Commercial solar for horticulture.

This page is for commercial horticulture: glasshouse and controlled-environment growers, propagation and nursery operations, and the packhouses that grade, chill and pack the crop. These are production sites that happen to grow plants, and the electricity bill reads like one. Supplementary grow-lighting, climate control through heating, ventilation and CO2 dosing, irrigation and pumping, and packhouse refrigeration together draw a high, sustained load that runs across the year rather than in short seasonal bursts.

That is what separates horticulture from the wider agriculture sector next door. A barn, grain store or arable shed can sit cold and idle for months and export much of what it generates, so on a farm the sizing follows whichever building actually carries the load. A controlled-environment grower does the reverse: the plant runs to keep an environment stable around the clock, so the demand is heavy and continuous, and far more of the generation tends to be used on site. That is exactly the profile a commercial array is worth modelling carefully against.

Solar pays best when the electricity is used on site rather than exported, because a unit consumed behind the meter offsets an expensive import unit, while an exported unit is paid far less. The return therefore tracks how well generation lines up with demand through the day, and a controlled-environment grower lines up unusually well. Climate-control heating and ventilation, circulation and irrigation pumps, CO2 and dosing plant and packhouse refrigeration all draw steadily through the daylight hours, so a high share of what the array makes is swallowed straight into the site rather than spilled to the grid.

The honest qualifier is supplementary lighting, and it cuts the other way from the rest of the load. Growers light hardest in the darker months and often into the evening and overnight, which is precisely when the array is generating least, so that part of the demand is met from import rather than from the roof. It strengthens the year-round case for using power on site, but it does not align with solar generation hour for hour. Where a grower wants to push more of the daytime surplus into an evening or overnight lighting run, battery storage is worth looking at, and we model the real half-hourly profile, lighting schedule and seasonal swing before sizing anything rather than quoting a sector average. The same modelling drives the return and payback case, and where capital structure matters we set out the finance options for a system this size.

Horticulture sites tend to present a different roof to a farm. The packhouse, propagation block and ancillary buildings usually carry conventional flat or shallow-pitch steel-portal roofs that array cleanly, while a working glasshouse is a glazed structure that is rarely a candidate for panels itself, so the usable array area is typically the solid-roofed buildings and any suitable adjacent ground rather than the growing houses. Where the packhouse runs a heavy chilled or cold chain, the load and self-consumption picture is close to what we model for food and drink processing and cold storage sites. As an indicative orientation only, sites in this sector tend to fall in a medium-to-large band, reflecting the spread between a single packhouse and a large multi-house grower with substantial ancillary roof. Treat that as a sense of scale and nothing more. It is not a quote, and the real figure comes from the on-site survey and the PV*SOL model, sized to the load the site actually carries rather than to the area on top of it.

Self-consumption drives the return here, and it tends to read more strongly than on a typical farm. Because the return on a horticulture array is driven almost entirely by how much generation is consumed behind the meter, a holding that runs heavy year-round demand keeps far more value on site than a farm building that sits cold for half the year and exports its surplus at a fraction of the import price it would otherwise offset. The steady climate-control, pumping and refrigeration baseload means a larger share of every generated unit lands against an expensive import unit rather than a low export rate, and that self-consumption ratio is the single biggest lever on the case. We model payback on the conservative self-consumption figure for your actual half-hourly profile rather than a sector average, and we show the import offset and any export value separately so the assumptions behind the number are visible and yours to challenge. None of that is a promise. The figures are modelled, not guaranteed, and they move with your tariff, your generation year and how the lighting schedule sits against the array across the seasons. The payback and return guide explains the method we use, and the ROI and payback guide sets honest expectations by load type before any figure is attached to your specific site.

There is a seasonal twist worth pricing into the case. A grower lights least in the long summer days, exactly when the array generates most, so the months of strongest generation are also the months of lowest lighting demand, and that is when a daytime surplus is most likely to spill to export. The summer cooling and ventilation load takes back some of that surplus, but where the model shows meaningful export in the bright months, an export-limitation scheme under G100 or a battery to carry midday output into the evening lighting run both come into the sizing conversation. We model that seasonal swing explicitly rather than averaging it away, because a horticulture profile that looks self-consuming on an annual average can still export hard for a run of summer weeks.

How the spend is structured moves the net cost as much as the headline price. A solar array on a commercial building generally qualifies for capital allowances, and the way the investment is financed against the energy saving changes the cash position in the early years, so two sites carrying the same array can land on very different net figures depending on how each is structured. We set those options out under commercial finance rather than fold them into a single number, because the right structure depends on your accounts and your appetite for capital outlay, not on a default we apply to everyone. The generation figure itself is a modelling output rather than a rule of thumb: we confirm the expected yield in PV*SOL against your exact roof pitch, orientation and the shading thrown by glasshouse runs and water tanks, and we treat that model as a starting point we test rather than a guaranteed annual output. The drone survey fixes those physical variables before the model runs, which is why we will not put a figure to a horticulture site until it has been measured.

The works sit over a growing operation that cannot simply stop. A glasshouse holds its environment around the clock and a packhouse runs a cold chain, so the installation programme is built around your growing and packing calendar rather than imposed on it, and the CDM 2015 duties under which the project runs are what keep a roof installation safe over occupied, plant-heavy buildings where ventilation, dosing and refrigeration plant stay live. On the network side, a system above 50 kWp needs a G99 connection agreement with your network operator, which across Yorkshire and northern Lincolnshire is Northern Powergrid, and that agreement is usually the pacing item rather than the roof works. We lodge it early and run the design alongside it so the connection position is known before we commit dates to your site.