Business solar savings calculator
Enter your electricity spend to estimate the system size, annual saving, payback and year-one tax relief for your business. Indicative only, not a quote.
Indicative estimate
- Recommended system
- 90 kWp
- Annual saving
- £23,940
- Simple payback
- 3.2 years
- Year-one tax relief (AIA)
- £19,125
- CO₂ saved
- 17.7 t/yr
- 25-year saving
- £598,500
Assumptions: ~950 kWh per kWp per year (UK average), indicative installed cost ~£850 per kWp, exported units at an 8p Smart Export Guarantee rate, Annual Investment Allowance relief at 25% corporation tax. These are illustrative defaults; your figures depend on roof, shading, load profile, tariff and tax position. This tool does not store any data you enter.
Calculator FAQs
How accurate is this calculator?
It gives an indicative estimate from standard UK assumptions: roughly 950 kWh generated per kWp per year, an install cost near £850 per kWp, and an 8p Smart Export Guarantee rate for exported units. Your real figures depend on your roof, orientation, shading, load profile and tariff. A firm figure needs your half-hourly meter data, which an installer can model.
What is self-consumption and why does it matter?
Self-consumption is the share of solar you use on site rather than export. On-site use saves the full electricity price you would otherwise pay, around 26 to 32p, while exported units earn far less under a Smart Export Guarantee tariff (British Gas, for example, pays business supply customers up to 8p a unit and other businesses 3p), so a self-consumed unit is worth three or more times an exported one. A higher daytime load means a shorter payback, and the slider lets you set your daytime usage share.
Does the estimate include tax relief?
Yes. Solar PV is special-rate plant and usually qualifies for the Annual Investment Allowance, so we show indicative year-one relief at the 25% corporation tax rate. Solar does not qualify for 100% full expensing, which is main-rate only. Your actual eligibility depends on your tax position and profits, so confirm with your accountant.
Is this a quote?
No. It is an indicative estimate to help you scope the funding decision. A firm proposal needs your meter data, a roof assessment and a grid check from an MCS-certified installer.