What do solar panels yield?

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What do solar panels produce?

First of all you want to know what solar panels produce. Besides the rating of the panels in watt-peak (Wp), a number of things affect their yield. For instance:

• The time of year
  Which months produce the most? It differs across the year, but the yield is highest in spring. May to July in particular have plenty of hours of sun while it is not yet too warm.
  
  
• The type of roof
  The yield also depends on the roof and its surroundings. A sloping roof facing east or west gives a good yield, but a roof facing south catches the most sun and therefore produces most. It also helps if there is as little shade from trees or buildings as possible. Want to know whether your roof is suitable? Then read our blog "is my roof suitable for solar panels" .
  
  
• The angle
  Panels at an angle of about 35 degrees generally generate the most electricity. A flat roof can still give a high yield: there we mount the panels on a frame for the best result, at an angle of about 15 degrees to avoid shading and reduce the effect of the wind.
  
  
• Types of panel
  Solar panels come in many shapes and sizes. The yield depends among other things on the watt-peak per panel, on the quality and on the number of panels. We think it matters that all of this is matched to your own situation.

Working out the yield of solar panels

How much power will your system generate? To give you an idea, we have worked through an example. Bear in mind that the exact yield differs per type of panel.

A worked example

We assume one panel is rated at 430 Wp on average. Nine panels of 430 Wp therefore come to 9 x 430 = 3,870 Wp.

The Netherlands is not always sunny, so panels do not produce electricity (in kWh) at their peak rating all the time. That is why we use a usable capacity of 85% in the sum, which means about 0.85 kWh of electricity per 1 Wp. For nine panels the usable capacity works out at 0.85 x 3,870 = 3,290 kWh a year.

The capacity also depends on the outside factors mentioned above, of course.

If you choose panels with an Enphase, SMA or SolarEdge inverter, the app shows exactly what your panels produce each day.

Cut your energy costs

Now that you have an idea of the cost and the yield, you can see how much you stand to save on your energy bill, especially with prices as high as they are. That saving is what pays the system back. If you have asked us for a quote, the payback time is part of it. On average it is about five or six years.

You can also still benefit from net metering. If your panels generate more than you use, you can feed the surplus back to your energy supplier. You are paid for it, or it is set off against the power you used.

It is also good to know that you get part of the cost back from the tax office, namely the VAT. We arrange that for you, so you need not think about it. From 1 January 2023 the government intends to bring the VAT on solar panels down to 0%.

Our tip: ask your local council as well whether any subsidies or contributions are available.

More energy and less CO2 thanks to solar panels

Solar panels are not only good for your energy bill; they are good for the environment too. How so? Grey electricity usually comes from burning fossil fuels, which releases CO2 and harms the climate. Generating solar energy is therefore a good way to cut this country's emissions. Did you know that every kWh you generate saves about 0.46 kilos of CO2?

Solar panels are not (yet) entirely free of CO2, because making and shipping them releases some. Happily, more and more companies are looking for ways to produce panels without emissions, and without other materials that harm the environment such as lead, fluorine and PFAS.