UK Farm Solar Case Study: 3-Year Payback, ~£500k of 30-Year Savings

The problem: paying the energy company instead of owning the asset

The farm's annual electricity demand sat at 37,000 kWh. Every kilowatt-hour was rented from the grid at retail rates with no residual value at the end of the year. Kieran from KMM framed the choice on site: "instead of giving it to the energy company, obviously you invested in your own technology and your own power station."

Energy inflation made that trade-off worse over time. Using Office for National Statistics data from 2000 to 2021 — deliberately excluding the volatile last three years — bills rose roughly 7% a year on average. Over Kieran's own working tenure from 2017 onwards, the lived figure has been an average of 14.7% a year. Either trajectory turns a static fuel bill into a growing liability for a farm with decades of operation ahead of it.

What KMM did: oversize for resilience, model the economics first

KMM specified an installation generating 50,000 kWh a year against 37,000 kWh of usage. The 13,000 kWh of headroom is deliberate — the owners wanted to future-proof the farm for electrification of vehicles, heat and equipment, and to bank exported units as a financial buffer against winter consumption.

With the system commissioned, KMM is now working with the client to secure a competitive export tariff. As Kieran put it on site, the excess generation acts as "an extra battery to help offset their winter usage" — exported summer units monetised at a rate that, combined with self-consumption savings, drives the payback.

The numbers: 3-year 3-month payback, ~£500k over 30 years

The model KMM built for the client lands at:

• Payback: 3 years 3 months
• Year-one return: just over 30%
• 30-year savings (base case): just shy of half a million pounds
• 30-year savings (if inflation tracks the 14.7% trajectory): over £1 million

Kieran's framing of the first few years is honest: "initially not much changes for the first few years. Instead, it's a sort of robbing Peter to pay Paul exercise." The cashflow that used to leave the farm as an energy bill now services the system instead — but at the end of the payback window the farm owns a producing asset for the remaining ~27 years of useful life.

Why the headroom matters: the next energy crisis

The investment thesis Kieran walked through on site is about asymmetric risk. As gas and oil are phased out, the energy companies' margin pool shifts. His read: electricity prices stay relatively consistent for the next three to five years, gas and oil step up, and the next tipping point arrives in roughly five years.

A farm with a paid-off solar asset by that point is insulated. If grid prices step up another 300% as they did in the last crisis, the savings on a self-generated kilowatt-hour step up by the same factor. The 50,000 kWh sizing — rather than a tighter 37,000 kWh match — is the hedge that captures that upside instead of leaving it on the table.

How KMM works with farm clients

The approach on this project is the one we apply across the farm portfolio: model the economics before specifying hardware, oversize against future demand where the roof and grid connection allow, secure the right export route, and stay with the client through commissioning and tariff negotiation rather than walking away at handover. AIA capital allowances and the appropriate UK grant route are factored into the payback model up front, not bolted on afterwards.

If you run a UK farm and want the same honest, ROI-led conversation Kieran had on site — including a like-for-like payback model on your own consumption data — book a fully funded survey at our quote page.