New to Solar PV - any advice?

aj9648

Hi

I am looking at installing Solar on my roof.  Been quoted £7k for 11 SHARP All Black Solar Panel 400W panels.  This does not include storage.  With a battery its £10k and return on investment within 8 years. They have also said that they could integrate the panels into the roof by stripping the tiles and installing on the roof battens which looks pretty nice 

I will be honest with you that I have no idea about solar and what I should be looking for - so would you say this is a decent price?  

Edit - we used around 1000kwh per month and have 2 electric cars in the household

ABrass

£7k for 4.4kW is rubbish.

You haven't said how large the battery is? Without that it's impossible to say if it's good or bad, but I'd guess the second.

Return on investment of 8 years for £10k is it earning £1,250 a year. That is very ambitious. You'd have to assume you're using nearly all your power and that rates don't drop below 34p/kWh for the next eight years. Even with a huge battery you'd never use all your power during the summer months and even assuming Octopus Agile rates you don't earn as much for exports as your own use. Typically people assume self use of between 20-35% of their power without a battery and maybe up to 60% with a battery (numbers approximate).

In roof systems do look fancy, but I'm guessing it would be extra and it also makes the panels less effective so your return would be less.

Get more quotes.

ABrass

For your other questions: the single story roof might be worth looking at depending on shading and some fine details about the system.

If you are using optimisers or micro inverters then different rates of shading are fine, but if you don't then when any single panel gets some shade then the entire system stops producing.

The rule of thumb on Solar is that more is more.

aj9648

ABrass said:

£7k for 4.4kW is rubbish.

You haven't said how large the battery is? Without that it's impossible to say if it's good or bad, but I'd guess the second.

Return on investment of 8 years for £10k is it earning £1,250 a year. That is very ambitious. You'd have to assume you're using nearly all your power and that rates don't drop below 34p/kWh for the next eight years. Even with a huge battery you'd never use all your power during the summer months and even assuming Octopus Agile rates you don't earn as much for exports as your own use. Typically people assume self use of between 20-35% of their power without a battery and maybe up to 60% with a battery (numbers approximate).

In roof systems do look fancy, but I'm guessing it would be extra and it also makes the panels less effective so your return would be less.

Get more quotes.

5.8kWh Lithium Ion Storage which is £3k which has a Fox Hybrid ESS inverter with a Fox Energy Cube 5.8kWh Additional 2.9kwh battery is £1500

ABrass

That's not bad as things go for the battery. It's still pretty poor for the PV though.

Screwdriva

As others have said, you should be paying around £6.2K for 11X Sharp panels + 11 Optimizers and a SolarEdge inverter with 25 year warranty.

With 2 EVs, I would look carefully at your consumption/ charging patterns before determining whether to get a battery and more importantly, what kind of battery to invest in. A powerwall may make sense. 

ABrass

With 2 EVs and 1MWh a month use I'd be looking at a system twice the size. Assuming you ever have the option of charging tmin daylight hours