Quote check please - Solar & Battery
Hello!
We're new to solar and looking for some thoughts on three quotes we've received - they're all very similar total amounts, but the cost breakdown seems to focus on different things, so we'd love any thoughts on which you think looks best (or any red flags you see!). We had a 12 kWh ASHP installed last October, and live in a fairly exposed detached house in Scotland, so we get through a lot of kWh, especially in winter!
Region - East Scotland
Yearly kWh - around 12,000 kWh
Tariff - Currently on Octopus Cosy, but open to changing if another tariff works better with a solar/battery set up.
All three quotes have suggested installing panels on both sides of the house (faces east-west), and on our external double garage (which faces north-south) - so this presumably means 3 lots of scaffolding.
Quote 1:
12.15 kW PV System
- 27x Trina Vertex S+ 450W Dual Glass Full Black N-Type Mono (split across 3 arrays of 8 × 450W, 5 × 450W & 14 × 450W panels)
- Inverter: 1 × Sigenergy Sigenstor 10kW 1ph Hybrid
- Batteries: 3x Sigenergy 8.76kWh Battery (Giving 26.3 kWh usable battery storage)
- Sigenergy Back up gateway
Predicted annual generation: 9,887 kWh per year
Cost:
£16,519.72 equipment
£4400 installation (including scaffolding)
Total - £20,919.72
Quote 2: (Worth mentioning - the only installer who has done an in person survey/quotation and it seems the most conservative in terms of output, so maybe the most realistic?)
12.60 kW PV System
- 28x Trina Vertex S+ 450W Dual Glass Full Black N-Type Mono (Traceable) (split across 3 arrays of 6 × 450W, 6 × 450W & 16 ×
450W panels)
- Inverter: Fox ESS KH 9kW 1ph Hybrid Inverter
- Batteries: Fox ESS CQ7 7.02kWh Battery - 1 x master and 3 x slave batteries, total 28.1 kWh battery storage
- Fox ESS EPS 1ph Backup Box
Predicted annual generation: 7,145 kWh per year
Cost:
£11,712.94 equipment
£9300 installation (including scaffolding)
Total - £21,012.94
Quote 3:
10.78 kWp total array
- 22 x Aiko S3 490W All Black solar panels (Array split across 3 roofs: 16 panels to the main tiled roofs and 6 panels to the metal roof)
- Inverter: Sigenergy EC 10kW single phase Energy Controller
- Batteries: 3x Sigenergy SigenStor - 27.12 kWh battery storage
- Sigenergy Backup Gateway
- Bird proofing to the tiled roof array
- Optional extra: upgrade the inverter to a 12kw for an additional £110.
Predicted annual generation: 8,300 kWh per year
Cost:
Total, supplied and installed: £20,720
It is my understanding that we would additionally have to pay for a G99 application on top of these quotes - one company mentioned it would be between £250-£600.
Any insight into the chosen gear, prices or any concerns with the above would be very much appreciated! Thanks in advance