is solar worth it for me?

paradigital

For us, one of the main benefits we get from the battery is that we essentially time-shift all of our grid energy use to Octopus' cheap rate overnight (when the battery force charges from the grid if they aren't full).  Looking at my spreadsheet which compares our last full year of pre-solar installation with the last 12 months including solar, our payback is looking to be 5.91 years and that's WITHOUT a feed-in tarrif (we export very little anyway).

Over the last 12 months my average unit cost has been 8.13p/kWh (9.1 being the highest, 7.07 being the lowest pcm), even on the rainiest (or worse, snowiest) days our import usage outside of the "cheap rate" is miniscule.

Our energy use is higher though (medium-sized 4-bed detached, 4 occupants).  Our last full pre-solar year cost us £2418 in electricity (inc standing charge).  The last 12 months were £642.

QrizB

paradigital said:

Our energy use is higher though (medium-sized 4-bed detached, 4 occupants).  Our last full pre-solar year cost us £2418 in electricity (inc standing charge).  The last 12 months were £642.

A £2400 electricity bill means you're using almost 10,000 kWh a year. OP is only using 4,000 kWh, £1000 worth. You have much more scope to save money by time-shifting than they do, and bigger solar & battery installations are cheaper, pro-rata, than smaller ones are.

paradigital

QrizB said:

paradigital said:

Our energy use is higher though (medium-sized 4-bed detached, 4 occupants).  Our last full pre-solar year cost us £2418 in electricity (inc standing charge).  The last 12 months were £642.

A £2400 electricity bill means you're using almost 10,000 kWh a year. OP is only using 4,000 kWh, £1000 worth. You have much more scope to save money by time-shifting than they do, and bigger solar & battery installations are cheaper, pro-rata, than smaller ones are.

Absolutely, I'm not disputing that, however it's something most people seem to overlook when getting such a system installed.  Being able to not only provide your own generation, but also switch to a tarrif that allows you to reduce the cost of the grid import you do need helps the ROI.

It also means that you can potentially plan to move away from gas for say heating, or cooking.  Our energy use has increased since getting the solar (solar immersion, induction hob, planning to move to ASHP, etc).  I would estimate though that the majority of our delta between our consumption and the OPs comes from an EV and a PHEV, of which the OP has already put an EV on the table.

Screwdriva

kev1744 said:

ok...so quick measure of my roof and photo as requested... from what i can tell its about 4m by 4m. the panels the company use are dmegc 450 if that helps.

A couple follow up thoughts:

1) One of the installers I use will be able to fit 5 of the larger 590W panels (see pic above) on that roof (the chimney may block the 6th - only a survey will confirm this). That's a 3+ kW system size. 

2) DMEG are a very low end panel brand. I would suggest procuring quotes from installers who offer quality panel brands, such as Solarwatt/ Meyer Burger/ AEG/ Hyundai/ Sharp/ Eurener/ REA/ REC to name a few. Ideally, the bifacial variant of panel, so you can benefit from additional generation in UK conditions.

3) A quote for 5 X Sharp 590W bifacial panels + 5 SolarEdge optimizers + 1 SolarEdge 3kW inverter with 20 year warranty should cost around £4K installed, including bird netting. 

Hope this helps! 

kev1744

Screwdriva said:

kev1744 said:

ok...so quick measure of my roof and photo as requested... from what i can tell its about 4m by 4m. the panels the company use are dmegc 450 if that helps.

A couple follow up thoughts:

1) One of the installers I use will be able to fit 5 of the larger 590W panels (see pic above) on that roof (the chimney may block the 6th - only a survey will confirm this). That's a 3+ kW system size. 

2) DMEG are a very low end panel brand. I would suggest procuring quotes from installers who offer quality panel brands, such as Solarwatt/ Meyer Burger/ AEG/ Hyundai/ Sharp/ Eurener/ REA/ REC to name a few. Ideally, the bifacial variant of panel, so you can benefit from additional generation in UK conditions.

3) A quote for 5 X Sharp 590W bifacial panels + 5 SolarEdge optimizers + 1 SolarEdge 3kW inverter with 20 year warranty should cost around £4K installed, including bird netting. 

Hope this helps! 

it does help!.....i dont suppose you can recommend anyone in the leicestershire area can you?

Screwdriva

Happy to help! Not here to market on behalf of any installer but feel free to DM me and I’ll sort this for you! 

kev1744

ok...had 1 quote come in so far. anyone care to comment on below?

 5.4kW System - (although on the performance sheet it does say they expect it to only generate 4297kwh)

- 12 x Dmeg 450 watt Tier 1 All-Black Bifacial Panels (30 Performance Warranty) (8 panels on se facing roof 4 on nw)

- 1 x Solis 6kW Hybrid Inverter (10 Year Warranty)

- 1 x Pytes 5.12kWh Battery (10 Year Warranty- 6000 Cycles)

- Genius Slate Flashing System

- Bird Protection Guard
outdoor battery enclosure

includes all fitting scaffold etc.
£7695

still waiting for other quotes, so verdict anyone?

QrizB

kev1744 said:

ok...had 1 quote come in so far. anyone care to comment on below?

 5.4kW System - (although on the performance sheet it does say they expect it to only generate 4297kwh)

- 12 x Dmeg 450 watt Tier 1 All-Black Bifacial Panels (30 Performance Warranty) (8 panels on se facing roof 4 on nw)

- 1 x Solis 6kW Hybrid Inverter (10 Year Warranty)

- 1 x Pytes 5.12kWh Battery (10 Year Warranty- 6000 Cycles)

- Genius Slate Flashing System

- Bird Protection Guard
outdoor battery enclosure

includes all fitting scaffold etc.
£7695

still waiting for other quotes, so verdict anyone?

The price is OK. The kit is mostly budget brands.
I've got a Solis inverter (not a hybrid) and a neighbour has one of their hybrids; he's happy with it, it gives him some useful monitoring options through their app.

I've not heard of Pytes batteries but that's not a reason to reject them!

kev1744

ok had another couple of quotes.
anyone comment on which they think works out best?

 Size of system 4.5kW & 7kW of Battery Storage

Equipment;

  9 x 500w Eurener Nexa Topcon N-Type Bi-Facial Panels 30-year warranty

  9 x Solar Edge optimizers fitted to each panel. 25-year warranty.

  1 x Solar Edge SE5000 inverter 20-year warranty

  1 x Growatt SPA3000 AC/DC Controller 10-year warranty

  1 x Light Renewables 7kW battery 20-year warranty

  1 x Bird Protection

  1 x All cable run’s isolators and fitting’s

  1 x Micro generation meter

  1 x System Wi Fi monitor

Fully fitted price of £8,195.00 

Size of system 4.5kW & 7kW battery storage

Equipment;

  9 x 500w Eurener Nexa Topcon N-Type Bi-Facial Panels 30-year warranty

  1 x Growatt SPH5000 Hybrid battery ready inverter 10-year warranty

  1 x Light Renewables 7kW battery 20-year warranty

  1 x Bird Protection

  1 x All cable run’s isolators and fitting’s

  1 x Micro generation meter

  1 x System Wi Fi monitor

Fully fitted price of £7,595.00

An Evergreen Power 5.4kW System

-- 12 x Dmeg 450 watt Tier 1 All-Black Bifacial Panels (30 Performance Warranty)-( 4 of these panels would be on a nw roof so possibly ltd energy generation?)

1 x Solis 6kW Hybrid Inverter (10 Year Warranty)-

1 x Pytes 5.12kWh Battery (10 Year Warranty- 6000 Cycles)-

Bird Protection Guard-

 Total £7,445 

Screwdriva

Last I heard, the installer was able to fit 9 X 500W Black bifacial panels on OP's roof - an incredible result to answer the original question with a resounding 4.5kW+ packing yes! (I hope OP will share images soon)