Solar panels - are they worth it now?

javixeneize

I always wondered about installing solar panels at home but I heard it was mot worth it because it would take around 30 years to make it profitable 

with all the energy crisis going on, is it a better option to explore now? I assume at some point the prices of solar panels will go up as well though 

[Deleted User]

I have a 7kWp array that I installed last year. If generates about 5800kWhs a year of which I export 2200kWhs/year. 

I import less than 1000kWhs/year.

Based on a cost of £8000. I estimate that my array is saving me 3600 * 15p/kWh = £540 plus I gain £110 in export payments. Total income is therefore £650 per year. NB 15p/kWh is pretty conservative these days. 

Break even point at today’s prices is therefore 8000/650 = 12.3 years.

Solar panel prices have fallen dramatically over the past few years. You should aim to pay £1000 per 1kWp. My cost is slighter higher than that as I have an in roof rather on roof panel solution.

javixeneize

Interesting… is the proportion between solar panel energy and energy generated linear? It is, if I buy 5 solar panels, will it generate 5 times more energy and I will be payed 5 times more for the energy than if I have only one?

Thx 

Verdigris

No. You will still need an inverter to convert the DC current from the panels to 230V AC mains current, which will incur similar losses whether you have 5 or 1 panels. And there aren't FiT payment any more. You gain by using solar produced energy, rather than importing it, although you can enter into a SEG agreement with a supplier which will pay a small amount for exports. You'd need a smart meter for that.

lisyloo

Normal solar systems in the UK can't cover all our energy consumption.
This is because energy has to be used when generated and we need lighting/heating when there is no sun. 
People should also realise it's property specific e.g. the way the roof faces and how much sun it gets.
Also whether there is shading from a chimney.
They can't rely on general numbers for anything other than a ball park.

QrizB

javixeneize said:

Interesting… is the proportion between solar panel energy and energy generated linear? It is, if I buy 5 solar panels, will it generate 5 times more energy and I will be payed 5 times more for the energy than if I have only one?

Yes, more panels (of a given size) will generate more energy. Under standard conditions 1x 300 watt panel will generate 300 watts; 5x 300 watt panels will generate 1500 watts.

Here's a simple block diagram of a basic solar PV system. In this particular case it's a ~1kW system but it could be any size.

[Deleted User]

lisyloo said:

Normal solar systems in the UK can't cover all our energy consumption.
This is because energy has to be used when generated and we need lighting/heating when there is no sun. 
People should also realise it's property specific e.g. the way the roof faces and how much sun it gets.
Also whether there is shading from a chimney.
They can't rely on general numbers for anything other than a ball park.

You are 100% correct that location and property orientation are key factors, as is shading. Moreover, no solar system is 100% efficient: most have losses of c.20%. To a degree shading can be compensated for by the use of such things as SolarEdge.

You are also correct that solar PV alone will never meet our energy needs. Storage of surplus generation offers a way forward but the cost of batteries is still too high for most consumers. Moreover, when energy is needed most (ie, in the Winter) it cannot be guaranteed. My array generated over 150kWhs last December with daily output ranging from 10.3kWhs to 300Whs.

Snowclock

Just wondering how much this equation is changing with the threatened 50% rise in energy bills, next year.

I suppose China is feeling the rise in energy prices, also, so production costs of solar panels might also be rising, just to complicate the equation.

What's the best way of getting solar panels, just look for a local installer?

QrizB

Snowclock said:

Just wondering how much this equation is changing with the threatened 50% rise in energy bills, next year.

The threat (although it's almost a promise at this stage) is of a 50% rise in the Ofgem cap. What happens to energy bills remains to be seen.

I would be reluctant to make an investment with a 5-to-15-year payback period on the basis of the past five months of unusually high gas prices.

If you can comfortably afford solar panels at a more typical price-per-kWh, go for it; if prices remain high it will be a bonus. Even a 15-year payback period is a better return than you'll get in a savings account.

(All the usual caveats apply; in particular you're unlikely to realise much benefit if you sell, so you should be planning to stay in your current home for the duration.)

Reed_Richards

QrizB said:

Even a 15-year payback period is a better return than you'll get in a savings account.

With a savings account you get to keep your capital but under present circumstances its value will be gradually eroded because interest rates are lower than the rate of inflation.  However if you want to buy something, like solar panels or a yacht, you still have the money to do so.  If you spend your money on solar panels you have to wait years before you get it all back however thereafter you have the money to spend and, if you're lucky, you still have the income and the savings from your solar panels.  Or instead you can have a great time sailing around on your yacht.      

BikingBud

QrizB said:

Snowclock said:

Just wondering how much this equation is changing with the threatened 50% rise in energy bills, next year.

The threat (although it's almost a promise at this stage) is of a 50% rise in the Ofgem cap. What happens to energy bills remains to be seen.

I would be reluctant to make an investment with a 5-to-15-year payback period on the basis of the past five months of unusually high gas prices.

If you can comfortably afford solar panels at a more typical price-per-kWh, go for it; if prices remain high it will be a bonus. Even a 15-year payback period is a better return than you'll get in a savings account.

(All the usual caveats apply; in particular you're unlikely to realise much benefit if you sell, so you should be planning to stay in your current home for the duration.)

Is the general consensus that PV are something to be wary of when purchasing a house?

There will be some due diligence to ensure there are no burdens or financial ties but I would consider that panels could be more attractive than the new kitchen with £10k of marble worktops.