Solar Panels UK - is it worth it?

[yessuz]

the ACTUAL question would be - when will it make sense for people to invest into heating insulation :-]

in a country where temperatures almost never fall below 0 C, with proper heating systems and really good insulation, you probably would never use anything for heating

 

[Peter 224]

the ACTUAL question would be - when will it make sense for people to invest into heating insulation :-]

in a country where temperatures almost never fall below 0 C, with proper heating systems and really good insulation, you probably would never use anything for heating

Agreed, but...
this only really works on new builds and then only if the builders actually do their job properly. They are also horrible to live in, according to someone I know who went down this route, as they are effectively sealed boxes with no natural ventilation. It almost caused a divorce and they sold up and moved.

We have a largish 5 bed detached house, built in the early 1980s and have managed to get it to EPC B - 81. Going further has no payback. Why? Because the floor slab sits on the ground, uninsulated and the rooms are not tall enough to insulate internally.

Without a total change in the way we live we need a mix of energy sources and without tidal and nuclear we are stuck burning natural gas.

 

[Yachtsman]

I think we're saving far more avoiding imports than what we might gain from exporting more. Currently 16p/kWh but it looks like we'll be on >30p/kWh within 12 months. This is were I expect us to gain the most.

Where are you getting those rates from? Are you on a FIT contract, that would explain your numbers.
I’ve been looking at SEG payments & they are abismal, average about 3p kWh.

 

[yessuz]

Agreed, but...
this only really works on new builds and then only if the builders actually do their job properly. They are also horrible to live in, according to someone I know who went down this route, as they are effectively sealed boxes with no natural ventilation. It almost caused a divorce and they sold up and moved.

We have a largish 5 bed detached house, built in the early 1980s and have managed to get it to EPC B - 81. Going further has no payback. Why? Because the floor slab sits on the ground, uninsulated and the rooms are not tall enough to insulate internally.

Without a total change in the way we live we need a mix of energy sources and without tidal and nuclear we are stuck burning natural gas.

I am in a 6 year old house so I tend to disagree.

You can always have a better house insulation from the outside + loft & roof has quite a lot of room for improvement

Please correct me if I am wrong, but I think all new houses have to be A, while in nordic countries it is A+

 

[init6]

Where are you getting those rates from? Are you on a FIT contract, that would explain your numbers.
I’ve been looking at SEG payments & they are abismal, average about 3p kWh.

I think he's paying 16p/kWh for electricity coming into the house.

 

[Zakalwe]

Pp

I had a quote from one company in late november 2021
My house is east/west facing, 3 bed detached 6 year old property (standard project). Option for east/west Velux option is calculated in (as we are exploring this option).

Quote attached.

if I would like to add a battery, they ciuod also install a Solax 5.8KW battery with battery management system and charge controller with 10 years warranty for an additional £4,995.00.

In comparison I have fitted a 5.18 kWh system (14 x 370 Watt panels integrated into the roof, so the panels are flush with the tiles), a 5kWh hybrid inverter, an 8.2kWh battery and all the various isolators, EM115 and assorted gubbins. The panels are JA Mono MBB, the inverter and battery are both Givenergy.
The total cost was £10.5K inc VAT.

Your quote looks kinda pricey to me.

 

[Yachtsman]

Pp


In comparison I have fitted a 5.18 kWh system (14 x 370 Watt panels integrated into the roof, so the panels are flush with the tiles), a 5kWh hybrid inverter, an 8.2kWh battery and all the various isolators, EM115 and assorted gubbins. The panels are JA Mono MBB, the inverter and battery are both Givenergy.
The total cost was £10.5K inc VAT.

Your quote looks kinda pricey to me.

Mines pricey than yours too but I put that down to me choosing SolarEdge system, known to be 10% more than say givenergy. I like the flexability, excellent control via the app etc.
I’m not interested in ROI & no one should if thinking of a PV system unless the government start giving out significant grants.

 

[GlynG]

There are so many choices of solar panels and storage solutions its hard to compare like for like or to get a price you feel is competitive as everyone seems to be offering different hardware, so at the end of the day its a gut choice.
Battery storage - no matter how big a battery KWs wise it is never enough, I have 13.5Kws and if there is no solar generation I just about squeeze 24hrs running the house for free but you have to be aware of the limitation on the KWs output the battery system you choose can output, mine is 6kws, so if i have the kettle on (3KWs) i make sure i don't also have the iron on and the oven too - i try to keep the max draw under 5Kws otherwise although i have the storage if I exceed the 6Kws its drawing from the grid the excess - so I'm paying for it.
As for battery life and guarantees - I don't think they are worth the paper they are written on because no one really knows just how long the batteries will remain serviceable, what capacity they will loose over a long term, what output reductions will take place as they age, the longevity of the electronics controlling them - the BMS reliability or even the inverter to convert back to 240volts.
My battery system is 3x 4.5kw Solax Tripple power, they claim a 6000 cycle lifespan or 10 years- so that's 6000 times charging from 10% up to 100%, however if the battery is half charged and we get plenty of sun then to fully charge counts as half a cycle - Its impossible to be able to monitor or manage that in order to issue a valid claim as the cycles are not counted - and the guarantees are not so good if you read the small print as they guarantee a certain amount of capacity at certain points in their age - cant remember all the details but if my batteries have more than 50% capacity at 10 years age then its performed to spec and therefore no claim - despite I only have half the capacity as new.

I'm looking at it all as a bit of a game, if i get 10 to 15 years of reasonable capacity then hopefully battery technology will have moved on and there will be something much better to replace what i have, the system will have paid me back by then so spending another £5K to £10K at that point will be fair game to me.
The panels are LG Neon Rs and guaranteed 25 years in construction and output at 92% of new capacity at the 25yr mark - the main inverter has 20 years guarantee - so panels will be fine and perhaps I will need to replace the batteries and both main inverter and battery inverter, but by then i will be in my late 80s - so will I do it - probably not.
Overall I think in the long term the system will have saved me a shed load of money and although the FIT payments will cease in 2038 and therefore the savings will reduce drastically I feel its been good value for money.

The biggest issue for Solar and battery storage is the rather poor electrically experienced installers and their rather poor diagnostic skills, they struggle to initially install correctly and fault finding is usually left to the system owner to pick up that something isn't right or the system isn't optimal, - and because as a lay person you cant talk their language in electrical engineering you rely on their skills to interpret what your telling them - and often there isn't a financial incentive for them to get too involved, There is big money in installing but not in after service or warranty claims - so be prepared to learn all you can on how your system generates, how it performs, take readings of panel outputs on the apps you have to control your system and how well your battery systems power your house - this way you will notice when something isn't right.

 

[PITA]

There are so many choices of solar panels and storage solutions its hard to compare like for like or to get a price you feel is competitive as everyone seems to be offering different hardware, so at the end of the day its a gut choice.
Battery storage - no matter how big a battery KWs wise it is never enough, I have 13.5Kws and if there is no solar generation I just about squeeze 24hrs running the house for free but you have to be aware of the limitation on the KWs output the battery system you choose can output, mine is 6kws, so if i have the kettle on (3KWs) i make sure i don't also have the iron on and the oven too - i try to keep the max draw under 5Kws otherwise although i have the storage if I exceed the 6Kws its drawing from the grid the excess - so I'm paying for it.
As for battery life and guarantees - I don't think they are worth the paper they are written on because no one really knows just how long the batteries will remain serviceable, what capacity they will loose over a long term, what output reductions will take place as they age, the longevity of the electronics controlling them - the BMS reliability or even the inverter to convert back to 240volts.
My battery system is 3x 4.5kw Solax Tripple power, they claim a 6000 cycle lifespan or 10 years- so that's 6000 times charging from 10% up to 100%, however if the battery is half charged and we get plenty of sun then to fully charge counts as half a cycle - Its impossible to be able to monitor or manage that in order to issue a valid claim as the cycles are not counted - and the guarantees are not so good if you read the small print as they guarantee a certain amount of capacity at certain points in their age - cant remember all the details but if my batteries have more than 50% capacity at 10 years age then its performed to spec and therefore no claim - despite I only have half the capacity as new.

I'm looking at it all as a bit of a game, if i get 10 to 15 years of reasonable capacity then hopefully battery technology will have moved on and there will be something much better to replace what i have, the system will have paid me back by then so spending another £5K to £10K at that point will be fair game to me.
The panels are LG Neon Rs and guaranteed 25 years in construction and output at 92% of new capacity at the 25yr mark - the main inverter has 20 years guarantee - so panels will be fine and perhaps I will need to replace the batteries and both main inverter and battery inverter, but by then i will be in my late 80s - so will I do it - probably not.
Overall I think in the long term the system will have saved me a shed load of money and although the FIT payments will cease in 2038 and therefore the savings will reduce drastically I feel its been good value for money.

The biggest issue for Solar and battery storage is the rather poor electrically experienced installers and their rather poor diagnostic skills, they struggle to initially install correctly and fault finding is usually left to the system owner to pick up that something isn't right or the system isn't optimal, - and because as a lay person you cant talk their language in electrical engineering you rely on their skills to interpret what your telling them - and often there isn't a financial incentive for them to get too involved, There is big money in installing but not in after service or warranty claims - so be prepared to learn all you can on how your system generates, how it performs, take readings of panel outputs on the apps you have to control your system and how well your battery systems power your house - this way you will notice when something isn't right.

Agreed

Also, we have 27kWh of battery storage, and I really need 40kWh.... but ideally 55kWh as that would also allow for decent blackout cover.

Storage is just like Solar Panel power... you can never have too much.

 

[ACarneiro]

Agreed

Also, we have 27kWh of battery storage, and I really need 40kWh.... but ideally 55kWh as that would also allow for decent blackout cover.

Storage is just like Solar Panel power... you can never have too much.

Wouldn't it be grand if our Teslas had the ability to "join forces" with the powerwalls in a V2G-like capability to power our own homes?

 

[Mrklaw]

Anyone have a ‘free’ PV setup? I have one that lets us use the electric but the installer gets the exports. Do you know if we’d be allowed to install a battery - it would just be ‘using’ more of the generated amount. I assume they make some money from assumed export anyway?

 

[PITA]

Wouldn't it be grand if our Teslas had the ability to "join forces" with the powerwalls in a V2G-like capability to power our own homes?

Yes actually, it would be very good.

A while back I looked into this, but I think Tesla don't want to do it for some reason.

I think the answer is quite technical, but something along the lines of the car would need it's own inverter... to convert back to AC Power. This inverter would be heavy, take up a lot of space inside the car, and would be a point of failure risk... Also, having the car cycle the battery pack a lot more, so maybe Warranty would be an issue.

The other option, is to have the Inverter built into the home wall charger, but then you're transferring very high DC voltages across a cable into your house... This then becomes a safety risk and the internal battery wiring may need to be changed somehow?

Don't know... all sounds great, but I think Tesla would rather keep the battery packs separate. ie, using the Tesla Powerwall 2 for your house...

There's a thing called a WALLBOX QUASAR CHARGER which costs about £10,000 .... which claims to do Vehicle to Home... but I don't know anything about it...

EDIT : Actually while writing this I did a quick Google search and came across this information. I might look into this more, as it might allow for swapping Power from the car to our Powerwalls... that would be brilliant.

>>>>> Some info

Quasar is the first bidirectional charger for home use. It allows you to charge and discharge your electric vehicle so you can use your car battery to power your home or the grid. With Quasar, your EV energy goes beyond driving.

Charger: DC
Connector: CHAdeMO
Charging mode: Mode 4
Dimensions (without cable): 350x350x150 mm (without cable)
Weight: 15,5kg (without cable), 22 kg (with cable)
Cable length: 5m
Maximum Power* (charge mode): 7,4 kW
Maximum Power* (discharge mode): 7,4 kW
Maximum AC current: from 6 A to 32 A
Maximum DC current: up to 17A
*Final charging power depends on the charger settings, installation and vehicle.

 

[RedMod3]

Does anyone have a Powerwall without PV or other heat source?
What would be the total cost of a Powerwall including installation?
I’m considering a battery option, charged at off-peak to reduce the cost of using peak power during the daytime.
As my current peak demand is about 12 KWh per day I thought one Powerwall may be viable.
I’m on Octopus Go tariff which is due to increase from 5p/KWh to 7.5p and 13.5p to 30.77p peak.

Don't forget, if you just get a Powerwall installed, you will pay 20% VAT. If you get PV at the same time, you could get 5% VAT on the whole installation.

 

[dakaix]

Don't forget, if you just get a Powerwall installed, you will pay 20% VAT. If you get PV at the same time, you could get 5% VAT on the whole installation.

To qualify that, the 5% VAT rate is only where the materials are less than 60% of the total amount. For a PowerWall (or similar large capacity battery) it is highly unlikely that there are enough installation/labour costs to make up 40%.

You will also be eligible to get the reduced rate on the products if the total cost of them (not including VAT) is not over 60% of the cost of the installation of the products (not including VAT).

If your products cost more than 60% of the installation, you’ll only be entitled to the reduced rate on the installation.

Example
The installer is charged £3,500 for solar panels and battery (excluding VAT) and charges you £5,385 (excluding VAT) for the installation. As the value of the materials (the solar panels and the battery) is 65% of the total cost to you for both the materials and installation, it is over the 60% threshold. This means the installer will need to charge VAT for the solar panel and battery at the standard rate and the installation will qualify for the reduced rate of 5%.

Source: Tax on shopping and services

 

[Avendit]

Agreed, but...
this only really works on new builds and then only if the builders actually do their job properly. They are also horrible to live in, according to someone I know who went down this route, as they are effectively sealed boxes with no natural ventilation. It almost caused a divorce and they sold up and moved.

I think if you get to this stage, you should be installing MVHR? Lots of fresh air, no penalty for drafts?

What I'm not sure of is how to measure how close we are getting to needing that as we upgrade, seal and insulate. I doubt any of the 'air quality' sensors measure the right thing, as they are all about CO and particulate content. I'm not sure what leads to the sealed box feeling that your friend experienced that could be measured?

Back on topic, so.energy rep coming to do an installation survey today, am pretty excited! Lets see how many panels he can squeeze on our roof.

 

[PITA]

I think if you get to this stage, you should be installing MVHR? Lots of fresh air, no penalty for drafts?

What I'm not sure of is how to measure how close we are getting to needing that as we upgrade, seal and insulate. I doubt any of the 'air quality' sensors measure the right thing, as they are all about CO and particulate content. I'm not sure what leads to the sealed box feeling that your friend experienced that could be measured?

Back on topic, so.energy rep coming to do an installation survey today, am pretty excited! Lets see how many panels he can squeeze on our roof.

Except North Facing... get as many panels on as possible, and as higher capacity rating as you can afford, and your DNO will allow

It only makes financial sense, in that you don't then have to think 'what if I'd had more...'

Don't think I've ever met or read about someone who wished for less panels...

 

[Avendit]

Except North Facing... get as many panels on as possible, and as higher capacity rating as you can afford

The peak of our house runs north west to south east, so we have 1 side that faces south west. My assumption is that will be filled to the max and nothing on the north east facing side. We are in Edinburgh, so in the summer the north east side does get good light, but I think its probably not overall worth adding anything to.

I'd assume a DNO cap at 4.8kw output, but I'm happy clipping the peak output for additional generation the rest of the day. If you generate more, but use it, is that OK? ie could I generate 6kw, use 2 and export 4? Cause I can almost definitely manage that .

Will see what the guy says.

 

[PITA]

The peak of our house runs north west to south east, so we have 1 side that faces south west. My assumption is that will be filled to the max and nothing on the north east facing side. We are in Edinburgh, so in the summer the north east side does get good light, but I think its probably not overall worth adding anything to.

I'd assume a DNO cap at 4.8kw output, but I'm happy clipping the peak output for additional generation the rest of the day. If you generate more, but use it, is that OK? ie could I generate 6kw, use 2 and export 4? Cause I can almost definitely manage that .

Will see what the guy says.

Well, our house has 3 roof angles. It isn't big, but just an awkward shape.

Originally our Solar Panel guys suggested we put panels only on the SW & SE sides. Amounting to 3.2kWp

So I said, what about the back of the house, on the NE side... we can get another 10 Panels on that. They we're VERY reluctant to do it.

I since found out, it's because they just wanted a quick sale. 3.2kWp doesn't need DNO approval. But significantly over that, does need DNO approval.

So I insisted we put up another 10 panels... and I waited patiently weeks for the approval.

Very glad I did, in Summer those 10 extra panels catch all the Sunrise light and fills our Powerwalls by 11am. Massive benefit.

Also, during mixed weather, we catch all the early sunlight before the clouds set in.

In Winter or overcast light, as the sunlight is diffused through the clouds, it means ALL the panels get the same power, regardless of which direction they face.

So in the end it was well worth it.

 

[Yachtsman]

Well, our house has 3 roof angles. It isn't big, but just an awkward shape.

Originally our Solar Panel guys suggested we put panels only on the SW & SE sides. Amounting to 3.2kWp

So I said, what about the back of the house, on the NE side... we can get another 10 Panels on that. They we're VERY reluctant to do it.

I since found out, it's because they just wanted a quick sale. 3.2kWp doesn't need DNO approval. But significantly over that, does need DNO approval.

So I insisted we put up another 10 panels... and I waited patiently weeks for the approval.

Very glad I did, in Summer those 10 extra panels catch all the Sunrise light and fills our Powerwalls by 11am. Massive benefit.

Also, during mixed weather, we catch all the early sunlight before the clouds set in.

In Winter or overcast light, as the sunlight is diffused through the clouds, it means ALL the panels get the same power, regardless of which direction they face.

So in the end it was well worth it.

My house is similar to yours with 3 roofs, SW, SE & NE, the SW taking 5 x 400Wp panels, with the NE taking 4 x 400Wp, generating almost 1000kWh/ year almost 30% of the total generation so well worth including. I’m my case it was all 3 installers I contacted that suggested utilising the NE.
I’m waiting for my on site survey & DNO approval at the mo.

 

[PITA]

This is what I love...

Right now I'm sat in the living room, in January, with our Heat Pump heating on. It's 22.5 degrees toasty... and 5 degrees outside.

Our Solar Array is producing 1.3kW of power... but our house demand is only 1.9kW... with 600W being supplimented from our Powerwall storage batteries (filled with cheap overnight electric at 5p).

No 'peak rate' Grid...

It really is a good setup.