What a desk-based study is for
A feasibility study answers one question before anyone climbs on a roof: is solar worth pursuing on this holding, and on which buildings. It is built from data you already have, so it should be inexpensive to produce, and it should be clear about what it assumes.
What it needs from you
- Half-hourly electricity data for at least twelve months (from the supplier or the smart-meter portal) or twelve months of invoices.
- The tariff and any contract end date.
- Roof dimensions and orientation for each candidate building, from a sketch or aerial photo.
- The age and construction of each roof, including whether it is asbestos cement.
- The electricity supply: single or three-phase and the DNO area.
What it should produce
- A system size for each building, matched to the daytime load rather than the roof area alone.
- A generation forecast from PVGIS for the location and orientation; the regional figures are in PVGIS yields for farm roofs by region.
- The share of generation used on site, and the export left over.
- An indicative installed cost set against the official DESNZ baseline on the farm solar cost guide, with the site-specific items listed.
- The grid connection route and what the DNO will need (DNO grid connection for rural farm solar).
- The tax treatment of the capital spend (grants and funding).
- A list of the things the desk study cannot know: the roof, the structure, asbestos and the electrical condition.
What it cannot tell you
A desk study cannot see the roof. Whether the sheets are asbestos cement, whether the purlins can take the load and whether the electrics are in a state to connect are found by the farm roof survey for solar PV. Treat the numbers as ranges until that is done, and treat any study that gives a single payback figure without showing the tariff, the self-consumption assumption and the price basis as incomplete.
Questions for whoever produces it
- What does it cost, who carries it out and is any of it conditional on you buying the installation?
- Which data and tariff did it use, and can you see the assumptions?
- Does it model a battery or EV charging, or only the array?
- Does it say what it has not assessed?
Common questions
What is a farm solar feasibility study?
A desk-based analysis from half-hourly meter data and building dimensions that estimates system size, generation, the share used on site, indicative cost and the grid connection route before anyone visits. It cannot assess the roof or structure.
What data do I need to give?
Twelve months of half-hourly electricity data or invoices, the tariff, roof dimensions and orientation, the age and construction of each roof and the electricity supply.
Should a feasibility study give a payback figure?
Only with its assumptions shown: the tariff, the share of generation used on site, the export rate and the price basis. A single payback number without them is not worth relying on.