Solar Panel Price Check and Advice

pramsay13

We've had a couple of people out to give us quotes for solar panels and they are quite different so looking to check prices and asking for any advice from people who have had it installed.

We are in a 4 bedroom end terrace house, with estimated usage around 10,000kWh annually.

First one was a salesman for a large company with a fancy computer programme that showed how panels would look on the roof, and with graphics showing how much we would save over the lifetime of the panels etc.
Second one was an installer that works with just him and his brother. 

1. 14 x JA Solar 365W panels - 5.11kW system - Solis Inverter - Puredrive Battery - £10,785

2. 12 x Trina Solar panels - 8 x 400W, 5 x 500W - 5.7kW system - Solis Inverter - no battery - £4,800

ABrass

Batteries don't normally make sense financially at the moment. They're still too expensive, although you might break even eventually.

2 quotes aren't enough. However the second quote is pretty good, it's less than £1/kWp.

silverwhistle

Normally when people come on here with their quotes from dodgy double glazing type salesmen and installers we give a rapid collective intake of breath. In your case quote number 2 looks pretty good. If you've a hot water tank ask them to throw in an iboost diverter for spare energy* and it would be a good deal if it's a decent installation.

* You may want to export it instead depending on circumstances.

arty688

I would also ask no 2 for some previous customers .

Is it 2 roofs ? 
I do like the way No2 has used 2 types of panels most places don't seem to consider that I would assume the inverter has 2 strings but worth a check.

Also what size is the inverter?

Meatballs

Second quote is pretty decent on the face of it. I would ask about bird proofing and double check the inverter is dual MPPT to handle the mixture of panels on two strings?

Petriix

ABrass said:

Batteries don't normally make sense financially at the moment. They're still too expensive, although you might break even eventually.

2 quotes aren't enough. However the second quote is pretty good, it's less than £1/kWp.

Batteries are very much starting to add up with prices as they are. Best case figures for a 7.2kWh pylontech system are showing a < 6 year ROI for me now.

Hexane

pramsay13 said:

We are in a 4 bedroom end terrace house, with estimated usage around 10,000kWh annually.

That's quite high usage, makes a solar install very worthwhile, especially if electricity prices go insane next year as currently predicted.

pramsay13 said:

First one was a salesman for a large company with a fancy computer programme that showed how panels would look on the roof, and with graphics showing how much we would save over the lifetime of the panels etc.
Second one was an installer that works with just him and his brother. 

I ended up buying from an installer whose company consisted of him as the qualified electrician and proprietor, and two other guys to help with the actual panel installation and scaffolding etc. He also had the fancy computer program, and much more professional surveying than the large company "surveyor"/salesmen.

The small company got my business because the large companies wanted to fit me into their "one size fits all" solution instead of trying to provide what I'd asked for.

Based on what I've seen on this board over the last year or so, the large companies are now moving to offering a battery with all installations as their "one size fits all", maybe just because it pushes the total cost towards or over £10,000 so makes it worth their while to keep employing full time salesmen.

pramsay13 said:

graphics showing how much we would save over the lifetime of the panels 

These are often worth ignoring. For example many installers used to base these estimates on a combination of, firstly your being able to use 50% of the energy generated when that generally wasn't the case, and secondly an unrealistic estimate of future year-on-year price inflation of electricity. My installer used a more realistic estimate of being able to use 33% of the energy generated.

pramsay13 said:

2. 12 x Trina Solar panels - 8 x 400W, 5 x 500W - 5.7kW system - Solis Inverter - no battery - £4,800

This looks very good, given how prices seem to have risen a little recently.

Some things to ask about:

1. What is the maximum power output of the inverter? This quote is 5.7kWp. My installation is 7.25kWp with a 6kW inverter. Some installers will sell you a 5.7kWp system with a 3.6kW inverter. If your roofs are west and east facing, you might not mind that you will never generate more than 3.6kW at any one moment from your 5.7kWp system, but you need to know.

2. If the inverter is more than 3.6kW (or "4kW"), does the installation price include seeking DNO approval?

3. Are there any shading issues?  (e.g. from a chimney or similar) Even slight shading hitting one panel, will massively impact all other panels on that string.

(I don't have a battery and don't know enough to comment on whether the quote with a battery is good value or whether things have changed sufficiently recently that battery systems have become good investments or not)

Heedtheadvice

Cannot really comment on the two man band (the quote cost seems good but devil in the detail as pointed out above).

However it is very worth considering irrespective of supplier/installer hiw you feel about their service record with other customers and the likelyhood of them still being in business in a few years time. That is difficult to judge but if solar panels are their only source of income then that could increase risk. Track record could be valuable too. Problably still the case of cowboys in the business especially those who push batteries and claim huge savings.

Assumption your 10k kWhs is electricity use for all power, otherwise it is exceedingly high.

pramsay13

Thanks for your comments everyone. I'll work through them and ask questions.

We do have 2 roofs. I've attached the picture from the fancy sales pitch showing a suggested layout. One roof faces south east and one faces south west so both will get the sun most of the day. There are no shading issues.

10000 kWh is probably fairly accurate. We have a hot tub which means it is higher than it should be and that's what prompted us to look at solar panels. 

pramsay13

Here is the photo of the proposed layout from the salesman. South is to the bottom of the photo. 

arty688

Assumption your 10k kWhs is electricity use for all power, otherwise it is exceedingly high.

My electricity use is about 22000 kwh so it could be worse... No gas though