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What does 4kw of solar look like?

In my article a few weeks ago, I wrote about assumptions and the danger of them. Here at moleenergy we may well have fallen into this very trap. We are always referring to 4kW’s of solar PV for the Home, but we are often asked exactly what this means. So, what does it look like and why is it such a good idea?


Firstly, most homes have a single-phase supply. This is the electrical line that connects us to the national grid. When we use solar to generate electricity the parts that aren’t automatically consumed in the home go back along this line and are ‘exported’. Every region has an operator who is responsible for this line and how it can be used. Our DNO (District Network Operator) here in the South West is Western Power. They have restricted the amount of electricity that can be exported back along the line to 4kW. Hence most of the home systems we install are 4kW, as it is the default system size for the home.

But what is 4kW and what does it look like?


OK, bear with me here. A 4kW system will generate more than 4kWh’s (kW per hour/units) a day in sunny conditions. In fact, it will generate around 30kWh in these conditions during the whole day. Confused?


Don’t be. This is spread out over the day and as such a 4kW line will cope admirably with the solar PV electricity being exported. However, if you use a lot of energy in the day this will be consumed fully in your home. A point to note here however, is that even if you use all of it in your home you still get your full FIT (Feed in Tariff)! So, the more you use in the day, the better it is for your energy bill.

Let’s talk panels now. In years past, to get 4kW of solar PV you would have had to use around 20 panels, which meant that many homes didn’t have the room for them on the roof. Today however, with advancement of technology this has been reduced to 12-15 panels, which is a far smaller surface area and the systems are more efficient. Panels now produce an extra 145 Watts each compared to the older panels, which is why we need fewer panels to make up a total of 4kW. These panels are mainly black and very aesthetic in their appearance.

How much energy does a 4kW home solar PV system produce?


A typical 4kW solar home PV system in South West England will generate about 4,000kWh in total of electricity over the course of a year. A typical home in the UK uses between 4,000 and 5,000kWh per annum.


The more electricity you use during the day the more of your 4,000kWh solar PV units you will use and therefore the greater your bill saving. These systems are not only incredibly effective but also extremely reliable. They come with warranties up to 10 years for the inverter (the device which converts the sun’s rays into energy and puts it either into the home or back into the grid) and the panels are warranted for 20 years.  That’s better than most goods that you can buy including cars! 


Moleenergy case study

Martin Berryman, a farmer from Kingsbridge, South Devon, invested in his first solar PV system from moleenergy in 2012. Since then, the system has virtually paid for itself and Martin has seen the benefit of this technology. He has been very happy with the service, in fact he was so happy that he has commissioned another system from moleenergy! Read the full story on our website


Source Details

 David Stevenson, Director of Moleenergy

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