Photovoltaic systems
Discussion
Hi all.
Does anyone have a pv system installed at their home/office. I’m thinking of investing in one and the prices are really dropping now - <£10k for 15kw
Is there anyone to avoid? Comments/ lessons learned along the way that is fellow PHers may benefit from.
Just a general conversation starter really!!!!
Does anyone have a pv system installed at their home/office. I’m thinking of investing in one and the prices are really dropping now - <£10k for 15kw
Is there anyone to avoid? Comments/ lessons learned along the way that is fellow PHers may benefit from.
Just a general conversation starter really!!!!
Do the sums very carefully - how will you use the power?
In the winter you will get sod all, in the summer you'll get loads. There's no FIT any more, there may be something else in the future but it isn't there now.
In a domestic setting, most of your power use does not coincide with peak generation, so of your (say) £1000 a year power bill, the panels might knock out £300 a year. That will take a long time to get your 10K back. To make it more effective, you need batteries, which is further expense. Certainly in a domestic setting,, the best approach is to use a DHW power diverter - costs £200 and dumps all the surplus in the hot water tank.
In the winter you will get sod all, in the summer you'll get loads. There's no FIT any more, there may be something else in the future but it isn't there now.
In a domestic setting, most of your power use does not coincide with peak generation, so of your (say) £1000 a year power bill, the panels might knock out £300 a year. That will take a long time to get your 10K back. To make it more effective, you need batteries, which is further expense. Certainly in a domestic setting,, the best approach is to use a DHW power diverter - costs £200 and dumps all the surplus in the hot water tank.
There's no government FIT but you can get commercial tariffs where you sell excess power to an energy provider rather than just losing it (albeit not for very much): https://octopus.energy/outgoing/
ETA: You'd probably get more responses in "Homes, Gardens and DIY".
ETA: You'd probably get more responses in "Homes, Gardens and DIY".
Edited by kambites on Thursday 6th June 09:29
Since the FIT ended the best thing is to get a smaller PV system and add a battery. Then you can store the energy for when you need it and your bill will come down a lot more.
If you have an EV you can drive for free, but doing 12k miles/year with pre-heating I was only spending abut £25/month to charge it anyway.
If you have an EV you can drive for free, but doing 12k miles/year with pre-heating I was only spending abut £25/month to charge it anyway.
Thanks for the responses.
We apparently use 5x the national average. An electric car, a hot tub, a koi pond and a wife unable to cope without 30 bulbs on see to that. At my lowest usage I am doing 2 kw/h. At peak worst case about 15.
I need to speak to a provider and understand it better.
We apparently use 5x the national average. An electric car, a hot tub, a koi pond and a wife unable to cope without 30 bulbs on see to that. At my lowest usage I am doing 2 kw/h. At peak worst case about 15.
I need to speak to a provider and understand it better.
kuro68k said:
Since the FIT ended the best thing is to get a smaller PV system and add a battery. Then you can store the energy for when you need it and your bill will come down a lot more.
If you have an EV you can drive for free, but doing 12k miles/year with pre-heating I was only spending abut £25/month to charge it anyway.
You might “save” buying more electricity by having a battery but you would have shelled out around £9k for one Tesla power wall fitted which holds all of about £2 of electricity and will probably take 12 years or more to pay back (assuming you save one lot of a capacity a day for the whole year which is only going to happen with solar and wind. So it isn’t going to happen!)If you have an EV you can drive for free, but doing 12k miles/year with pre-heating I was only spending abut £25/month to charge it anyway.
I just had a quick look online at some figures for solar and ignoring borrowing costs payback is over 20 years as there’s no fees in tariff any more.
For solar and batteries to provide something worthwhile financially I think you need different tariffs during each day and to be able to shift use to cheap times and / or the leccy generators to buy your production / or be able to stick cheap leccy into your car battery and sell to the grid at peak times.
I did hear on a fully charged podcast today talk of the grid paying you to take power at certain times (prob v windy middle of night in winter!) so there’s scope in the longer term for buying and selling power to get savings but it ain’t here yet
Greg_D said:
We apparently use 5x the national average. An electric car, a hot tub, a koi pond and a wife unable to cope without 30 bulbs on see to that. At my lowest usage I am doing 2 kw/h. At peak worst case about 15.
I need to speak to a provider and understand it better.
Minimum of 2kw seems very high? We use a lot of electricity (3ph, GSHP, electric car etc) but we can get down to 0.5kw fairly easily on a quiet day. You can buy on amazon a £20 no-touch current meter and then it's pretty easy to go through the consumer unit and find out where the power is going.I need to speak to a provider and understand it better.
I've put in 4kw of solar panels, which takes something off the bill (no FiT). I don't know how much we export (for free, to the grid!) but I'll measure it soon and pop in a DHW diverter if it's a large amount. Surprisingly hard to measure solar with three phase. My view is that electricity prices are only going to increase, so it's a long-term investment.
I believe you can put in 4kw on single phase or ~10kw on 3ph pretty easily: above this it becomes commercial solar and more specialised help is required.
I have a 4kWp system which has been running since October 2010, and keep a monthly log of generation, import and export.
Pretty near optimal orientation and no roof shading. On average, it has generated 4mW per year.
The problem is, that it only generates during the light times, and for most of the time it produces a trickle of power, it rarely puts out more than 1.5kWh.
The effect is that I have exported more than half the generated power, and not made a lot in actual energy savings. Thanks to the high FIT at installation time, it has been an excellent investment, but not actually energy efficient here.
I already had solar thermal hot water when I added PV, but f I didn't have; I would use a smart controller to divert excess energy to water heating.
Even if you buy a storage battery system, I'm not sure how the savings would work, as the difference in consumption and generation during the sunniest days will still mean that power is fed back to the grid.
Pretty near optimal orientation and no roof shading. On average, it has generated 4mW per year.
The problem is, that it only generates during the light times, and for most of the time it produces a trickle of power, it rarely puts out more than 1.5kWh.
The effect is that I have exported more than half the generated power, and not made a lot in actual energy savings. Thanks to the high FIT at installation time, it has been an excellent investment, but not actually energy efficient here.
I already had solar thermal hot water when I added PV, but f I didn't have; I would use a smart controller to divert excess energy to water heating.
Even if you buy a storage battery system, I'm not sure how the savings would work, as the difference in consumption and generation during the sunniest days will still mean that power is fed back to the grid.
I'm in this industry - have been for over 10 years.
Yes the feed-in tariff has gone now, so producing your own energy is best for high daytime energy consumers (someone home in the day times). If you have an EV, can make a lot of sense.
The systems are very reliable. A good installer can be found relatively easily - since the feed in tariff has ended most of the cowboys moved on.
If you are looking for payback, stick it in an S&S ISA. If you want to secure your own energy instead of buying mainly Nuclear energy, then Solar is a very good choice.
Suppliers will also pay for export around 5p kWh.
PM me if you would like any advice. (I am not an installer)
Yes the feed-in tariff has gone now, so producing your own energy is best for high daytime energy consumers (someone home in the day times). If you have an EV, can make a lot of sense.
The systems are very reliable. A good installer can be found relatively easily - since the feed in tariff has ended most of the cowboys moved on.
If you are looking for payback, stick it in an S&S ISA. If you want to secure your own energy instead of buying mainly Nuclear energy, then Solar is a very good choice.
Suppliers will also pay for export around 5p kWh.
PM me if you would like any advice. (I am not an installer)
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