection (optional):

    Upload an image or drawing (optional):

    For more information and your personal quote please call or email:

    01903 21 31 41

    [email protected]

    Print Friendly, PDF & Email