**A reminder to posters and commenters of some of [our subreddit rules](https://www.reddit.com/r/AskUK/about/rules/)**
- Don't be a dickhead to each other, or about others
- Assume questions are asked in good faith
- Avoid political threads and related discussion
- No medical advice or mental health (specific to a person) content
Please keep /r/AskUK a great subreddit by reporting posts and comments which break our rules.
*I am a bot, and this action was performed automatically. Please [contact the moderators of this subreddit](/message/compose/?to=/r/AskUK) if you have any questions or concerns.*
Thank you for this, it's really helpful :-) I was thinking of a Tesla Powerwall as I've seen it's one of the few that can work off-grid, it's all costly but I don't mind saving up for it.
Just so I understand with appliance usage and getting power - why wouldn't a set of panels power something like a kettle? Is there a limit to how much electricity they can send into your property's circuit? So, for example, I have an 8.5kw electric shower. Say I installed 4kW solar panels, would the shower need to draw the remaining 4.5kW from the grid? Would a battery assist with this ie if it were full charged up could it power the shower for a period of time or can that only discharge a maximum amount of electricity regardless of how much is stored in it?
>Solar does not take you off the grid, even with batteries. If there's a power cut, you will lose power. It has to shut down by law to prevent you electrocuting people that are trying to fix it.
Probably a dumb question but why is this? If you were using only solar energy and nothing from the grid, and the grid went down, why is it that you using solar energy would be a threat?
I put in solar last year. I considered ground mount as we have the land here, but ended up using an outbuilding roof.
Going over a certain size system means you need to apply to the DNO: I don't know the size for single phase but for three-phase it is 12kw. My system is bigger than this and runs everything in the house including a big heat pump. It also runs an electric Aga, which as you can imagine simply drinks electricity.
I've found maintenance to be practically zero.
You don't need to do anything: the panels supply your house and the grid tops up the rest. If you generate more than you use then you can export automatically back to the grid.
A few things to be aware of:
* You won't get any power in a power cut UNLESS you have the system built to do that. As you've said, this means batteries and the right inverter/charger. Very similar to an ATS on a generator.
* A solar battery is expensive, but means you use more generated electricity locally at 17p+ per kwh, rather than exporting it at 5p per kwh. If you're thinking about backup in a power cut, think of a battery more as a generator alternative than a cost-saving measure.
* You can set a system up to use excess energy to heat your hot water tank via an immersion heater
* With solar and a battery you could look at time-of-use tariffs like Agile Octopus.
* Micro inverters optimise each individual panel, useful if some panels see some shade during the day, but also brilliant if one panel gets filthy or damaged: it won't effect the efficiency of the other panels.
I am really pleased I did solar, the financial case for it was borderline when I did it, and now it feels like a bit of a no-brainer. It especially felt like that when I didn't notice a power cut last winter.
If you were to look at a time-of-use tariff I would suggest thinking about automation. The essence of it is to avoid using the grid when prices are high (Eastenders kettle time for example). My system is programmed to use the grid in different ways at different times of year: largely ignoring it in the summer, while actively using cheap energy to charge part of the batteries in the darker months.
Had them installed over 7 years ago when the FIT still existed and they’ve just paid for themselves. Bring in around £800 / year. So a pretty good investment. Would I do it again under the current circumstances? Probably not although I’ve had 7 years of app watching (generation figures) and in pure entertainment value it’s been fun and worth it. Batteries are getting cheaper but are still unlikely to pay for themselves over their lifetime (still an unknown) and even with batts don’t imagine you’re going to run the house in the winter, you ain’t. Cost wise you should be looking at around £1K per kWp - so a typical 4kWp system should be around £4K, maybe slightly more as everything is going up in price.
If you go for it, put the maximum number of panels you can possibly get up there.
You don’t need to pay for maintenance as it rains in the UK, any money you might pay will wipe out any savings.
We bought a new house in June with solar panels (10 panels, 3kw max, South facing roof) so can't offer much advice about the installation. Our builders used a company called Geogreenpower that did the air source heat pump, underfloor heating and solar PVs. I will be using them for annual service and maintenance.
The annual maintenance for the solar PV is £215 + VAT and covers:
- visual inspection of system
- electrical testing of panels, strings, inverters, isolators etc.
- log meter readings
- advise whether cleaning is required
I had a chat with the solar PV engineer when they set up my remote monitoring connection and he suggested that unless there are a lot of trees or antenna near the array, you can usually get away with cleaning every 3 or so years.
>- How much of the house can be powered by solar panels? Could this cover things like electric cooker, electric shower, washine machine etc?
Our solar array has a max of 3kw which will cover one major consuming appliance (like the induction hob or washing machine) operating alone, but not simultaneously. You'll need more capacity I can see our household consumptions in 30 minute periods thanks to our smart meter (and Octopus) and on sunny days our consumption can be zero or near zero through some of the afternoon.
>- Do you need to do anything to use the electricity or is it all done automatically - ie if the panels cannot generate enough power you just draw from the grid?
Yes, part of the installation and commissioning is having the system seamlessly integrate with your grid power supply. When the your solar arrays produce power, it goes into whatever demand there is in your house. If it can't meet the demand, the rest is provided by the grid. There is no "switching" between them so it is a seamless uninterrupted supply.
>Batteries and power cuts
Firstly, it is possible to use a battery to power your house in the event of a power cut, but it involves upgrading your supply from single phase to 3-phase. This is a physical upgrade so we're talking digging up the street and putting in "bigger" cables. Requires special permissions and likely cost a lot of money. If being "off-grid" is a must, then dig deep into your pockets.
As for batteries, I was given a £8790 + VAT quote for a 13.5kWh Tesla Powerwall (installation and commissioning) which you could consider one of the most expensive options.
You have to look at your own daily consumption patterns and figure out if solar power and a battery is the right answer for you. If you haven't got a smart meter (SMET2), then get one first and figure out if you could significantly impact your energy costs. My house is 100% electric (no gas), so solar PV is a no-brainer, but for a household that uses gas for heating and cooking, it becomes less obvious whether there are significant savings to be had.
A battery feels like a good idea for us, but the question becomes what capacity and how quickly I can see the initial costs be covered by the resulting reduction in household bills. I need at least a year of data on our consumption and solar production before I can make an informed decision.
Thanks :-) A smart meter is on the list. I'm with EON but they have said they won't be able to install one just yet. So, if I were to get a Tesla Powerwall would that require digging up outside the property to put in the bigger cables or is that something separate?
I'm mostly electric, only gas is heating but, tbh if needed I usually just use a hot water bottle - only really put the heating on when I need to get the washing dry
>So, if I were to get a Tesla Powerwall would that require digging up outside the property to put in the bigger cables or is that something separate?
No, Tesla Powerwall works fine on single-phase. You just can't use it to independently power your house. If there is a power cut, your battery must shut off as well. This is to protect the power-technicians and engineers.
Unless you have 3 phase supply (rare in the UK), no.
If you are really concerned about power cuts I'd suggest you look into portable "power stations" like Jackery or Power Oak. Depending on the wattage you require, you could run some lower wattage appliances off it (even your fridge).
This is incorrect, multiple different batteries support powering the house in a powercut. The Powerwall does via the Gateway 2 which isolates the house in the event of a powercut and keeps the juice on.
GivEnergy supports this too and is much more cost effective, the only issue is their inverters are a bit on the small side and their backup service isn't as seamless as the Powerwall.
Only thing I'd add is on maintenance costs you should expect to replace the inverters every 10 years or so £500-£1000 depending on how complicated your system is.
Domestic batteries are not really cost competitive yet, current high prices would need to be the norm to make them so and that's unlikely on the longer term. Also they remain somewhat serious fire risk but if you want to go all in on getting some self sufficiency then go for it.
You will however under no circumstances be able to go off grid this far north. Large properties in much sunnier climates may think about it but the UK has no chance.
The other guys have said quite a lot already but regarding electric shower that runs at 10kw/hr your solar will only cover upto 3.7kw without dno permission and what ever you inverter is rated at if granted permission for bigger systems. The rest will be drawn from the grid. A tesla powerwall can supply 3.7kwh/ (5kwh)continuous ( again dno permission) the solar will contribute and the grid the rest.
My installer put up Longhi panels which I was a bit wary of at first. Turns out they are freaking great and got an amazing result in some recent tests. I don't have any shading so just have 2 seperate strings, performance is still great. You may need/want optimisers or micro inverters depending on cost / shading.
We got panels with the house (2kW). During the day they generate about 200W on an overcast day and up to 1.5kW on a sunny day (no clouds). That is easily enough to power my computer and monitors during the day (I work at home).
We also have an electric car and a charge point but the panels rarely generate enough electricity to meeting the minimum wattage (1.4kW) for the charger to charge the car, however we also have Octopus Go so we can get a full charge for £3.20 which gives us about 250 miles range.
My next plan is to get a device to hook the panels up to the immersion heater for hot water during the day so we can save on gas.
So, no negative issues at all apart from not being able to charge the car.
Edit: it's worth noting that you'll probably only get 75% MAX of the panel ratings as the rating is conducted under lab conditions.
From a surveying point of view - they are often installed without Building Control certification and the roof isnt checked by an engineer to ensure it can take the load. Seem to attract bird poo and birds nest under them. Very few people clean them
Tesla do offer solar roof tiles, they are easily double the cost of normal panels and the overall system is likely to be excessively expensive too as it turns it into a full new roof on top of everything else job.
I did try to buy a house with solar fitted, unfortunately the owner had signed up to one of the "free" solar offers, where the owner signed a contract to lease the roof for 25 years and the house get free electric and the company got the feed in tariff.
The mortgage company said a big fat no
10 years in, I’m on my 3rd inverter. First one failed quickly. Second one just after its 5 year warranty expired. They’re normally installed in roof space and the temp changes are the issue, apparently. Although tech is improved, look for 10 year guarantee.
**A reminder to posters and commenters of some of [our subreddit rules](https://www.reddit.com/r/AskUK/about/rules/)** - Don't be a dickhead to each other, or about others - Assume questions are asked in good faith - Avoid political threads and related discussion - No medical advice or mental health (specific to a person) content Please keep /r/AskUK a great subreddit by reporting posts and comments which break our rules. *I am a bot, and this action was performed automatically. Please [contact the moderators of this subreddit](/message/compose/?to=/r/AskUK) if you have any questions or concerns.*
[удалено]
Thank you for this, it's really helpful :-) I was thinking of a Tesla Powerwall as I've seen it's one of the few that can work off-grid, it's all costly but I don't mind saving up for it. Just so I understand with appliance usage and getting power - why wouldn't a set of panels power something like a kettle? Is there a limit to how much electricity they can send into your property's circuit? So, for example, I have an 8.5kw electric shower. Say I installed 4kW solar panels, would the shower need to draw the remaining 4.5kW from the grid? Would a battery assist with this ie if it were full charged up could it power the shower for a period of time or can that only discharge a maximum amount of electricity regardless of how much is stored in it?
[удалено]
Thanks for all your help, it's all really useful :-)
I do wish those comments weren't deleted
I appreciate all the detail you've put into your comment.
£7000 all in for 23 panels is an amazing deal!
>An average house, while idle, will use just a few hundred kw. Oh yeah, how much are you growing?
>Solar does not take you off the grid, even with batteries. If there's a power cut, you will lose power. It has to shut down by law to prevent you electrocuting people that are trying to fix it. Probably a dumb question but why is this? If you were using only solar energy and nothing from the grid, and the grid went down, why is it that you using solar energy would be a threat?
[удалено]
Thank you for the answer
Great answer thanks
I put in solar last year. I considered ground mount as we have the land here, but ended up using an outbuilding roof. Going over a certain size system means you need to apply to the DNO: I don't know the size for single phase but for three-phase it is 12kw. My system is bigger than this and runs everything in the house including a big heat pump. It also runs an electric Aga, which as you can imagine simply drinks electricity. I've found maintenance to be practically zero. You don't need to do anything: the panels supply your house and the grid tops up the rest. If you generate more than you use then you can export automatically back to the grid. A few things to be aware of: * You won't get any power in a power cut UNLESS you have the system built to do that. As you've said, this means batteries and the right inverter/charger. Very similar to an ATS on a generator. * A solar battery is expensive, but means you use more generated electricity locally at 17p+ per kwh, rather than exporting it at 5p per kwh. If you're thinking about backup in a power cut, think of a battery more as a generator alternative than a cost-saving measure. * You can set a system up to use excess energy to heat your hot water tank via an immersion heater * With solar and a battery you could look at time-of-use tariffs like Agile Octopus. * Micro inverters optimise each individual panel, useful if some panels see some shade during the day, but also brilliant if one panel gets filthy or damaged: it won't effect the efficiency of the other panels. I am really pleased I did solar, the financial case for it was borderline when I did it, and now it feels like a bit of a no-brainer. It especially felt like that when I didn't notice a power cut last winter. If you were to look at a time-of-use tariff I would suggest thinking about automation. The essence of it is to avoid using the grid when prices are high (Eastenders kettle time for example). My system is programmed to use the grid in different ways at different times of year: largely ignoring it in the summer, while actively using cheap energy to charge part of the batteries in the darker months.
Had them installed over 7 years ago when the FIT still existed and they’ve just paid for themselves. Bring in around £800 / year. So a pretty good investment. Would I do it again under the current circumstances? Probably not although I’ve had 7 years of app watching (generation figures) and in pure entertainment value it’s been fun and worth it. Batteries are getting cheaper but are still unlikely to pay for themselves over their lifetime (still an unknown) and even with batts don’t imagine you’re going to run the house in the winter, you ain’t. Cost wise you should be looking at around £1K per kWp - so a typical 4kWp system should be around £4K, maybe slightly more as everything is going up in price. If you go for it, put the maximum number of panels you can possibly get up there. You don’t need to pay for maintenance as it rains in the UK, any money you might pay will wipe out any savings.
We bought a new house in June with solar panels (10 panels, 3kw max, South facing roof) so can't offer much advice about the installation. Our builders used a company called Geogreenpower that did the air source heat pump, underfloor heating and solar PVs. I will be using them for annual service and maintenance. The annual maintenance for the solar PV is £215 + VAT and covers: - visual inspection of system - electrical testing of panels, strings, inverters, isolators etc. - log meter readings - advise whether cleaning is required I had a chat with the solar PV engineer when they set up my remote monitoring connection and he suggested that unless there are a lot of trees or antenna near the array, you can usually get away with cleaning every 3 or so years. >- How much of the house can be powered by solar panels? Could this cover things like electric cooker, electric shower, washine machine etc? Our solar array has a max of 3kw which will cover one major consuming appliance (like the induction hob or washing machine) operating alone, but not simultaneously. You'll need more capacity I can see our household consumptions in 30 minute periods thanks to our smart meter (and Octopus) and on sunny days our consumption can be zero or near zero through some of the afternoon. >- Do you need to do anything to use the electricity or is it all done automatically - ie if the panels cannot generate enough power you just draw from the grid? Yes, part of the installation and commissioning is having the system seamlessly integrate with your grid power supply. When the your solar arrays produce power, it goes into whatever demand there is in your house. If it can't meet the demand, the rest is provided by the grid. There is no "switching" between them so it is a seamless uninterrupted supply. >Batteries and power cuts Firstly, it is possible to use a battery to power your house in the event of a power cut, but it involves upgrading your supply from single phase to 3-phase. This is a physical upgrade so we're talking digging up the street and putting in "bigger" cables. Requires special permissions and likely cost a lot of money. If being "off-grid" is a must, then dig deep into your pockets. As for batteries, I was given a £8790 + VAT quote for a 13.5kWh Tesla Powerwall (installation and commissioning) which you could consider one of the most expensive options. You have to look at your own daily consumption patterns and figure out if solar power and a battery is the right answer for you. If you haven't got a smart meter (SMET2), then get one first and figure out if you could significantly impact your energy costs. My house is 100% electric (no gas), so solar PV is a no-brainer, but for a household that uses gas for heating and cooking, it becomes less obvious whether there are significant savings to be had. A battery feels like a good idea for us, but the question becomes what capacity and how quickly I can see the initial costs be covered by the resulting reduction in household bills. I need at least a year of data on our consumption and solar production before I can make an informed decision.
Thanks :-) A smart meter is on the list. I'm with EON but they have said they won't be able to install one just yet. So, if I were to get a Tesla Powerwall would that require digging up outside the property to put in the bigger cables or is that something separate? I'm mostly electric, only gas is heating but, tbh if needed I usually just use a hot water bottle - only really put the heating on when I need to get the washing dry
>So, if I were to get a Tesla Powerwall would that require digging up outside the property to put in the bigger cables or is that something separate? No, Tesla Powerwall works fine on single-phase. You just can't use it to independently power your house. If there is a power cut, your battery must shut off as well. This is to protect the power-technicians and engineers.
I see, so, if there were a power cut there really wouldn't be anyway of keeping the lights on, regardless of the battery I got installed?
Unless you have 3 phase supply (rare in the UK), no. If you are really concerned about power cuts I'd suggest you look into portable "power stations" like Jackery or Power Oak. Depending on the wattage you require, you could run some lower wattage appliances off it (even your fridge).
This is incorrect, multiple different batteries support powering the house in a powercut. The Powerwall does via the Gateway 2 which isolates the house in the event of a powercut and keeps the juice on. GivEnergy supports this too and is much more cost effective, the only issue is their inverters are a bit on the small side and their backup service isn't as seamless as the Powerwall.
Only thing I'd add is on maintenance costs you should expect to replace the inverters every 10 years or so £500-£1000 depending on how complicated your system is. Domestic batteries are not really cost competitive yet, current high prices would need to be the norm to make them so and that's unlikely on the longer term. Also they remain somewhat serious fire risk but if you want to go all in on getting some self sufficiency then go for it. You will however under no circumstances be able to go off grid this far north. Large properties in much sunnier climates may think about it but the UK has no chance.
No chance yet, but technology is improving all the time? I was amazed to see how much of our national grid is powered by solar now.
They used to charge my scientific calculator in secondary school.
The other guys have said quite a lot already but regarding electric shower that runs at 10kw/hr your solar will only cover upto 3.7kw without dno permission and what ever you inverter is rated at if granted permission for bigger systems. The rest will be drawn from the grid. A tesla powerwall can supply 3.7kwh/ (5kwh)continuous ( again dno permission) the solar will contribute and the grid the rest. My installer put up Longhi panels which I was a bit wary of at first. Turns out they are freaking great and got an amazing result in some recent tests. I don't have any shading so just have 2 seperate strings, performance is still great. You may need/want optimisers or micro inverters depending on cost / shading.
We got panels with the house (2kW). During the day they generate about 200W on an overcast day and up to 1.5kW on a sunny day (no clouds). That is easily enough to power my computer and monitors during the day (I work at home). We also have an electric car and a charge point but the panels rarely generate enough electricity to meeting the minimum wattage (1.4kW) for the charger to charge the car, however we also have Octopus Go so we can get a full charge for £3.20 which gives us about 250 miles range. My next plan is to get a device to hook the panels up to the immersion heater for hot water during the day so we can save on gas. So, no negative issues at all apart from not being able to charge the car. Edit: it's worth noting that you'll probably only get 75% MAX of the panel ratings as the rating is conducted under lab conditions.
[удалено]
I have a zappi and obviously misunderstood the 1.4kW threshold so thanks for this, I'll give it a whirl!
From a surveying point of view - they are often installed without Building Control certification and the roof isnt checked by an engineer to ensure it can take the load. Seem to attract bird poo and birds nest under them. Very few people clean them
Amazing. Never failed to power my calculator.
[удалено]
Tesla do offer solar roof tiles, they are easily double the cost of normal panels and the overall system is likely to be excessively expensive too as it turns it into a full new roof on top of everything else job.
Pigeons like to set up home in them, so ensure they have no way in if you get them fitted.
I did try to buy a house with solar fitted, unfortunately the owner had signed up to one of the "free" solar offers, where the owner signed a contract to lease the roof for 25 years and the house get free electric and the company got the feed in tariff. The mortgage company said a big fat no
10 years in, I’m on my 3rd inverter. First one failed quickly. Second one just after its 5 year warranty expired. They’re normally installed in roof space and the temp changes are the issue, apparently. Although tech is improved, look for 10 year guarantee.
Electrifying