Greenhouse Solar Energy: Irrigation, Ventilation and Lighting

Greenhouse solar energy means meeting a greenhouse's electrical loads, such as irrigation, ventilation, lighting and packing, with solar panels. Because protected cultivation is so widespread in Antalya, the right question is not "can panels be installed?" but "where can panels go to produce the most without harming the crop?" The answer is usually not the greenhouse roof, but the buildings and open land next to the greenhouse. In this article we cover the load profile, shading design and Antalya-specific risks.

What are the electrical loads in a greenhouse?

Before connecting a greenhouse to solar energy, you need to know which device runs when. Electricity consumption varies widely with greenhouse type, crop and season; the table below shows the nature of the loads and their overlap with solar production in general terms.

Because irrigation pump and ventilation loads run during the day, they overlap naturally with solar production. Loads that run at night are either met from the grid or supported by a battery; a battery investment only makes sense if the night load is large.

Shading design in greenhouse solar energy

Covering the greenhouse roof with panels cuts the light passing through that surface to the plants. For high-light crops such as tomatoes, peppers and cucumbers, this means a direct yield loss. For that reason, the first rule in greenhouse solar energy projects is that the panel must not take the crop's light.

The locations preferred in practice are as follows:

• Packing shed and storage roofs: The roof of a fixed structure beside the greenhouse creates no shading problem and is more suitable structurally.
• Vacant land beside the greenhouse: A south-facing tilted array on the ground gives optimum production and is easy to maintain.
• Around the water tank and pond: A system built at the same point as the pump shortens the cable run.
• The north face and side walls of the greenhouse: Considered only at points that do not affect the crop's light, and with an agronomist's approval.

For operations that want to place panels partly on the greenhouse roof, sparse-layout or semi-transparent solutions exist; however, these must be verified agronomically together with the crop's light requirement. Row spacing is also always calculated in the design so that the arrays do not shade each other or the greenhouse itself. For a ground system beside a multi-span greenhouse block, the distance between rows must be set according to the low angle of the winter sun.

Hail, storm and wind risk in Antalya

On Antalya's western coast, especially around Kumluca, Finike and Demre, hail, storm and tornado events have damaged greenhouses. In January 2019 about 1,000 decares of greenhouses were damaged, and in October 2020 hail and a storm hit Kumluca. The fastest wind in MGM (Turkish State Meteorological Service) records is 43.2 m/s. A numerical hail risk cannot be given for the region; however, these events show that the panel structure must be designed for wind load.

In typical panel datasheets, wind load is stated as 2400 Pa and snow load as 5400 Pa. For ground systems, in addition to these values, the steel structure, foundation footings and fasteners must be calculated for the site wind load. If installation is not carried out in line with the manufacturer's installation manual, the warranty may also end. Insurance coverage should be assessed separately too; for details see our solar plant insurance article.

Seasonal gap: crops in winter, production in summer

In Antalya the greenhouse season runs mainly in the cooler months, whereas solar production peaks in summer. According to PVGIS data, 1 kWp of panels in Antalya produces 168 kWh in July and 99 kWh in December; that is, December production is about 41% lower than July (calculation). This should be watched closely in systems sized on an annual net metering logic.

There are two routes in design: size the system for the winter months when consumption is heavy and feed the summer surplus to the grid, or size it for annual consumption. Which one suits depends on the subscription type, the contracted capacity and the capacity limits defined in the regulation. For agricultural irrigation subscriptions, capacity of up to twice the contracted capacity is foreseen; however, you need to confirm with the distribution company which subscription group your greenhouse electricity falls under.

Example sizing calculation

Let us proceed with a hypothetical example. Suppose the irrigation pump is 5.5 kW and runs an average of 6 hours a day: 33 kWh. Suppose the total power of the ventilation and circulation fans is 4 kW and they run about 5 hours a day: 20 kWh. Total daily consumption comes to about 53 kWh. If we assume the system runs at this load for about 180 days a year, annual consumption is 9,540 kWh.

Dividing this consumption by the 1,656 kWh/kWp that PVGIS gives for Antalya city centre yields about 5.8 kWp. With 605 W panels, this corresponds to 10 panels (6.05 kWp). In a real project, this value is corrected for shading, tilt, cable losses and the timing of the load. The figures are only to show the calculation method; they vary with the actual greenhouse load.

System selection and tariff context

For loads concentrated in the daytime, a grid-connected (on-grid) system is the simplest solution; for details you can look at our on-grid systems page. For remote greenhouses with weak grid access, a hybrid or off-grid solution comes into play. When deciding which system suits, always work out the total power and simultaneity of loads such as the irrigation pump, ventilation and cold room; high starting currents also influence the inverter and contracted capacity decision.

For a grid-connected greenhouse system, the application in Antalya is made through AEDAŞ's (the regional electricity distribution company) LUS platform; since 01.10.2023 AEDAŞ accepts unlicensed generation applications only through this portal. If the system is under 25 kW, the simplified procedure applies and the system cannot exceed the subscriber's contracted capacity. For larger greenhouse operations, a contracted capacity increase and transformer capacity are also assessed separately. Process steps such as the connection approval letter (çağrı mektubu), project approval and commissioning acceptance work the same way for these facilities; a plant operated without acceptance can be disconnected, so the system must not be energised before acceptance.

On the tariff side, with effect from 4 April 2026, EPDK (Turkey's Energy Market Regulatory Authority) raised retail sales prices in the agricultural activity subscriber group by about 24.8%. Because tariff items can change over time, always run the payback calculation with the current tariff table. You can read our solar-powered agricultural irrigation article, where we cover pump and panel selection for solar-powered irrigation in detail.

Region-specific notes: Kumluca, Finike, Demre

In greenhouse operations in western Antalya, field and greenhouse are mostly intermingled; shed, packing and storage roofs are plentiful, while vacant land is limited. In this case the most practical solution is to use the roofs of existing buildings; on trapezoidal sheet roofs, clamp fixing allows quick installation without drilling the roof. The roof's load-bearing capacity must be assessed by a civil engineer; the distribution company and the municipality may also ask for a structural suitability certificate. For regional details you can look at our Kumluca and Finike greenhouse article and our Demre greenhouse solar panel article, which focuses on tomato greenhouses.

Maintenance and monitoring in a greenhouse environment

In greenhouses, residues from spraying and irrigation can build up a layer of dirt on the panel surface. Humidity and condensation raise the risk of corrosion at cable connection points. For this reason equipment with a suitable IP protection class should be chosen, and connectors and panel entries should be checked at least once a year. For surface cleaning, chemical-free methods recommended by the panel manufacturer should be used; for details you can look at our solar panel cleaning guide. A mobile monitoring system helps catch sudden drops in production early.

Conclusion

Success in greenhouse solar energy projects depends on placing the panel where it will not cut the crop's light, working out the load profile correctly and reflecting Antalya's hail and wind risks in the structural design. While daytime loads such as irrigation and ventilation overlap with solar production, night loads need a separate strategy. You can request a free site survey from Solar Nexo with your greenhouse's load list and land plan.

#Systems#Greenhouse Solar Energy#Protected Cultivation#Antalya Greenhouse#Greenhouse Solar Plant#Load Profile