Is this a sensible quote for a flat roof?

[MrTWales]

It's a tough time to get quotes it seems, but I finally have one. I must admit, I did think that there was no VAT on equipment if it was part of an install but I guess not.

 

I'm a bit dubious about how this connects to the roof, esp baring in mind that this was just sent after I sent a couple of pictures (ie they were never on site). The one guy to visit (quotation pending) said that they would use a ballast method, but this seems like it's something different. 

 

Anyway, any comments would be appreciated!

 

 

[Radian]

£1.40 per Watt Peak. Seems like the sort of figures I saw in the 1st quarter of this year. Probably reasonable given the problems getting quotes these days. Can't remember the last time it was £1/Watt.

[MrTWales]

Thanks - I've asked about battery options but I'm still confused about the VAT. Just Googling it now it seems like the change in March covered materials and not just the actual install costs.

[nod]

Probably take a couple of decades to get your initial outlay back

[LA3222]

43 minutes ago, nod said:

Probably take a couple of decades to get your initial outlay back

I only gave a cursory glance to the quote, but a couple of decades to recoup initial outlay - really.

 

Nah. Will recoup it a lot faster than that, especially when prices go up again in October.

[MrTWales]

59 minutes ago, Radian said:

£1.40 per Watt Peak. Seems like the sort of figures I saw in the 1st quarter of this year. Probably reasonable given the problems getting quotes these days. Can't remember the last time it was £1/Watt.

 

1 minute ago, LA3222 said:

I only gave a cursory glance to the quote, but a couple of decades to recoup initial outlay - really.

 

Nah. Will recoup it a lot faster than that, especially when prices go up again in October.

 

For what it's worth, the quote is part of a pack with all sorts of data and charts (no idea how standard that is). It comes up with a payback period of 9 years. Maybe that could be optimistic, but I do work from home so could use a fair chunk of enegy in the day. Plus my next car will be electric and that will be sat in the driveway most days so that could add value. In any case, I want to maximise fun and not money and solar panels would be fun for me!

 

 

[nod]

37 minutes ago, LA3222 said:

I only gave a cursory glance to the quote, but a couple of decades to recoup initial outlay - really.

 

Nah. Will recoup it a lot faster than that, especially when prices go up again in October.

On our last build Finished three years ago The SAP predicted saving for a full PV array was £200-300 per year 

Outlay £9500 

This time we are being told that we could save up to £500 -700 per annum 

I asked our Architect if it was financially viable He repeated what a wise man on here said 

Buy cheap and self install 

 

[SuperJohnG]

7 minutes ago, nod said:

Buy cheap and self install 

This is definitely the way and if anyone reads this and you're doubting solar PV and not got slates or tiles on yet...get it done...not ever will it be as cheap to do it as at that point in time. 

 

I'm currently preparing but not committed to ripping off a bunch of perfectly graded slates. 

 

As a benchmark on that quote I was quoted about £3k about 2 or 3 months ago for a 4kWp system.  I'll look out the quote. 

[Iceverge]

1 hour ago, SuperJohnG said:

currently preparing but not committed to ripping off a bunch of perfectly graded slates. 

 

You could consider a pretty henhouse/bicycle chalet like @ProDave

[Dillsue]

9 hours ago, Iceverge said:

 

You could consider a pretty henhouse/bicycle chalet like @ProDave

Thats a great option if theres no spare higher roof space but check the track of the sun and see where abouts stays in full sun for longest. Weve just put in a 3kw ground array with a further 2kw to go on the ground but realised that where the 2kw was planned to go gets shaded way before a spare bit of the main house roof does. The 2kw is now going up on the roof where it gets an extra hour of direct sun. The orientation isnt ideal but when comparing hourly figures from PVGIS at the time of day we want the extra production, the seemingly poor orientation doesnt make much difference.

[SteamyTea]

11 hours ago, LA3222 said:

Nah. Will recoup it a lot faster than that, especially when prices go up again in October.

What if the price goes down.  Wholesale gas prices are down, as are volumes.

https://www.catalyst-commercial.co.uk/wholesale-gas-prices/

Edited May 23, 2022 by SteamyTea

[Radian]

11 minutes ago, SteamyTea said:

What if the price goes down.  Wholesale gas prices are down, as are volumes.

 

Doesn't this just reflect the fact that we are one of the few countries to have LNG terminals that can handle deliveries? While the rest of Europe builds its capacity we're doing the importing and currently using CCGT and the DC interconnect to export electricity as much as we can while the demand is there?

[SteamyTea]

1 minute ago, Radian said:

Doesn't this just reflect the fact that we are one of the few countries to have LNG terminals that can handle deliveries?

Partly.

We also have a lot of spare gas powered electrical generation, and we can easily export around 4 GW of electrical power to Europe.

 

As with any 'crisis', making the right short term decisions are not always the best long term.  But the consequences of wrong short term decision is currently no power.

[Radian]

12 hours ago, MrTWales said:

 

 

For what it's worth, the quote is part of a pack with all sorts of data and charts (no idea how standard that is). It comes up with a payback period of 9 years. Maybe that could be optimistic, but I do work from home so could use a fair chunk of enegy in the day. Plus my next car will be electric and that will be sat in the driveway most days so that could add value. In any case, I want to maximise fun and not money and solar panels would be fun for me!

 

 

Yes it can be fun to see useful energy being generated at your own property. But £6K buys 20 Megawatt hours of electricity at todays prices. I could munch through that in 5 years but it might keep most people supplied for 10. If prices go up to 50p/kWh and stay there for 5years of so it starts to look more viable. But that's a big if.

[MrTWales]

55 minutes ago, Radian said:

Yes it can be fun to see useful energy being generated at your own property. But £6K buys 20 Megawatt hours of electricity at todays prices. I could munch through that in 5 years but it might keep most people supplied for 10. If prices go up to 50p/kWh and stay there for 5years of so it starts to look more viable. But that's a big if.

 

At the end of the day, I can afford it and want to do the right thing + geeky tendanices would provide some fun + I hate waste and seem to spend half may day turning lights off after people etc (they are LED so hardly drawing any power, but still). I just want to get a decent quote with low risk  of a bad install - perhaps this quote is reasonable but it worries me a bit that they didn't even visit the house.

 

I think the equation must be something like 50% of power used if self generated over a year (or a little less if you can reduce gas usage a bit). This seems very optimistic to me in general, but for me perhaps it is may be viable. I do work from home and the washing machine/dishwasher can always run during the day (anyway actually as they are smart or at least have a timer), plus lots of cooking. This would probably be the only time we use the two electric hob rings that we have (we use the gas ones) as I guess that would be better if there was enough excess. Plus there are tiny savings from using the emmersion heater sometimes etc, and some way down the line an electric car.

 

Anything that needs a payback period of 9/10 years must make a lot of assumptions but interest rates are very low (so you can't invest and get a decent return without taking a risk) and the panels themselves should last for ages. My parents got panels installed around 15/20 years ago (they got a grant and get paid by the grid even now) and there hasn't been a single problem with them. I guess inverters and batteries may not last so long, no idea.

 

 

 

[Radian]

50% self used sounds pessimistic but it's probably too optimistic. It's difficult to use every drop of power and not a Watt more than you need to - even with a solar diverter to immersion. The coincidence of lower heating use and higher Solar supply in the summer is a PITA. Batteries are the go-to solution but push the ROI out twice as far. I personally favour a smaller PV array of, say, no more than 3kWp and both divert to immersion as priority and to Air Conditioning as a second way to burn off excess. Both are controllable and perform useful work.

[MrTWales]

Thanks, interesting. 

 

The one guy that came around (quote pending) said that any diversion to an immersion heater wouldn't be covered as they have had so many issues with them. But they would install a wifi switch, for example, if I got one but it wouldn't be under the warranty. To be honest, I'm happy with that as I won't have any excess for much of the year (so gas is better) and the hot water tank keeps water hot for days if it's not used and I only use the gas for three 30 mins slots a week now with the occasional boost. I've not looked into it but I'd hope that you could do clever things with a wifi switch also (eg use certain triggers if it works with IFTTT etc).

 

I'm not sure about a battery yet so I'll see what the extra cost is. The guy who came around said that he has a tarrif where electric is cheaper at night so the battery gets charged then. 

[Dillsue]

38 minutes ago, MrTWales said:

 I'm happy with that as I won't have any excess for much of the year

Unless youve got an automated excess generation consumption system(batteries/pv diverter) youll likely always have excess, unless youve got a relatively small system for the size of your house base load. Most of the significant household loads are intermittent when they are running so even if you stagger appliance use there'll be lots of periods when an appliance is running but only using a small amount of generation with the rest going to grid. A washing machine for instance only heats and draws a big load for a small proportion of the wash cycle so when its not heating any excess not used for base load in the house will go to grid.

[MrTWales]

Surely I won't have much excess in the winter though? I've been assuming that there will be weeks when the panels generate hardly anything. The gas cost is actually interesting to me as I looked at gas usage at the same time I looked at electric (turns out I use ~ 10Kwh per day on average for electric). I knew that heating was a huge part of the gas cost, but even allowing for no heating for half the year it's still 80% of the total or around there. Based on the lowest months it really seems like heating the water and using the gas hobs doesn't actually cost all that much.

 

I'm probably tending towards getting a battery so I guess that changes things too as I won't waste anything then in the winter so would be better off using gas for the water. 

[Dillsue]

41 minutes ago, MrTWales said:

Surely I won't have much excess in the winter though?

Thats sometimes true, but winter alone isnt "much if the year"

 

I tested 3kw of panels in feb this year propped up on the ground facing south and they were generating 2kw on sunny days

[MrTWales]

Ah interesting. Looks like I wasn't quite getting how much you can get in the winter months. I was assuming that there would be virtually nothing for three months, not that much for another three, and a decent amount for the rest. 

 

My panels will be flat-ish so it's not optimal, but then again I'd get sun for longer and there isn't really any shade.

[Wil]

I only have data for the last winter, but my fairly unshaded 5kWp array on a 3.68kWp inverter generated 85kWh in Dec for an average of 2.5kWh per day. November was 185kWh and Jan was 205kWh. So it was only really deepest darkest Dec when I wasn’t getting much output.

[MrTWales]

Wow, that really is way more than I thought. Based on that I'd think that it is viable for people who work at home and change a few habits to get >50% from the panels? 

[94JDH]

On 22/05/2022 at 19:18, MrTWales said:

It's a tough time to get quotes it seems, but I finally have one. I must admit, I did think that there was no VAT on equipment if it was part of an install but I guess not.

 

I'm a bit dubious about how this connects to the roof, esp baring in mind that this was just sent after I sent a couple of pictures (ie they were never on site). The one guy to visit (quotation pending) said that they would use a ballast method, but this seems like it's something different. 

 

Anyway, any comments would be appreciated!

 

 

The VAT should be on the total work, so you should still be saving that £823.88 It's still a little high in my opinion but market is swamped with enquiries - I would recommend getting a few more for comparison.

 

EDIT: for your other question, the renusol console, as per your quote, is ballast weighted - they are usually filled with bags of stone or similar)

Edited May 24, 2022 by 94JDH

[MrTWales]

1 hour ago, 94JDH said:

The VAT should be on the total work, so you should still be saving that £823.88 It's still a little high in my opinion but market is swamped with enquiries - I would recommend getting a few more for comparison.

 

EDIT: for your other question, the renusol console, as per your quote, is ballast weighted - they are usually filled with bags of stone or similar)

 

Thanks, that is useful. Just to be clear, you are saying that they have got the quote wrong by including the VAT? That doesn't fill me with much confidence if true.

 

Ah I see, that makes sense. I did Google it and it seemed like it may clip on somehow but without more info I'm not sure how they could reckon on penatrating the roof or slipping on the sides. It really does seem like what they use for ballast is always ugly looking!

 

Trust me, I'm trying to get more quotes! Most of the time I've not even got a reply, but one guy did some around and another is coming on Monday so I may end up with three which would be OK. One firm, who are 45 mins away, said that they are so busy in the local area that they don't cover wider afield at the moment. Baring in mind that this is on a flat roof (so no scaffolding) and I assume it's one day's work (?), that shows how much work this sector is getting right now.