Are Solar Panels a good investment?

sazzlelondon

We’ve been quoted for solar PV panels that should give us more energy than we use on average per year. But I worry about whether the projections can be trusted. Do solar panels really save you money in the long term? With rising gas prices we are even considering installing an electric water cylinder to be powered by the panels. But I can’t help thinking, if save money was that easy why haven’t more people gone solar? Any thoughts on whether solar really does create long term savings?

Reed_Richards

The trouble with solar panels is that they give you electricity at a time when you would not normally be using much electricity.  You won't get nearly so much in winter and obviously not when it's dark.  You need special permission to export at power levels more than 3.68 kW.  And at current electricity prices there is a huge difference between what you will be paid for electricity you export compared to what you pay for electricity you import.

I myself have solar panels and a storage battery.  The battery helps to match solar supply to electricity demand but considered opinion is that batteries are not economic.  For me it's as much about being green as expecting savings.

sazzlelondon

Reed_Richards said:

The trouble with solar panels is that they give you electricity at a time when you would not normally be using much electricity.  You won't get nearly so much in winter and obviously not when it's dark.  You need special permission to export at power levels more than 3.68 kW.  And at current electricity prices there is a huge difference between what you will be paid for electricity you export compared to what you pay for electricity you import.

I myself have solar panels and a storage battery.  The battery helps to match solar supply to electricity demand but considered opinion is that batteries are not economic.  For me it's as much about being green as expecting savings.

Thanks - a battery in is the quote. I dont think we’ll export much. This is for my elderly parents house and so they are thinking primarily about saving money, green of course being a bonus. Sounds like its only worthwhile if both factors are equally important?

Reed_Richards

You (or rather your parents) will export lots, or generate a lot of power that could be exported if export were not limited (without special permission).  During the summer months they'll likely be able to charge the battery in the morning on a sunny day.  But the current with which the battery can be charged is limited so they'll export most of the excess.  Then they can run the immersion heater to re-heat the hot water tank for an hour or two but they'll probably have more power than the 3 kW needed to do this, most of which will get exported.  Then it's maybe 2 pm and they will export most of the electricity generated for the rest of the afternoon.  It's different in winter but they will generate very much less solar power then.     

sazzlelondon

Reed_Richards said:

You (or rather your parents) will export lots, or generate a lot of power that could be exported if export were not limited (without special permission).  During the summer months they'll likely be able to charge the battery in the morning on a sunny day.  But the current with which the battery can be charged is limited so they'll export most of the excess.  Then they can run the immersion heater to re-heat the hot water tank for an hour or two but they'll probably have more power than the 3 kW needed to do this, most of which will get exported.  Then it's maybe 2 pm and they will export most of the electricity generated for the rest of the afternoon.  It's different in winter but they will generate very much less solar power then.     

Ok lota for me to absorb here thank you. My dad was actually thinking about whether 2 batteries were worthwhile, sounds like that would be overkill. I also read somewhere it does take 20yrs or so to break even but by then you are looking at high maintanence costs... really hard to decide if its right economically in the long term, even though it certainly is environmentally.

FreeBear

sazzlelondon said:  really hard to decide if its right economically in the long term, even though it certainly is environmentally.

You need to read up on the environmental damage caused by mining of the materials used in solar panels & batteries - Much of it is really dirty business and does a huge amount of damage.

MWT

sazzlelondon said:

Reed_Richards said:

You (or rather your parents) will export lots, or generate a lot of power that could be exported if export were not limited (without special permission).  During the summer months they'll likely be able to charge the battery in the morning on a sunny day.  But the current with which the battery can be charged is limited so they'll export most of the excess.  Then they can run the immersion heater to re-heat the hot water tank for an hour or two but they'll probably have more power than the 3 kW needed to do this, most of which will get exported.  Then it's maybe 2 pm and they will export most of the electricity generated for the rest of the afternoon.  It's different in winter but they will generate very much less solar power then.     

Ok lota for me to absorb here thank you. My dad was actually thinking about whether 2 batteries were worthwhile, sounds like that would be overkill. I also read somewhere it does take 20yrs or so to break even but by then you are looking at high maintanence costs... really hard to decide if its right economically in the long term, even though it certainly is environmentally.

Why don’t you post the basic details of the equipment they propose to install, the cost and the name of the company, so you can get some more informed feedback?
The are some great installers out there and also some you would never want to use…

tacpot12

There has been a very big take up of solar, but now that the Feed In Tarrifs have been reduced, it is not the money-generaing scheme it once was, hence installations have slowed down a bit. But they are still a sensible choice and will pay for themselves in the electricity (or gas) that you won't have to buy, providing you can set them up to use most of what they produce. Running an immersion heater from them to heat a tank of hot water is a good arrangement. 

If you don't already have a hot water cylinder, adding one is going to add to the cost of installing solar, but it will me nuch  cheaper than adding an battery, and will provide some of the same benefit. 

[Deleted User]

A few facts to work on. I have a 7kWp array with a 13.5kW Powerwall2 battery; a solar diverter for hot water heating and an electric vehicle. The system generates about 5700kWhs/year of which 160kWhs is generated in December. December daily outputs vary from 10kWhs to 300Whs . I export about 2000kWhs/year to the Grid and import about 800kWhs/year from the Grid during the Winter period. My wife and I are retired and at home all day.

To sum up, the array and battery meet our daily needs from late March through until late September. We then have no option but to import energy. As others have said, it is impossible to use all the energy an array generates in Summer and the array will not generate enough energy to be self-sufficient in the Winter.

Will it pay for itself? All I can say is that the ‘man maths’ have got considerably better in the past few weeks! PS. Make sure that your installer understands the VAT rules for over 60s.

PPS: all batteries are treated as potential electricity generators. There is no restriction on the amount of solar that can be put on a roof; however, the DNO has to approve the proposed installation (at cost) and it may impose a total export to grid power limit based on the state of the local electrical infrastructure. The export limit can vary from the max solar output plus any battery export to not a lot. 

Reed_Richards

tacpot12 said:

There has been a very big take up of solar, but now that the Feed In Tarrifs have been reduced, it is not the money-generaing scheme it once was, hence installations have slowed down a bit. But they are still a sensible choice and will pay for themselves in the electricity (or gas) that you won't have to buy, providing you can set them up to use most of what they produce.... 

The "providing" bit is the very hard part, much much easier said than done.  I think it is more realistic to accept that you will not be able to use a lot of the electricity you generate but over capacity may still be worthwhile to help in winter and on cloudy days when the panels will only generate a fraction of their maximum output.

I recommend you post your question here: https://forums.moneysavingexpert.com/categories/green-ethical-moneysaving for more answers from solar panel owners.  

matelodave

sazzlelondon said:

Reed_Richards said:

You (or rather your parents) will export lots, or generate a lot of power that could be exported if export were not limited (without special permission).  During the summer months they'll likely be able to charge the battery in the morning on a sunny day.  But the current with which the battery can be charged is limited so they'll export most of the excess.  Then they can run the immersion heater to re-heat the hot water tank for an hour or two but they'll probably have more power than the 3 kW needed to do this, most of which will get exported.  Then it's maybe 2 pm and they will export most of the electricity generated for the rest of the afternoon.  It's different in winter but they will generate very much less solar power then.     

Ok lota for me to absorb here thank you. My dad was actually thinking about whether 2 batteries were worthwhile, sounds like that would be overkill. I also read somewhere it does take 20yrs or so to break even but by then you are looking at high maintanence costs... really hard to decide if its right economically in the long term, even though it certainly is environmentally.

You need to decide whether you are going for them because you want to be green or you want to save money.

You really do need to do the sums if you are hoping to save money, especially if your paraents are "elderly" (whatever that means). The payback period of the panels could easily exceed 10 years and even more, if at all for the battery, so you have to be convinced that they will remain living in the place for the next ten years or so to make it financially viable..

Just my opinion.