We spent approximately €135,000 over seven years to eliminate on-site fossil fuels at AgriData's Tipperary office. This page is the honest cigarette-packet maths behind that decision — the payback math, the three defensible framings, the benefits the money number doesn't capture, and the one-sentence answer at the end for anyone who asks whether we'd do it again.
AgriData's Tipperary office — restored mid-1800s farm buildings on the Smith Barry Estate at Cluen, Bansha. The 2020 wind turbine stands in the yard as the honest reminder it was always meant to be; the solar PV covers the roof slopes; the forestry behind feeds the house's wood gasifier. Every figure on this page comes out of this place.
The two columns above are totals — this is what they are made of. The counterfactual column lists what the business would still be buying every year if nothing had changed, priced at November 2026 Irish rates. The reality column lists what has actually replaced it. Nothing is hidden; nothing is averaged away.
The headline number is €135,000 of capital across the seven years, 96.2% of it self-funded from company reserves and €5,298 from a single SEAI Non-Domestic Microgen grant on the 2024 solar PV expansion. But a chunk of that spend wasn't really a sustainability decision — it was baseline infrastructure that would have been installed anyway, in some form, to make the spaces usable.
The vehicle costs don't appear in this ledger because we were going to buy replacement vehicles anyway. The Tesla Model Y (2023, replacing a Mercedes GLC diesel) and the VW ID Buzz (2024, replacing a Ford Transit Connect) were running-cost comparisons against their fossil equivalents, not sustainability line-items. Their contribution to the picture is on the savings side — they stopped the diesel bills — not on the capital side.
These are the three cost lines the transition made disappear or dramatically reduce, priced at November 2026 Irish retail rates. The solar figure is what our Huawei FusionSolar monitoring system reports for 2025. The kerosene and diesel figures are the counterfactual: what we would be spending now, every year, if nothing had changed.
One subtlety worth naming: electrifying the heating and transport added about 15,000 kWh/year of new electricity demand. Some of that is covered by our own solar generation (which is why the FusionSolar €6,400 figure is a net benefit, not a gross one), and some is bought from the grid. The €18,000 figure doesn't double-count — it adds the three savings cleanly — but a fully-netted "like-for-like" comparison lands slightly lower, which is reflected in the third framing below.
There isn't one "correct" payback period for a project like this — there are honest answers to slightly different questions. These are the three we think bear scrutiny.
If forced to pick one number for a one-line answer: approximately seven years at today's prices. It sits in the middle of the three framings, admits both the arithmetic and the real-world messiness, and doesn't claim too much or short-change the real work.
One nuance worth owning rather than hiding: fuel prices in 2018 were about half today's — kerosene around €0.65/litre, diesel around €1.35/litre. Our lived payback over the actual seven years was slower than the today's-prices calculation suggests, because the early years saved less in cash terms. So the "seven years at today's prices" headline is really a statement about the resilience of the investment at current energy costs — which happens to be the exact question anyone considering a similar project today is actually asking.
A pure cash-payback calculation strips out everything that isn't a direct Euro saving. Two of the most valuable outcomes of this project aren't in the €18,000 figure at all. Honest accounting acknowledges them in a separate column, not by inflating the main number.
The alternative to those 7 space-conditioning heat pumps wasn't "oil boilers for the same rooms" — it was "oil heating plus a separate air-conditioning plant for summer." Print rooms, boardrooms, vaulted training spaces need cooling in modern working conditions. The heat pumps collapse two systems into one: one install, one commissioning, one maintenance contract, two seasons of comfort. An honest counterfactual would have added at least €15–20,000 of air-conditioning capital and the ongoing cost of running it. None of that appears in the payback number because it was never a direct substitution — it was a two-for-one that quietly didn't need to be funded.
The 2022–23 fossil-fuel price spike doubled kerosene and nearly tripled diesel over a six-month window. Any Irish small business running on oil heating and diesel vehicles took that hit directly to the bottom line; many are still recovering. Our site barely registered the event because the input to our energy stack was almost entirely sunlight, with a small residual grid draw. That's a real, cashable form of risk reduction — not just carbon, but balance-sheet resilience, with the receipts already in hand.
And the forward view is harder still: our Electric Ireland Nightsaver autoproducer tariff is contractually fixed until 30 June 2028. We know what the next twenty months of our electricity bill will look like. Anyone still buying kerosene and diesel for the same period knows only what today's price is — and the market has moved by double digits on less provocation than it is likely to see over the next two years.
Second of November, 11:50 in the morning. Grey Tipperary sky, 3–11°C, early winter proper. The depth of the solar off-season by every ordinary assumption about Irish weather.
And the system is quietly pulling 9.637 kW off the panels, running the whole building on 2.017 kW, charging the battery at 4.943 kW, and pushing 2.677 kW back out to the grid. By 11:50am, the day has already earned €3.30 of revenue.
If someone asks what Irish solar does in November, the honest answer isn't an argument. It's this picture, with the clock in the corner and the arrows pointing to the grid.
Huawei FusionSolar app, Monday 2 November 2026, 11:50am. Live data from AgriData's business meter.
The compressed version of this whole page, for anyone who prefers to see trade-offs in four quadrants rather than seven sections of ledger. Nothing here is spin — the weaknesses and threats are listed with the same honesty as the strengths.
Seven years in, with the receipts on the page and the November-morning monitoring data on our phones, there is no scenario in which we would un-make this decision. The payback math is defensible. The resilience benefit has already been collected on. The two-for-one of cooling-in-the-same-box is a quiet gift that keeps on giving. And the quality of the working environment — air that moves properly, heating that just works, vehicles that start every morning for a tenth the fuel bill — is a different, non-financial dividend that doesn't appear in any ledger.
If anything, the honest regret is that we didn't move faster between 2018 and 2022. The best year to have done this was always three years earlier than the year you're reading about it.
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David Mullins and Norrie Mullins · AgriData Ltd, Bansha, Co. Tipperary · First published 2 November 2026