Thinking about solar cells and powerwall.

[sliyk]

Hi everyone,
So as the title suggests. I've been Researching and wi Dow shopping solar PV and powerwalls for a week or two now. I have emailed the tesla certified installers for quotes (new year and Xmas holidays) so will expect more responses in the coming days.
I live in Rugby West midlands with a southish facing roof (picture attached)
I also have a Tesla model 3 performance.
I wanted to ask current solar and powerwall owners what their experience has been like with the whole setup? I'm guessing this is a £15k plus investment so not an easy pill to swallow but with ev charging, immersion water heater and octopus agile might be worth it?

Thanks

 

[Dilly]

As you’ll see from my profile I have what you’ve considering.
The panels came back in 2015 before we’d even considered EV’s.
Then came a PHEV in 2017 along with a Zappi. Then a full EV, another Zappi an Eddi (diverter) and a Powerwall in 2018 followed by more panels a second Powerwall. The model 3 came in 2020.
Big investment, small payback, but satisfaction in spades!
Also on Octopus Go.
Model 3 has 2000 miles on the clock and it’s fuel cost total £2.
We draw a kilowatt a week from the grid in late spring/summer/early autumn and run the rest of the year on off-peak juice stored in the Powerwalls. We’ve had about 20 brief power cuts and noticed none of them. The PW’s and panels just keep on running.
Not sure I’d want to be able to power the house from the car though or give control of my kit to Octopus or Tesla.
one day the PHEV will be replaced with a second EV. I now have the capacity to cope with it.

 

[Glan gluaisne]

The key is in understanding "is it worth it?", from a personal perspective. In financial terms, the system is very unlikely to ever pay for itself in reduced energy cost. Right now, even the very cheapest battery storage systems cannot break even, just on better utilisation of PV generation or making better use of off-peak domestic tariff rates. The problem is that the return on investment tends to be between about 15 and 25 years in practice, and in all probability some parts of the system will have failed and needed replacement before then, so, in effect, the investment is unlikely to ever be recovered that way.

That's not the only "is it worth it?" aspect though, there are at least two others. The obvious one is that some are prepared to pay a premium in order to reduce their personal CO2 emissions, so this has some value to them (the question is "how much value?"). A second reason is to provide back up power for times when the grid goes down. This depends where you live, but here we tend to get several power cuts a year, so there is a value to us in having a straightforward back up system. My assessment of that value is that it's worth the cost of a small (say 2kVA) generator, together with a changeover switch/relay and associated wiring.

For background, we have a fairly large in-roof PV system, installed instead of the roof covering when we built the house. Our total CO2 emissions are already negative (-0.9 tonnes of CO2 per year) because of this, including accounting for our grid electricity import. This means that, for us, any CO2 reduction would just be further offsetting that generated by other households (which is a valid thing to do). In terms of cost saving, the way I have worked this out is to assess the value of the electricity saved each year from any battery system. Our house is all-electric, electric heating, water heating, etc. The net saving on our electricity bill from having a battery, in addition to our 6 kWp plus PV system would be around £150 to £200 per year, under ideal conditions, roughly our bill would drop by about a 1/3rd . This might give an idea as to the likely cost saving, versus the capital expenditure.

 

[pgkevet]

I keep looking at the idea of solar PV but with no cell service there is no chance of a smart meter and I'm unaware of any grid export without it now?? Despite being very rural we have few power outages that last longer then the time to wheel the genny out of the barn and hook it up. I fire it up every few weeks to check it's working and recharge it's starter battery but haven't used it for power for 2 years - essential though for the borehole pump and freezers if there is a major outage. How long does a powerwall last before it's capacity drops to pathetic - 80% at 10 years (warranty), useless by 15 years and a cost to remove and dispose? What happens with old solar panels at the end of life?

 

[Glan gluaisne]

I keep looking at the idea of solar PV but with no cell service there is no chance of a smart meter and I'm unaware of any grid export without it now?? Despite being very rural we have few power outages that last longer then the time to wheel the genny out of the barn and hook it up. I fire it up every few weeks to check it's working and recharge it's starter battery but haven't used it for power for 2 years - essential though for the borehole pump and freezers if there is a major outage. How long does a powerwall last before it's capacity drops to pathetic - 80% at 10 years (warranty), useless by 15 years and a cost to remove and dispose? What happens with old solar panels at the end of life?

Being reliant on a borehole for water, and an electrically powered and pumped sewage treatment system, is one reason that I also keep a small generator on standby! Like you, power cuts tend to be frequent, but usually for no more than an hour or two, and we can usually manage with the water stored in the pressure vessel for a short time (as long as we don't try to take a shower or bath during a power cut).

In our case, the end-of-life disposal problem from the PV panels is no worse than that from any other roofing material, as our roof covering on one side is actually the panels themselves, we have no slates underneath them (that saved a couple of thousand on the price of the install).

There are no subsidies available at all now, only actual export payments at pretty much the mean wholesale electricity price, although it is still just about possible to make a PV system pay for itself, even without these payments. Depends a lot on how well you can utilise PV electricity to replace grid import, and also very much on how good a deal you can get on a PV system. I know of a few largely DIY installed systems that have come in at an installed cost of less than half that being quoted by some installers, so it can be worthwhile with a bit of shopping around, even if an electrician is used for the final connection side (highly recommended).

 

[pgkevet]

I'm beyond the age where there is any sense in climbing on my own roof even with scaffold towers adding to the cost - it's a high steep roof and very prone to Welsh moss growth. If the planners didn't mind it'd make more sense to do a ground level install along the (instead of) the fence to my nearest field.......closest point to the consumer unit would be a 60 meter trench.....

 

[Dilly]

Glan is quite right. The days of payback are gone. My original panels will have paid for themselves this year (year 6). The rest of my kit won’t during my lifetime. To be honest I’m not that bothered. I could afford to do it and I felt it was the right thing to do.
I do however get the satisfaction of seeing next no grid draw during daylight hours and running only on off-peak electricity when needed.
I do enjoy driving the car with next to no fuel cost. I get the ‘Tesla smile’ and a smug grin

 

[MrBadger]

I've been Researching and wi Dow shopping solar PV and powerwalls for a week or two now. I have emailed the tesla certified installers for quotes (new year and Xmas holidays) so will expect more responses in the coming days.
I live in Rugby West midlands with a southish facing roof (picture attached)

A much wider selection of battery solutions than just Powerwall. Some of them are modular so can be easily resized if requirements change and most significantly cheaper. I installed a 7kWh system for £3k - just waiting to find an electrical willing to make the final connection and return to undertake the tests and signoff for the final paperwork - I'm not looking very hard.

A south facing roof is a bit of a misnomer. Whilst it will give better peak power, an east and west facing roof will give a longer period of useful power. Also shading of any type, including aerial, chimney, dormer, telegraph line etc can have a huge impact on generation although this can be mitigated against by different methods and/or products.

 

[ACarneiro]

I echo most of the comments here.
I have a 9.6kWp solar system and 2 Powerwalls.
It's a significant investment (it was closer to the £25k mark) which will never see a proper monetary return.
What @Glan gluaisne and @Dilly said, though, is very true: stuff has other value than just monetary.
There is the carbon footprint reduction t consider and especially the smugness of knowing your house and your car are running on sun (in the summer).
I also like knowing that my batteries are charged at 5p/kWh in the winter time which is not only MUCH cheaper than any other E7 tariff I ever found but generally coincides with a lower carbon intensity time for electrical generation, thus further offsetting some of the carbon footprint.
If you're money-minded, forget about the batteries. If money is not the primum movens then it's definitely worth considering.

 

[Dilly]

A much wider selection of battery solutions than just Powerwall. Some of them are modular so can be easily resized if requirements change and most significantly cheaper. I installed a 7kWh system for £3k - just waiting to find an electrical willing to make the final connection and return to undertake the tests and signoff for the final paperwork - I'm not looking very hard.

A south facing roof is a bit of a misnomer. Whilst it will give better peak power, an east and west facing roof will give a longer period of useful power. Also shading of any type, including aerial, chimney, dormer, telegraph line etc can have a huge impact on generation although this can be mitigated against by different methods and/or products.

I have my original 28 panels south facing on my main roof. I added 5 south facing and 8 west facing panels on my annex. Those 13 can’t export. The 8 make a big difference putting a couple of Kw into the system before the sun goes down.
I’m hampered by tall trees on my southern boundary but they form a good privacy/noise/wind barrier. It’s a trade off.
Today Is the first day since November that I’ve have peak input over 2Kw. In summer, it’s an easy 9 or 10Kw
Winter days can be less than 1Kwh all day but in summer I’ve had over 60Kwh!

 

[Yachtsman]

I'm in a similar position to the OP, however I'm not in my forever home and anticipate downsizing in the next 10 years or so, hence the following question.
What percentage of the initial outlay do you think can realistically be added to the value of the property, should you decide to sell?
Thanking all contributors in anticipation.

 

[browellm]

I have wanted to go solar for years but the capital outlay put me off (always another priority etc.).

I've recently gone with the E.On 3 year 0% credit option to get solar and an 8kW GivEnergy battery system. The pricing seems really good too. I costed up all the materials wholesale and they are not making a huge amount on supply/install.

 

[Dilly]

I'm in a similar position to the OP, however I'm not in my forever home and anticipate downsizing in the next 10 years or so, hence the following question.
What percentage of the initial outlay do you think can realistically be added to the value of the property, should you decide to sell?
Thanking all contributors in anticipation.

I genuinely have no idea. In the next ten years I’m sure it will make a noticeable difference, particularly as EV’s and climate change desire gains popularity

 

[Glan gluaisne]

I'm in a similar position to the OP, however I'm not in my forever home and anticipate downsizing in the next 10 years or so, hence the following question.
What percentage of the initial outlay do you think can realistically be added to the value of the property, should you decide to sell?
Thanking all contributors in anticipation.

That's a real challenge! I've heard of houses being devalued by having solar panel installations, and have a feeling they add no value to most properties for many prospective purchasers. This seems bizarre on the face of it, but I know of a couple of people who removed their PV systems when they sold their homes because they found that buyers weren't keen on having them.

As another data point, when we completed our self build in 2016, we had it valued, really just so we had an idea as to whether self-build had saved us much money (they answer was "not a lot"). The valuer we had around (a RICS chap) reduced his value by 5% because it was a passive house (i.e. very well insulated, air tight and effectively zero energy over the course of a year). I challenged him on this, and his reply was that "eco houses" were a niche market, and because of that there were fewer buyers prepared to purchase one, and fewer interested buyers meant reducing the value.

This may change as people start to place a higher value on house running costs and damage to the environment, but right now I suspect it's still the case that things like solar panels and battery storage systems are seen as a liability, rather than a benefit, by many. It's still the "bling" that sells houses and makes them more valuable, stuff like decent kitchens and bathrooms are much higher on the value scale than anything that reduces running costs.

 

[ACarneiro]

That's a real challenge! I've heard of houses being devalued by having solar panel installations, and have a feeling they add no value to most properties for many prospective purchasers. This seems bizarre on the face of it, but I know of a couple of people who removed their PV systems when they sold their homes because they found that buyers weren't keen on having them.

As another data point, when we completed our self build in 2016, we had it valued, really just so we had an idea as to whether self-build had saved us much money (they answer was "not a lot"). The valuer we had around (a RICS chap) reduced his value by 5% because it was a passive house (i.e. very well insulated, air tight and effectively zero energy over the course of a year). I challenged him on this, and his reply was that "eco houses" were a niche market, and because of that there were fewer buyers prepared to purchase one, and fewer interested buyers meant reducing the value.

This may change as people start to place a higher value on house running costs and damage to the environment, but right now I suspect it's still the case that things like solar panels and battery storage systems are seen as a liability, rather than a benefit, by many. It's still the "bling" that sells houses and makes them more valuable, stuff like decent kitchens and bathrooms are much higher on the value scale than anything that reduces running costs.

On this particular subject I said before and I'll say it again. The mind absolutely boggles....

 

[Obliter8]

Not sure anyone has posted it, but I'm about to pull the trigger on Powerwall + Tesla Energy Plan. I have an existing (2013) solar array, which has just about paid for itself.

The Tesla Energy Plan actually looks like saving us ~£500/yr as it's a flat 8p/kWh rate, with no standing charge - a huge saving. If that stays true, that's a 20-year payback window, but as others have said, there's more to it than just the financials

 

[Dilly]

Just to add some context to the conversation.
In 2020, we used 9500Kwh on home and cars. Of that just under 2200Kwh came from the grid and of that just 200Kwh was peak draw.
Much of that peak draw has now been reduced for the future. Some was pre Octopus Go tariff and a spot of tweaking on the Powerwalls reduced balancing draw from around 1Kwh per day down to about 1Kwh every 6-7 days. The last three quarters had just 24Kwh peak draw in total.
8500Kwh was generated and about 1000Kwh exported.

 

[Yachtsman]

That's a real challenge! I've heard of houses being devalued by having solar panel installations, and have a feeling they add no value to most properties for many prospective purchasers. This seems bizarre on the face of it, but I know of a couple of people who removed their PV systems when they sold their homes because they found that buyers weren't keen on having them.

As another data point, when we completed our self build in 2016, we had it valued, really just so we had an idea as to whether self-build had saved us much money (they answer was "not a lot"). The valuer we had around (a RICS chap) reduced his value by 5% because it was a passive house (i.e. very well insulated, air tight and effectively zero energy over the course of a year). I challenged him on this, and his reply was that "eco houses" were a niche market, and because of that there were fewer buyers prepared to purchase one, and fewer interested buyers meant reducing the value.

This may change as people start to place a higher value on house running costs and damage to the environment, but right now I suspect it's still the case that things like solar panels and battery storage systems are seen as a liability, rather than a benefit, by many. It's still the "bling" that sells houses and makes them more valuable, stuff like decent kitchens and bathrooms are much higher on the value scale than anything that reduces running costs.

I'd heard similar stories in recent years & wondered whether the situation had changed with the progressive uptake of EVs and growing interest in the environment.
Like you said Glan it doesn't really make sense, the new owner will get the benefits without the high initial costs and general disruption during installation and balancing performance.

 

[acentre]

Hi everyone,
So as the title suggests. I've been Researching and wi Dow shopping solar PV and powerwalls for a week or two now. I have emailed the tesla certified installers for quotes (new year and Xmas holidays) so will expect more responses in the coming days.
I live in Rugby West midlands with a southish facing roof (picture attached)
I also have a Tesla model 3 performance.
I wanted to ask current solar and powerwall owners what their experience has been like with the whole setup? I'm guessing this is a £15k plus investment so not an easy pill to swallow but with ev charging, immersion water heater and octopus agile might be worth it?

Thanks
View attachment 623980

I installed a powerwall and 4 kw of panels fall of 2017 and love the power backup when we lose power...working flawless. Only problem when 2 feet of snow have to be cleared from the panels, but I just use the grid then... prices have never been lower for a system.
enjoy!

 

[Fly.guy]

Not sure anyone has posted it, but I'm about to pull the trigger on Powerwall + Tesla Energy Plan. I have an existing (2013) solar array, which has just about paid for itself.

The Tesla Energy Plan actually looks like saving us ~£500/yr as it's a flat 8p/kWh rate, with no standing charge - a huge saving. If that stays true, that's a 20-year payback window, but as others have said, there's more to it than just the financials

I looked into this recently and the fact that you have to give up the deemed 50% export payment from the PV system pretty much scuppered it making sense financially.

If you have PV, a PW and Agile your pretty much able to run off the lowest carbon electricity possible and do not impose a drain on the grid at peak times as it is.