Speak EV - Electric Car Forums banner

1 - 20 of 23 Posts

·
Registered
Joined
·
57 Posts
Discussion Starter #1
Hi folks. In the early stages of thinking about getting solar and budgeting. Just wondering what a good fair price would be and what people have paid recently? Looking at a typical 4kw system, probably on 2 aspects (S+W) no shading.

Wondering about a battery but seems high cost for little return. Plus I have an EV and would think about hot water diverter so probably better putting excess into those than paying £1k per kWh for a battery.

Eon prices seem pretty reasonable, anyone used them?
 

·
Registered
Joined
·
355 Posts
Not sure of latest prices but if you get no up-to-date response here try the appropriate sub-forum on MSE, they've got quite a few clued up people. The Navitron and Green Building Press forums are also helpful.

Mine was £6K but that was 7 years ago: had a hot water diverter too but you should do better than that. A Project Solar quote would make you wince then laugh. I agree on the battery front: you've already got a mobile one anyway(!), but costs need to come down a bit more.
 

·
Registered
Joined
·
3,860 Posts
Hi folks. In the early stages of thinking about getting solar and budgeting. Just wondering what a good fair price would be and what people have paid recently? Looking at a typical 4kw system, probably on 2 aspects (S+W) no shading.

Wondering about a battery but seems high cost for little return. Plus I have an EV and would think about hot water diverter so probably better putting excess into those than paying £1k per kWh for a battery.

Eon prices seem pretty reasonable, anyone used them?
So I guess you need comparison prices for two off 2kW systems since your South and West systems will be largrly independent.
 

·
Registered
Joined
·
1,202 Posts
So I guess you need comparison prices for two off 2kW systems since your South and West systems will be largrly independent.
Not really, you just need a dual-mppt inverter, and possibly slightly higher costs for scaffolding.

As a price point, our 4kWp east\west install was £4.5k 5 years ago. This included a solar iboost for water heating. Panels have got cheaper and more efficient since then, but install costs are the same. I would recommend an Eddi these days rather than an iboost, along with a Zappi for charging. Zappi and Eddi talk to each other to work out the best way to use the excess PV.
 

·
Registered
Joined
·
57 Posts
Discussion Starter #5
Thanks. About £4.5k is the price I seem to be seeing (thanks Sue! Looked at MSE) about which sounds really very reasonable. Scaffolding could be my complication with two aspects but would hope not too much more. I've a vid call with Eon booked next week to see what they quote.
 

·
Registered
Joined
·
1,563 Posts
Hi folks. In the early stages of thinking about getting solar and budgeting. Just wondering what a good fair price would be and what people have paid recently? Looking at a typical 4kw system, probably on 2 aspects (S+W) no shading.

Wondering about a battery but seems high cost for little return. Plus I have an EV and would think about hot water diverter so probably better putting excess into those than paying £1k per kWh for a battery.

Eon prices seem pretty reasonable, anyone used them?
Dont forget to consider Octopus Energy Go or Agile tariff and of course a smart charger like Ohme which is half price via Octopus.
Need a smart meterfor the Go or Agile, but can use their Tracker tariff if lockdown prevents you getting a smart meter for some months.
Battery solution is still high price and more of a nice to have than a ROI decision.
2 aspects on a roof shouldnt make much difference to cost.
We had dual aspects installed, but it does depend on roof layout and heights involved.
Not sure where you are in the UK, but worth trying some larger installers for quotes like Joju Solar UK Solar energy, Battery storage & EV charging experts - Joju Solar and Spirit Energy Spirit Energy | Solar PV & Battery Installers
Another one recently come across is Tanjent Solar and Battery Home Page - Tanjent Energy
 

·
Registered
Joined
·
57 Posts
Discussion Starter #7
Dont forget to consider Octopus Energy Go or Agile tariff and of course a smart charger like Ohme which is half price via Octopus.
Need a smart meterfor the Go or Agile, but can use their Tracker tariff if lockdown prevents you getting a smart meter for some months.
Battery solution is still high price and more of a nice to have than a ROI decision.
2 aspects on a roof shouldnt make much difference to cost.
We had dual aspects installed, but it does depend on roof layout and heights involved.
Not sure where you are in the UK, but worth trying some larger installers for quotes like Joju Solar UK Solar energy, Battery storage & EV charging experts - Joju Solar and Spirit Energy Spirit Energy | Solar PV & Battery Installers
Another one recently come across is Tanjent Solar and Battery Home Page - Tanjent Energy

Thanks, yes already on Agile. So cheap it almost destroys any financial case for solar! I agree re battery, think a more cost effective thing that do would be to divert excess to my Zoe or to hot water for now. Amazing that we're getting car battery costs down to £100 per kWh but for home storage it's closer to £1k per kWh. Very useful to hear about the diff aspects thanks
 

·
Registered
Joined
·
1,563 Posts
Thanks, yes already on Agile. So cheap it almost destroys any financial case for solar! I agree re battery, think a more cost effective thing that do would be to divert excess to my Zoe or to hot water for now. Amazing that we're getting car battery costs down to £100 per kWh but for home storage it's closer to £1k per kWh. Very useful to hear about the diff aspects thanks
Diverter does help get the export numbers down. We have an Immersun, superceeded by Eddi.
I use it to divert to hot water, far infra red heater panels and/or underfloor electric in our office.
Still cant use all the energy generated during summer months.
Since we got a Powerwall2 before Xmas it laterly charges the PW2 up, then the excess switches to hot water.
Another useful product is ecopush smart sockets.
Been using a couple of those to use cheap Agile recently, especially during plunges.

Car batteries are better value than storage solutions and makes me wonder why more dont get a used leaf and get v2g going. Think a lot of interesting changes over next year in the UK for sure.
 
  • Like
Reactions: Tony1

·
Registered
Joined
·
897 Posts
Car batteries are better value than storage solutions and makes me wonder why more dont get a used leaf and get v2g going. Think a lot of interesting changes over next year in the UK for sure.
I think the issue would be a V2G capable charger might cost the same as a used Leaf, so adds a lot of additional expense on top.
 

·
Registered
Joined
·
143 Posts
If you have gas then a hot water diverter will actually cost you money. Each kWh you export will gain you 5.5p which you would lose if you diverted it. Gas only costs 2.5p per kWh. Diverters (just about) made sense for people getting deemed export payments but are not a good investment now that export must be metered.

My 3.42kWp array cost £4k in 2017 with a dual string inverter. They didn't use scaffolding though. I'd hope you could get 4kWp for around or under £4k now.
 

·
Registered
Joined
·
1,202 Posts
If you have gas then a hot water diverter will actually cost you money. Each kWh you export will gain you 5.5p which you would lose if you diverted it. Gas only costs 2.5p per kWh. Diverters (just about) made sense for people getting deemed export payments but are not a good investment now that export must be metered.

My 3.42kWp array cost £4k in 2017 with a dual string inverter. They didn't use scaffolding though. I'd hope you could get 4kWp for around or under £4k now.
It's a good point, definitely worth doing sums if you are planning to claim the SEG. It's not quite so clear cut though. Immersion heaters are 100% efficient, whereas gas boilers much less so. You might end up burning 2kWh of gas to provide 1kWh of heat to the water, in which case the cost would be the same. Also, if you diverted the PV electric you wouldn't be burning fossil fuels.

However on the flip side an Eddi is £400 before install costs, so you may never make back the cost from the savings.

We are on the old 'deemed' export FIT, so we get paid for 50% of export whether we export it or not.
 

·
Registered
Joined
·
1,202 Posts
It's a good point, definitely worth doing sums if you are planning to claim the SEG. It's not quite so clear cut though. Immersion heaters are 100% efficient, whereas gas boilers much less so. You might end up burning 2kWh of gas to provide 1kWh of heat to the water, in which case the cost would be the same. Also, if you diverted the PV electric you wouldn't be burning fossil fuels.

However on the flip side an Eddi is £400 before install costs, so you may never make back the cost from the savings.

We are on the old 'deemed' export FIT, so we get paid for 50% of export whether we export it or not.
Forgot to add; if you plan to claim SEG then you might as well forget the eddi and zappi, export every kWh that you can, earning 5.5p/kWh, then charge the car (and water) overnight (using mostly wind and nuclear) on Octopus GO at 5p/kWh.
 

·
Registered
Joined
·
897 Posts
It's a good point, definitely worth doing sums if you are planning to claim the SEG. It's not quite so clear cut though. Immersion heaters are 100% efficient, whereas gas boilers much less so. You might end up burning 2kWh of gas to provide 1kWh of heat to the water, in which case the cost would be the same. Also, if you diverted the PV electric you wouldn't be burning fossil fuels.

However on the flip side an Eddi is £400 before install costs, so you may never make back the cost from the savings.

We are on the old 'deemed' export FIT, so we get paid for 50% of export whether we export it or not.
Not everyone has gas, so might not be same for everyone.
Also I’d rather use solar to heat my water than gas. It may not make financial sense but personally I’m trying to give up all forms of Dino juice.
 

·
Registered
Joined
·
143 Posts
It's really important to remember that any electricity you export almost exclusively directly offsets additional gas being burned to meet the short term demands on the grid. In addition, because the electricity you export will be used in the local area, you will also prevent the transmission losses from the power station to where the demand is. I'd say it's objectively greener to burn gas and export electricity.

Modern gas boilers are > 85% efficient. Unless you have a really inefficient water heating setup then a solar hot water diverter is almost certainly a false economy. In my house we spend around £50 per year on water heating. It would take 8 years of providing 100% of our hot water for an eddi to break even; that's including our deemed export and ignoring the plumbing changes required.

Do the calculations but be sure to base them on the cost of the gas saved rather than the hypothetical cost of the electricity diverted. And remember, lots of that lovely hot water will be left in the tank to go cold again and will unnecessarily heat your house on sunny days.
 

·
Registered
Joined
·
528 Posts
Not everyone has gas, so might not be same for everyone.
Also I’d rather use solar to heat my water than gas. It may not make financial sense but personally I’m trying to give up all forms of Dino juice.
Good practice. When your gas boiler packs in, replace it with an electric one.
 

·
Registered
Joined
·
57 Posts
Discussion Starter #16
It's a very interesting debate isn't it. We're paying 3.65p gas with octopus so with 92% efficient boiler it's probably about 4p Vs the 5.5p export. From an environmental perspective it's not good that gas is so dirt cheap. I'm tempted by a mixergy tank one day, better insulated and better at only hearing what you need. I've calculated the same that we prob only spend about £50-60 on hot water a year - so I swiftly dismissed the idea of purely solar thermal which I think you get government grant towards.

If you have gas then a hot water diverter will actually cost you money. Each kWh you export will gain you 5.5p which you would lose if you diverted it. Gas only costs 2.5p per kWh. Diverters (just about) made sense for people getting deemed export payments but are not a good investment now that export must be metered.

My 3.42kWp array cost £4k in 2017 with a dual string inverter. They didn't use scaffolding though. I'd hope you could get 4kWp for around or under £4k now.
I'd be delighted to get it for under £4k! Amazing how much the cost has come down in the last decade
 

·
Registered
Joined
·
1,563 Posts
I'd be delighted to get it for under £4k! Amazing how much the cost has come down in the last decade
We paid £8K 5.5 years ago for a dual array 5.6kW system, but it has paid for itself in 5 years.
its time battery solutions were down to £2k, but still way too expensive. PW2 cost the same as our solar did! But it is more expensive if added later rather than installed as a bundle.
 
  • Like
Reactions: Tony1

·
Registered
Joined
·
57 Posts
Discussion Starter #18
We paid £8K 5.5 years ago for a dual array 5.6kW system, but it has paid for itself in 5 years.
its time battery solutions were down to £2k, but still way too expensive. PW2 cost the same as our solar did! But it is more expensive if added later rather than installed as a bundle.
Yes interesting really. Powerwall most expensive but best value by far per kWh from what I've seen
 

·
Registered
Joined
·
720 Posts
The energy saving trust did tests on peoples boilers, about 25 in total. This was on modern condensing boilers both combi and system. They proved that for the generation of hot water it was very difficult to achieve greater than 50% efficient for the combi and impossible for the system boiler system. This was measured as energy in v energy out.

The gas burning itself can be 90% but the overall boiler efficiency when warmed up and reached steady state is about 82%. In use of course in the non CH period one has the start and stop losses and pipe losses and tank losses for the system boiler. But even so the gas must still be cheaper than instant leccy, but not by much and entirely dependant on volumes of water and time of use. For most Agile customers however leccy might just have the edge.
 

·
Registered
Joined
·
1,129 Posts
If you have gas then a hot water diverter will actually cost you money. Each kWh you export will gain you 5.5p which you would lose if you diverted it. Gas only costs 2.5p per kWh. Diverters (just about) made sense for people getting deemed export payments but are not a good investment now that export must be metered.

My 3.42kWp array cost £4k in 2017 with a dual string inverter. They didn't use scaffolding though. I'd hope you could get 4kWp for around or under £4k now.
So when did compulsory export metering start ? I'm still on deemed export and have never been approached to fit an export meter.

And gas is not the only alternative to electricity for water heating ! My nearest gas main is approx a mile away from my house and zero chance of it serving here.
 
1 - 20 of 23 Posts
Top