Likely kWh per sq ft from Solar Panels

Solar panels are often spoken about in kW terms, for example the average household needs around a 3-4kW system to produce sufficient electricity. A 3kW system will need to be about 226 sq ft. That may sound huge but it is only 15ftX15ft, which will easily fit on most roof spaces. Each individual solar panel in that system will probably be around 17 sq ft and have an optimal output of around 345W. This means that each of your solar panels will give an average output of 20W per sq ft. Over a year this will equate to your 3kW system outputting around 121 kWh per sq ft, or 2,550 kWh in total.

To see what kWhs mean for you in terms of running appliances and costs compared to traditional energy suppliers see here.



Average solar panel output kwh

The output of solar panels will depend on the size of the system you have, its efficiency and the direction the panels face. To get the most from your solar panels they should ideally be facing south and placed at a 30°-50° angle. The table below shows the average figures for various sizes of solar panel system. The highlighted column shows the estimated annual output for each size system in kWhs. The average household in the UK uses up to 5,000 kWhs of electricity each year.

Approximate Roof Space:

Typical System Size:
Estimated Cost (£):

Estimated Annual Output:

CO2 saved over 25 years (tonnes):

Estimated First Year Return:
Profit Over 20 years:
14 sq m
2kW
3,000-4,000
1,700kWh
20
£368
£3,800
21 sq m
3kW
4,000-6,000
2,550kWh
30
£534
£5,635
28 sq m
4kW
6,000-8,000
3,400kWh
40
£700
£6,750





Solar panels cost per square foot

Is is difficult to say how much solar panels cost per sq ft because costs are determined on the size, type and quality of the solar panels. However, in order to demonstrate the cost per sq ft we can use some average figures to work out an estimate. It is important to remember that the solar panel cost figures we use include all installation, additional equipment and warranty certificate costs.

A 2kW system will cover about 150 sq ft and a mid range cost would be £2,775 meaning the system would cost £18.50 per sq ft. Using the same formula a 3kW system, covering 226 sq ft, costing £ £5,000 would work out at £22.12 per sq ft. Finally, a 4kW system, the biggest that a residential property would need, covering 301 sq ft and costing £7,000 to install would equate to £23.26 per sq ft.



Size of solar panels per kwh

Solar panels absorb light and turn it instantly into electricity. Therefore, it makes sense that the more surface area your solar system has, the more sun they can absorb and the more electricity they can make! The average solar panel system will produce between 9-11 kWhs per sq ft, every year. This means if you have a 1kW/86 sq ft system you will be able to use about 850 kWhs of electricity per year. Whereas, if you have a 4kW/301 sq ft system you will benefit from around 3,400 kWhs of electricity from your panels each year.

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