Should You Install Solar Panels on Your North Facing Roof?

Written by Tok Charles | 31 Oct 2023

Everyone knows that you can’t put solar panels on a north facing roof…. or can you?

With electricity prices rising, north facing solar panels are now often worth the money.

Long ago, when the year was 2010, electricity was cheaper than it is now and solar panels were way more expensive.

Installing solar just about made financial sense on a south facing roof. But installing on a north facing roof made absolutely no sense.

That’s because a north facing solar system typically produces about 56% of the output of a south facing system.

Since 2010, the cost of electricity has risen from 11p per kilowatt hour to over 30p per kilowatt hour. That’s almost a three-fold increase.

Source: UK Gov Average unit costs and fixed costs for electricity for UK regions (QEP 2.2.4)

Meanwhile, solar panel prices are now less than half their 2010 price and their efficiency has almost doubled (that’s a four-fold increase in kW per £).

Given these changing dynamics, can the past “lack of recommendation” for North facing solar panels still be justified?

This week we ran some numbers to find out.

Taking as an example a standard 10 panel domestic system (4.3kWp), this is what we found:

a north facing system will pay for itself in 12 years: not bad given that it will last 25 years (by comparison a south facing system will pay for itself in 7 years);
the average “lifetime” cost of solar electricity generated is 12.2p per kWh - way below the average cost from the National Grid (28p to 33p per kWh, depending on the contract with your supplier);
if you install panels on both sides of your roof (i.e. on the north and on the south side, or on say the north-east facing roof and south-west facing roof), you will typically get a payback time of 10 years.

Here is a summary of the numbers:

	10 Panels facing North	10 Panels facing South	10 Panels facing East or West	5 Panels facing North and 5 facing South
Output per year (kWh)	2322	4231	3367	3277
Expected % of solar output used on site	52%	37%	42%	44%
Savings and Income (per annum)
Savings	£398	£517	£467	£476
Export income	£167	£400	£293	£275
Total Savings and Income	£565	£917	£760	£751
Amount of time taken to pay back initial investment	12 years	7 years	9 years	10 years
Total expected output over the 25 year life of the system (kWh)	54,700	99,670	79,310	77,180
Lifetime cost per kWh of solar electricity generated	12.2p	6.7p	8.4p	9.1p
Current grid cost per kWh of electricity	~ 30p / kWh	~ 30p / kWh	~ 30p / kWh	~ 30p / kWh

In conclusion, north facing solar panels are now worth the money! Obviously you should first fill up your viable south or east / west facing roofs before installing on a north facing roof.

If you’ve already filled up your south facing roof, or if you are new to solar and want to “max out” all available roof space to generate as much electricity as possible, it is clear from our analysis that topping up your system by filling up a decent sized (8 panels plus) north facing roof (or north-east facing roof, or north-west facing roof), now makes perfect financial sense.

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