canalsiderenovation Posted August 26, 2020 Share Posted August 26, 2020 (edited) So, now is the time we need to decide whether to go for in roof solar on one side of the roof (old Google image for info). Note a lot of these trees have gone and there is no shading. My other half doesn't think it is cost effective and I'm trying to drive the cost down. We approached two companies, both MCS accredited who came back with some prices which seemed expensive. We aim to avoid getting prior DNO permission and as I understand it the Peak Wattage of the PV array should fall within the inverter’s power tolerance and it is the inverter’s maximum output capacity that needs to be 16Amp (per phase) or less in order to not require permission from the DNO fall within G98 regulations. The quote I've had from one supplier recommended by a few people here is attached and they said the spec they have quoted for means it won't need DNO advance approval. There is then the additional cost of our electrician and roofer fitting it. We will have our ASHP and the solar is for our use and to divert any excess to the immersion tank (300 litre minimum just waiting for quote). Would someone mind taking a look at this quote (14 panel system) and seeing if there is anything missing and if there is any way of reducing cost and things that should/should not be included. At these figures my other half is reluctant and doesn't think it is worth pursuing? I'm hoping @ProDave will be along too and other people that know far more than me @PeterW? Thanks Edited August 26, 2020 by canalsiderenovation Link to comment Share on other sites More sharing options...
tanneja Posted August 26, 2020 Share Posted August 26, 2020 Just to confirm, is that breakdown looking like £35k? Link to comment Share on other sites More sharing options...
canalsiderenovation Posted August 26, 2020 Author Share Posted August 26, 2020 2 minutes ago, tanneja said: Just to confirm, is that breakdown looking like £35k? Inc VAT just a few quid over £4k. Link to comment Share on other sites More sharing options...
tanneja Posted August 26, 2020 Share Posted August 26, 2020 (edited) Ah the quantity is included in the cost per item, no idea how i missed that, thanks Edited August 26, 2020 by tanneja Link to comment Share on other sites More sharing options...
LA3222 Posted August 26, 2020 Share Posted August 26, 2020 @canalsiderenovation that quote structure looks similar to how midsummer wholesale structure their stuff - check out their site and you'll get a flavour for pricing. They have a link to an app on their site which spits out the material quantities for you based on your roof size. Very easy to use. Easy to get a 'trade' login with them too for slightly better pricing. 1 Link to comment Share on other sites More sharing options...
ProDave Posted August 26, 2020 Share Posted August 26, 2020 So that's about £4K total in parts including the in roof mounting kit. How much will you save by not having to tile the majority of that face of the roof? Installation wise your electrician and the roofer should be able to fit that lot without difficulty. 1 Link to comment Share on other sites More sharing options...
Ferdinand Posted August 26, 2020 Share Posted August 26, 2020 There's probably a detailed post of Jeremy's blog somewhere about his in roof solar. Home page: http://www.mayfly.eu/ F 1 Link to comment Share on other sites More sharing options...
canalsiderenovation Posted August 26, 2020 Author Share Posted August 26, 2020 2 hours ago, ProDave said: So that's about £4K total in parts including the in roof mounting kit. How much will you save by not having to tile the majority of that face of the roof? Installation wise your electrician and the roofer should be able to fit that lot without difficulty. Rough guesstimate around £3-£400 builder said (our roof tiles are Marley something or other so not posh slate or anything). Link to comment Share on other sites More sharing options...
JamesP Posted August 27, 2020 Share Posted August 27, 2020 Fitting PV from a financial point of view would probably take at least 10 - 15 years to recoup the original outlay without any FIT. Link to comment Share on other sites More sharing options...
canalsiderenovation Posted August 27, 2020 Author Share Posted August 27, 2020 43 minutes ago, JamesP said: Fitting PV from a financial point of view would probably take at least 10 - 15 years to recoup the original outlay without any FIT. This is the argument I'm having with my other half who is saying it doesn't make sense financially. Link to comment Share on other sites More sharing options...
LA3222 Posted August 27, 2020 Share Posted August 27, 2020 (edited) 1 hour ago, JamesP said: Fitting PV from a financial point of view would probably take at least 10 - 15 years to recoup the original outlay without any FIT. How can you know that? You are making some very broad brush assumptions to arrive at such a conclusion. Do you know what will happen to energy prices over that 15yr period as that will have a material impact on the repayment timeline? Or do you assume today's prices will apply in 15yrs time? Do you know how much they will generate or is this an assumption again? Do you know how much they will use out of what is generated? I'm not having a go at you, I'm taking aim at how this is not a binary decision. It is too complex to just divide the cost by the assumed energy produced and then compare that to todays energy prices to arrive at the answer. My own view is that the climate is going tits up, energy prices will most certainly rise - we are already scraping the barrel for being able to produce enough of it, power plants are getting older, new ones will cost a load of cash which will no doubt get passed on to the consumer. If the summer temperatures get more extreme will air con in the home become the norm for this country like others overseas? If so, the PV will pay the bill for that use. There are lots of tangential arguments as to why PV is worth doing but they tend to get overlooked/dominated by the financial argument. Yes its a high outlay, but if you're in the house for the long haul then at some point it will be worth that initial bank balance hit. Edited August 27, 2020 by LA3222 3 Link to comment Share on other sites More sharing options...
ProDave Posted August 27, 2020 Share Posted August 27, 2020 My own summary, if it's going to coast £4K for the kit, less the saving on roof tiles, plus the labour to fit it, I guess that's about £4K total then. My own system I self use about £250 worth of electricity each year. My own system is hampered by shading once the trees get into leaf I lose a lot in the mornings (more tree thinning needed to address that) Lets say you have no shading and manage to self use £300 worth of electricity each year. That will therefore take you 13 years to pay back the cost. Less time if energy prices increase. Only you can make that decision. For me personally that would be too long. I scoured the earth (well the internet anyway) and got the very very cheapest I could and ground mounted it all myself and will have a payback time of 6 years. I really don't think it is worth paying for an MCS install just so you can claim the ~5p per unit export payment. I have exported so little in the last 3 years that had i been eligible I would have been paid just £11 so far. If I had paid extra to have an MCS install I would never ever recoup that extra cost. That export payment thing is a political gesture. Link to comment Share on other sites More sharing options...
JamesP Posted August 27, 2020 Share Posted August 27, 2020 1 hour ago, canalsiderenovation said: This is the argument I'm having with my other half who is saying it doesn't make sense financially. For the long term greater good fit PV. Link to comment Share on other sites More sharing options...
Conor Posted August 27, 2020 Share Posted August 27, 2020 fitting PV is more about reducing demand on the network and reducing the carbon footprint of your lifestyle.... e.g. timing your heat pump, car charging, washing machine etc to make use of PV electric to reduce usage from the carbon intense network. it depends if that is important to you or not. As above, payback is usually in the 10-15 year bracket. I'm going for a 6pkW system split over three roofs with a 4kw inverter. It's coming in a shade under £5k. Excludes wiring and commissioning. 1 Link to comment Share on other sites More sharing options...
SteamyTea Posted August 27, 2020 Share Posted August 27, 2020 21 minutes ago, Conor said: fitting PV is more about reducing demand on the network and reducing the carbon footprint of your lifestyle To a certain extent it is. And how many people think that spending 5K extra on a kitchen will save them that on not eating out. What is the payback on a £800 bath compared to a £200 bath? Or a £1000 kitchen tap that boils water compared to a £50 one and a tenner for a kettle. 7 Link to comment Share on other sites More sharing options...
dnb Posted August 27, 2020 Share Posted August 27, 2020 Why do you not want to deal with the DNO? Mine were quite approachable and I now have an offer for 6kW single phase generation. I am not going down the MCS route because it looks like a gravy train with no benefit to me because I ought to be able to self use most of the apprx. 7000kWh the system is estimated to produce in a year (all electric house with full AC and planning for an electric vehicle). My payback around 5 years in theory. I would suggest GSE in roof parts might be a little cheaper than the Easy roof. You could also save a little on a different inverter. But either way it won't be a huge amount. Why not download a PV generation predictor and model your house and system with it? Then you'll have some numbers to work with so you'll be better able to estimate usage and form plans. Link to comment Share on other sites More sharing options...
canalsiderenovation Posted August 27, 2020 Author Share Posted August 27, 2020 47 minutes ago, dnb said: Why do you not want to deal with the DNO? Mine were quite approachable and I now have an offer for 6kW single phase generation. Prior permission needed and timescales. 48 minutes ago, dnb said: Why not download a PV generation predictor and model your house and system with it? Then you'll have some numbers to work with so you'll be better able to estimate usage and form plans. Can you recommend a PV generation predictor I can use? Link to comment Share on other sites More sharing options...
SteamyTea Posted August 27, 2020 Share Posted August 27, 2020 https://re.jrc.ec.europa.eu/pvg_tools/en/#PVP Link to comment Share on other sites More sharing options...
ProDave Posted August 27, 2020 Share Posted August 27, 2020 1 hour ago, dnb said: Why do you not want to deal with the DNO? Mine were quite approachable and I now have an offer for 6kW single phase generation. I know our local network is near capacity. We were only offered a 12KVA supply for the new house. I knew if I wanted more than 3.68kW of PV there would be an upgrade charge. This was confirmed when I registered my 3.68kW system, they mistakenly took the "4000" in the inverters model number to mean it was a 4KW inverter and instructed me to disconnect it and they would prepare a quote for the network upgrade. That was resolved when I supplied them the manufacturers specifications showing the inverter output was limited to 3.68KW So it was not so much of would there be a charge for more than 3.68KW, it was just a question of how much of a charge. I suspect the transformer at the top of our road would need upgrading and I doubt it would be a cheap upgrade. I did not want to be the one paying to upgrade a struggling network. Link to comment Share on other sites More sharing options...
dnb Posted August 28, 2020 Share Posted August 28, 2020 20 hours ago, canalsiderenovation said: Can you recommend a PV generation predictor I can use? I downloaded a trial version of "PV Sol". Not the easiest to use, but it produces nice pictures and seems to match reality - I modelled a friend's existing PV scheme and got good agreement with historic results. 1 Link to comment Share on other sites More sharing options...
canalsiderenovation Posted September 3, 2020 Author Share Posted September 3, 2020 So some reduction on pricing and we some shoppinf around. Note we had to change from 14 panels to 12 as the roof was a bit smaller than initially predicted. They have changed the Fronius inverter 3.6 as the Primo will not work with 2 rows of 6 using these panels they have quoted for, instead a Growatt which is compatible. Does anyone have any knowledge of these products/comments on this pricing for the supply of GSE in roof panels etc and diverter for the water to immersion for ASHP? Link to comment Share on other sites More sharing options...
tonyshouse Posted September 3, 2020 Share Posted September 3, 2020 Try solar streets 4k for 4kWp 1 Link to comment Share on other sites More sharing options...
ProDave Posted September 3, 2020 Share Posted September 3, 2020 That revised quote is looking a whole lot better. 1 Link to comment Share on other sites More sharing options...
canalsiderenovation Posted September 3, 2020 Author Share Posted September 3, 2020 Just now, ProDave said: That revised quote is looking a whole lot better. I think so, just need to check what our builder/spark is going to charge for fitting. Link to comment Share on other sites More sharing options...
gc100 Posted September 4, 2020 Share Posted September 4, 2020 On 27/08/2020 at 09:48, canalsiderenovation said: This is the argument I'm having with my other half who is saying it doesn't make sense financially. My electrician can supply a 8k. PV system for about £2k, plus a couple of days work (£360). This is trade prices with no markup Link to comment Share on other sites More sharing options...
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