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The Solar Energy Portal

How many Solar Panels are needed to power a House?

The installation of renewable energy are becoming more and more important when it comes to reforms at home.

One of the most demanded works in homes is the installation of solar panels but,how many solar panels are needed to power a house? We tell you all the keys.

The first of all is to ask ourselves why we want the photovoltaic panels. doSave energy? Sell ​​it? doMinimize our carbon footprint?

All these questions will determine the number plates that we will install

What Factors do I have to take into account to Install Solar Panels?

The main factors you have to take into account are:

1. Meters that your Roof has for the Installation of the Panels

The solar panels They usually occupy a two square meters of surface. This determines the number of panels that are installed and also their power.

That is, if you have less meters your photovoltaic panels They will need to be more powerful. In this way, you can complement the lack of space.

If your roof is somewhat smaller and some high power plates do not fit within your budget, there are also other alternatives.

For example, if you have more land, you can install them on it. There is also talk of shared dashboards with other nearby buildings.

This would serve to counteract the lack of space of a building on another nearby roof that does not take advantage of yours. This is done more in parking lots.

2. Climate of the Area in which you live and Hours of Light that you have

There are several measures to obtain the maximum performance of your photovoltaic installation.

The panel orientation and the geographic situation from your living place There are two determining factors.

On the one hand, south facing solar panels produce more energy. Specifically, a 54% more than those facing north.

On the other hand, the solar irradiation in the different areas of Spain it varies. An installation in the south can yield up to 27% more than one in the north.

For example, one facility common in Seville of 3000 kWh per year may need 10 panels. However, the same installation in Asturias would need two panels plus.

Another factor to take into account is the solar panel tilt. This tilt varies depending on the angle of the sun. It is usually around 10º for summer and 50º for winter.

Change the tilt constantly tends to be complicated. Therefore, a global approximation of 34.5º makes energy production profitable.

3. Energy that your Home consumes

It is the most important aspect when calculate how many solar panels are needed to power a house.

Of course, it is necessary to calculate taking into account the hours that will receive solar radiation. If possible, this consumption could even be discriminated during daylight hours.

This is because the same energy use is not made at night than during the day. Nor is the same use made in summer as in winter.

For this reason, experts recommend add 25% to the total energy consumed. In this way you could reach 100% of the use of clean energy generated on your roof.

In order to know the average consumption, check the electricity bill. It will show the kWh (kWatios used per hour). Even though this consumption It also depends on the month you look at.

Therefore, the ideal is to make an average with the consumption of all the months of the year. to that consumption we add the surplus which we have already talked about.

Once we have the annual consumptionall we have to do is divide by 365. Thus, we will obtain the daily consumption. Then, we divide the obtained by 24. The result will be the consumption per hour.

Once this is done, we would already know the kWh we need in our solar panels.

4. Power of our Panels

The panel power may vary. Depends on the amount of panels that we want to put and also its use.

it won’t be the same power for a house you want self-consumption of energy that for another that only needs the Energy to heat water.

This power is usually around 250W and 300W. However, there are more and more powerful solar panels. One of these newer home solar panels can reach up to 650W.

How many Solar Panels do I need?

Source: Windmar

We already know the factors that influence the location of the panels. Also the energy we need to obtain from our photovoltaic installation. Now, we only have to know how many solar panels are needed to power a house.

As we have seen, it all depends on the location. However, we can make a rough estimate of the average number of households.

According to him IDAEthe average consumption of Spanish households is 8000kWh/year.

For this calculation we will take plates of 320W. These are usually one of the cheaper options.

We will take the case of Murcia, where the rate of Peak Sun Hours It is 1800 HSP.

So the power that the house needs would be: House Consumption/HSP= 4,400 Watt.

Now divide the total power between panel power: 4,400/320=13.75

Therefore we need 13.75 solar panels. That is, between 13 or 14.

In general, if your consumption is up to 2000 kWh you will need between 2 and 4 panels. If your energy consumption is between 2000 and 5000 kWh, you will need between 4 and 7 panels.

From 5000 kWhthe panels you will need they will be from 7 onwards.

Or, what is the same, if you pay €50 on your lu billz, you need between 3 and 4 panels. If the amount of your bill is between €50 and €100, there are 6 panels. If your bill is more than €100, you need from 7 onwards.

Once we have this, all we have to do is adapt it to the meters that we have on our roof.

If we have less space, a few solar panels of higher power. For example, yes we double the power of the panels, the number of plates we will need will be half.