Discussion
PF62 said:
OutInTheShed said:
PF62 said:
dmsims said:
I think a more realistic price would be £2.5K
Including installation?The problem is, retrofitting stuff to houses is a faff.
I'm sure there are a few people driving Ferarris off the back of installing solar panels etc, but nobody is stopping anyone from training to do it and setting up in business.
What annoys me a lot is seeing new houses built with no solar. Including it at the design phase ought to be a given.
PF62 said:
soupdragon1 said:
Probably need to work out the life span of the battery too.
Eg, say it lasts 15 years and you spent £5000. That's basically £1 per day or 3kw equivalent at peak rate. So ideally, you need a benefit of £1 a day from your £5k investment from a pure monetary point of view.
Example:
I buy a 10kwh battery for £5k. Each day, I fill it for 75p at night rate. It stops me using 10kw at day rate, so I don't spend 350p. I save £2.75 a day. I lose £1 depreciation so my net saving is £1.75 per day.
Your assumption is that the day rate is 35p/kWh, and quite simply it isn't, because if you didn't have the battery you would be on a more sensible tariff paying around 18p/kWh and so instead of saving £2.75 a day you are saving around £1.05 a day.Eg, say it lasts 15 years and you spent £5000. That's basically £1 per day or 3kw equivalent at peak rate. So ideally, you need a benefit of £1 a day from your £5k investment from a pure monetary point of view.
Example:
I buy a 10kwh battery for £5k. Each day, I fill it for 75p at night rate. It stops me using 10kw at day rate, so I don't spend 350p. I save £2.75 a day. I lose £1 depreciation so my net saving is £1.75 per day.
Deduct your £1 depreciation and you are now saving 5p a day!
soupdragon1 said:
If you've got solar though, you might not save that because you're going to be using the solar for a large chunk of daily usage, so if you only deplete your battery once every 3 days, you lose 25p. But, you're not working the battery as hard, so it might last longer lol 
.
Yes, your financial losses will be even greater if you have solar and a battery..soupdragon1 said:
Yeah, its hard to model.
Nah, it's dead easy for the shiny suited solar & battery salesmen knocking on people's doors showing them how much they will save...I was responding to the point about a battery being a viable investment, and indicating a method one might consider to see if it's viable or not. Battery good vs battery bad isn't an answerable question without a ton of data to work off. I thought that was obvious. 35p, £5k etc - I literally pulled those figures from thin air. Everyone needs to do their own figures.
soupdragon1 said:
I've had my post quoted a couple of times but just to be clear, I'm not making any assumptions at all. It's literally impossible to model something that will be relevant to all of us as it's a very bespoke cost analysis which is individual.
I was responding to the point about a battery being a viable investment, and indicating a method one might consider to see if it's viable or not. Battery good vs battery bad isn't an answerable question without a ton of data to work off. I thought that was obvious. 35p, £5k etc - I literally pulled those figures from thin air. Everyone needs to do their own figures.
You may have pulled those figures out of thin air, but the issue is there is more than a little reticence from anyone giving any details that doesn't show that solar / battery is just and expensive hobby.I was responding to the point about a battery being a viable investment, and indicating a method one might consider to see if it's viable or not. Battery good vs battery bad isn't an answerable question without a ton of data to work off. I thought that was obvious. 35p, £5k etc - I literally pulled those figures from thin air. Everyone needs to do their own figures.
PF62 said:
soupdragon1 said:
I've had my post quoted a couple of times but just to be clear, I'm not making any assumptions at all. It's literally impossible to model something that will be relevant to all of us as it's a very bespoke cost analysis which is individual.
I was responding to the point about a battery being a viable investment, and indicating a method one might consider to see if it's viable or not. Battery good vs battery bad isn't an answerable question without a ton of data to work off. I thought that was obvious. 35p, £5k etc - I literally pulled those figures from thin air. Everyone needs to do their own figures.
You may have pulled those figures out of thin air, but the issue is there is more than a little reticence from anyone giving any details that doesn't show that solar / battery is just and expensive hobby.I was responding to the point about a battery being a viable investment, and indicating a method one might consider to see if it's viable or not. Battery good vs battery bad isn't an answerable question without a ton of data to work off. I thought that was obvious. 35p, £5k etc - I literally pulled those figures from thin air. Everyone needs to do their own figures.
It was quite obvious to me that solar was a viable investment but I find it a bit trickier to work out if battery is too. That's partly why I have left it battery ready. I will collect actual data for 12 months and then decide.
I'm lucky that I've an official weather station a couple of miles away, so using the solar calculators, which are based off that actual weather station, I could easily see that the panels would cover their own costs in 5 to 6 years. The complexity of having 2 EVs makes the adding a battery question more complex to work out.
PF62 said:
You may have pulled those figures out of thin air, but the issue is there is more than a little reticence from anyone giving any details that doesn't show that solar / battery is just and expensive hobby.
I'll admit that I can't provide full data for a year, so I'll set my stall out at this and hopefully if the thread is still going in a year I'll report back, but my setup outlay was just under 11 grand, including 15kwh of battery, 8.2kwp of solar panels. Our usage, including EV, is 11000kwh of electricity per year, the split of which is 5200 to the house, remainder to EV. Under the price cap scheme, the price was roughly 30p per kwh, so an annual cost of £3300 - this broadly matched the bills. We've now shifted to Octopus Agile, and the solar/battery/EV setup is all integrated, such that the following happens:
1) If the solar output for the following day is predicted to be crap, then the batteries will fill overnight at the cheapest prices.
2) If there's adequate solar output, then the excess produced during the day is sent to the battery first, and, when that's at 100%, dumped to the car. Finally if all of that is done (batteries at full, car unavailable or full) then the remainder is exported.
3) The plan is to use everything that we can, and export close to nothing although in practice this is likely to be unrealistic.
If utilising just Octopus Agile, the overall cost over the last year is 15.78p, so that would see my usage at approximately £1735.80.
I think that overall, after a year, my average unit price will be in the region of 2.25-2.75p per kwh, based on the sum of solar used + import. Anything exported isn't included in this calculation but would perhaps shift it lower. On that basis, it should be the case that the cost for all electricity is around £275. That should mean that:
1) Against the price cap, there's a saving of £3025 per year, so repayment in just under four years.
2) Against the historical average over the last year, a saving of £1461, so repayment would be in around 7.5 years.
I'm aware there's a lot of ifs/buts in this, for instance that there's an assumption that the EV charging would be at the average price, that the usage remains static and so on so this isn't perfect by any stretch of the imagination.
The system has been in for a couple of months so far, since around the time of the winter equinox, and at the moment we're running an average cost per kwh of 0.087p per kwh which I expect will reduce dramatically as we get into the winter months and hopefully only rise a little into the latter part of the year as we approach a year of usage. I think that the massive unknown of export pricing will sway things quite dramatically too.
I was of a similar opinion as you that it's marginal at best, and the reason for my installation is primarily to support reduced costs for EV charging. I think in reality that payback will be between the two figures shown above - there is a degree of man maths in that we were previously price cap users so it's easy to fall into the mindset of it being closer to the £3025 figure given that's where we've come from but those more against it will point to the 7.5 years figure. I think that in reality the middle ground will be somewhere between the two.
The problem is the electricity industry is changing quite quickly.
Lots of commercial solar is being built, that will change the market.
Clever tariffs work for some people at the moment, but the market will change as more renewables come on stream and more people share the gains of agile type tariffs.
Commercial scale battery installations may soon smooth out intra-day price variations. Along with faster responding gas fired stations.
Batteries and panels keep getting cheaper.
We could have another gas price spike or we could find energy gets cheaper.
My guess is that we might soon get back to the situation where it only makes sense whan you can use all the power you generate, to avoid importing power. Like if you have an office needing aircon or a business needing fridges. The big players have so much lower costs than amateurs.
Some people who timed it well may get the bulk of their money back before that kicks in?
I think the government (and industry) has been keen to promote domestic solar, it is good politically and takes money from the wealthy and distributes it to White Van Man, who spends freely. This was even more true with subsidised FIT which was really QE off the books.
Personally, I'm considering a house move, one candidtate place could have about 5kW of E and 5kW of W facing panels and a bit of South, all easy to DIY install on outbuildings. That could be very cheap.
It's a ll a distraction though, the big question is how will we heat our homes in 20 to 30 years' time?
In February, I used 2000kWh of gas. That would take at least 600kWh of electricity into a heat pump to replace it?
A 3.6kW solar array I follow mananged 160kWh this february.
Solar doesn't solve the problems.
I might be planting some 'energy crops'.
Lots of commercial solar is being built, that will change the market.
Clever tariffs work for some people at the moment, but the market will change as more renewables come on stream and more people share the gains of agile type tariffs.
Commercial scale battery installations may soon smooth out intra-day price variations. Along with faster responding gas fired stations.
Batteries and panels keep getting cheaper.
We could have another gas price spike or we could find energy gets cheaper.
My guess is that we might soon get back to the situation where it only makes sense whan you can use all the power you generate, to avoid importing power. Like if you have an office needing aircon or a business needing fridges. The big players have so much lower costs than amateurs.
Some people who timed it well may get the bulk of their money back before that kicks in?
I think the government (and industry) has been keen to promote domestic solar, it is good politically and takes money from the wealthy and distributes it to White Van Man, who spends freely. This was even more true with subsidised FIT which was really QE off the books.
Personally, I'm considering a house move, one candidtate place could have about 5kW of E and 5kW of W facing panels and a bit of South, all easy to DIY install on outbuildings. That could be very cheap.
It's a ll a distraction though, the big question is how will we heat our homes in 20 to 30 years' time?
In February, I used 2000kWh of gas. That would take at least 600kWh of electricity into a heat pump to replace it?
A 3.6kW solar array I follow mananged 160kWh this february.
Solar doesn't solve the problems.
I might be planting some 'energy crops'.
OutInTheShed said:
PF62 said:
OutInTheShed said:
PF62 said:
dmsims said:
I think a more realistic price would be £2.5K
Including installation?The problem is, retrofitting stuff to houses is a faff.
I'm sure there are a few people driving Ferarris off the back of installing solar panels etc, but nobody is stopping anyone from training to do it and setting up in business.
What annoys me a lot is seeing new houses built with no solar. Including it at the design phase ought to be a given.
snobetter said:
Friend of mine who's a roofer has trained to do solar installs, but doesn't promote it, says it's just handy to have when x% of a new build needs them he can do the whole service. He was saying it's a standard planning requirement that so many should have them.
My niece's boyfriend is in his early 20's, straight out of school into roofing type work and quickly got into solar. Left the firm he worked for to setup his own Ltd with his mate and now travels all over the country doing large-scale commercial PV fitting hundreds of panels at a time. No degree, no student debt, just a grafter who saw an opportunity and is doing brilliantly. I've got a lot of respect for the lad.mrmistoffelees said:
I'll admit that I can't provide full data for a year, so I'll set my stall out at this and hopefully if the thread is still going in a year I'll report back, but my setup outlay was just under 11 grand, including 15kwh of battery, 8.2kwp of solar panels. Our usage, including EV, is 11000kwh of electricity per year, the split of which is 5200 to the house, remainder to EV.
Under the price cap scheme, the price was roughly 30p per kwh, so an annual cost of £3300 - this broadly matched the bills. We've now shifted to Octopus Agile, and the solar/battery/EV setup is all integrated, such that the following happens:
1) If the solar output for the following day is predicted to be crap, then the batteries will fill overnight at the cheapest prices.
2) If there's adequate solar output, then the excess produced during the day is sent to the battery first, and, when that's at 100%, dumped to the car. Finally if all of that is done (batteries at full, car unavailable or full) then the remainder is exported.
3) The plan is to use everything that we can, and export close to nothing although in practice this is likely to be unrealistic.
If utilising just Octopus Agile, the overall cost over the last year is 15.78p, so that would see my usage at approximately £1735.80.
I think that overall, after a year, my average unit price will be in the region of 2.25-2.75p per kwh, based on the sum of solar used + import. Anything exported isn't included in this calculation but would perhaps shift it lower. On that basis, it should be the case that the cost for all electricity is around £275. That should mean that:
1) Against the price cap, there's a saving of £3025 per year, so repayment in just under four years.
2) Against the historical average over the last year, a saving of £1461, so repayment would be in around 7.5 years.
I'm aware there's a lot of ifs/buts in this, for instance that there's an assumption that the EV charging would be at the average price, that the usage remains static and so on so this isn't perfect by any stretch of the imagination.
The system has been in for a couple of months so far, since around the time of the winter equinox, and at the moment we're running an average cost per kwh of 0.087p per kwh which I expect will reduce dramatically as we get into the winter months and hopefully only rise a little into the latter part of the year as we approach a year of usage. I think that the massive unknown of export pricing will sway things quite dramatically too.
I was of a similar opinion as you that it's marginal at best, and the reason for my installation is primarily to support reduced costs for EV charging. I think in reality that payback will be between the two figures shown above - there is a degree of man maths in that we were previously price cap users so it's easy to fall into the mindset of it being closer to the £3025 figure given that's where we've come from but those more against it will point to the 7.5 years figure. I think that in reality the middle ground will be somewhere between the two.
You need to factor in the interest lost on your £11K. You could get 4% net of tax on a 25 year gilt.Under the price cap scheme, the price was roughly 30p per kwh, so an annual cost of £3300 - this broadly matched the bills. We've now shifted to Octopus Agile, and the solar/battery/EV setup is all integrated, such that the following happens:
1) If the solar output for the following day is predicted to be crap, then the batteries will fill overnight at the cheapest prices.
2) If there's adequate solar output, then the excess produced during the day is sent to the battery first, and, when that's at 100%, dumped to the car. Finally if all of that is done (batteries at full, car unavailable or full) then the remainder is exported.
3) The plan is to use everything that we can, and export close to nothing although in practice this is likely to be unrealistic.
If utilising just Octopus Agile, the overall cost over the last year is 15.78p, so that would see my usage at approximately £1735.80.
I think that overall, after a year, my average unit price will be in the region of 2.25-2.75p per kwh, based on the sum of solar used + import. Anything exported isn't included in this calculation but would perhaps shift it lower. On that basis, it should be the case that the cost for all electricity is around £275. That should mean that:
1) Against the price cap, there's a saving of £3025 per year, so repayment in just under four years.
2) Against the historical average over the last year, a saving of £1461, so repayment would be in around 7.5 years.
I'm aware there's a lot of ifs/buts in this, for instance that there's an assumption that the EV charging would be at the average price, that the usage remains static and so on so this isn't perfect by any stretch of the imagination.
The system has been in for a couple of months so far, since around the time of the winter equinox, and at the moment we're running an average cost per kwh of 0.087p per kwh which I expect will reduce dramatically as we get into the winter months and hopefully only rise a little into the latter part of the year as we approach a year of usage. I think that the massive unknown of export pricing will sway things quite dramatically too.
I was of a similar opinion as you that it's marginal at best, and the reason for my installation is primarily to support reduced costs for EV charging. I think in reality that payback will be between the two figures shown above - there is a degree of man maths in that we were previously price cap users so it's easy to fall into the mindset of it being closer to the £3025 figure given that's where we've come from but those more against it will point to the 7.5 years figure. I think that in reality the middle ground will be somewhere between the two.
MaxFromage said:
You need to factor in the interest lost on your £11K. You could get 4% net of tax on a 25 year gilt.
That's true, but then how would you quantify the ongoing savings after y4/y7.5? Yes you're losing interest, but that interest doesn't suddenly go stratospheric at a certain point. Beyond y4 there's a benefit of £2.7k so on the basis of a 25 year gilt at 4%, after 25y you're at £18851 interest (profit). After 21y of £2700 savings, you're at £46700 profit, again making a lot of assumptions of no equipment failure, static energy prices, and so on but given that's all I have to work with. Even so, that's still a decent margin to soak up failure against the interest.cayman-black said:
mrmistoffelees, I think for what you paid thats a good deal and a decent pay back also.
can I ask who you used are they one of the big companies or a local supplier as I,m looking now. tia.
Hi, it's a local supplier covering north-west Wales (Anglesey to Denbighshire but they don't go very far south into Gwynedd). If you're in that kind of area send me a message. I won't put their name here because they do stuff for me through work and they're booked up until the summer with some of my projects there. can I ask who you used are they one of the big companies or a local supplier as I,m looking now. tia.
mrmistoffelees said:
That's true, but then how would you quantify the ongoing savings after y4/y7.5? Yes you're losing interest, but that interest doesn't suddenly go stratospheric at a certain point. Beyond y4 there's a benefit of £2.7k so on the basis of a 25 year gilt at 4%, after 25y you're at £18851 interest (profit). After 21y of £2700 savings, you're at £46700 profit, again making a lot of assumptions of no equipment failure, static energy prices, and so on but given that's all I have to work with. Even so, that's still a decent margin to soak up failure against the interest.
Yes there's a lot of assumptions you have to make, but all you can do is model as best as you can.theboss said:
My niece's boyfriend is in his early 20's, straight out of school into roofing type work and quickly got into solar. Left the firm he worked for to setup his own Ltd with his mate and now travels all over the country doing large-scale commercial PV fitting hundreds of panels at a time. No degree, no student debt, just a grafter who saw an opportunity and is doing brilliantly. I've got a lot of respect for the lad.
Surely he needs an electrical qualification to connect them to sign them off an connect them to the grid?MaxFromage said:
PF62 said:
Which then pushes the repayment period out to 12 years.
Yes and that system is decent value compare to some. Many of the quotes we see here simply aren't going to ever pay back unfortunately.mrmistoffelees said:
MaxFromage said:
You need to factor in the interest lost on your £11K. You could get 4% net of tax on a 25 year gilt.
That's true, but then how would you quantify the ongoing savings after y4/y7.5? Yes you're losing interest, but that interest doesn't suddenly go stratospheric at a certain point. Beyond y4 there's a benefit of £2.7k so on the basis of a 25 year gilt at 4%, after 25y you're at £18851 interest (profit). After 21y of £2700 savings, you're at £46700 profit, again making a lot of assumptions of no equipment failure, static energy prices, and so on but given that's all I have to work with. Even so, that's still a decent margin to soak up failure against the interest.And man-mathing much the same payback periods.
You need to spend the money on something - eventually - or what is the point having it.
Why would you be saving £5k at 5%? To generate £250 per year. Will solar give you more than £250 per year of free leccy? Almost certainly.
Why would you be saving £8k at 5%. To generate £400 per year. Will a battery store more than £400 per year than you could export. Probably not.
The ultimate question is what do you want to spend that initial capital on? Whatever it is, it will be unlikely to return any sort of profit, but if you can get a £13k Porsche, who cares about profit?
Why would you be saving £5k at 5%? To generate £250 per year. Will solar give you more than £250 per year of free leccy? Almost certainly.
Why would you be saving £8k at 5%. To generate £400 per year. Will a battery store more than £400 per year than you could export. Probably not.
The ultimate question is what do you want to spend that initial capital on? Whatever it is, it will be unlikely to return any sort of profit, but if you can get a £13k Porsche, who cares about profit?
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