Short answer: Greenhouse electrical demand must be calculated from the final equipment list, voltage, phase, frequency, motor starting method and operating sequence. Buyers should separate normal loads from critical loads that need backup power, such as irrigation, hydroponic circulation, controls, alarms and emergency ventilation.
A naturally ventilated film greenhouse and a climate-controlled hydroponic greenhouse of the same area can have very different power requirements. Fans, pumps, heaters, screens, roof motors, dosing systems, water treatment, lighting and cold storage all change the load. Ask for an equipment schedule instead of a single watts-per-square-meter assumption.
| Equipment group | Information to record |
|---|---|
| Ventilation and cooling | Fan, pad pump, circulation fan, fog pump and vent-motor quantities and ratings. |
| Irrigation and fertigation | Raw-water, irrigation, dosing, mixing, drainage and recirculation pumps. |
| Heating | Boiler auxiliaries, circulation pumps, electric heaters, valves and control loads. |
| Automation | Controller, sensors, actuators, network devices, alarms and remote-access equipment. |
| Water treatment | Feed pump, high-pressure pump, dosing, ultraviolet, ozone or other treatment equipment. |
| Crop systems | Grow lights, nursery equipment, conveyors, cold rooms or packing-area loads when included. |
Provide the available voltage, frequency, single- or three-phase supply, earthing method and local electrical code. Motors and control components should match the project supply. The buyer should also confirm who supplies transformers, main distribution panels, cables outside the greenhouse, generators and local inspection.
Motor starting can create a higher short-duration demand than normal running. Large fans and pumps may need staged starting, soft starters or variable-frequency drives depending on design. The control strategy should identify which equipment can operate together during the hottest or most demanding condition.
Not every load must run during an outage. Prioritize equipment whose failure can quickly damage crops or nutrient systems. Depending on the project, critical loads may include hydroponic circulation, irrigation control, climate controller, alarms, selected fans, vent operation, dosing, water-treatment controls and communication. The backup plan should include fuel, automatic transfer, manual procedures and tested runtime assumptions.
Every automated system needs a manual or safe-failure strategy. Ask what happens when a sensor fails, communication stops or the controller loses power. Operators should know how to open vents, run pumps or shut down equipment safely. Surge protection, lightning protection and stable earthing should be reviewed for the local site.
Final electrical equipment schedule
Single-line diagram and distribution-panel scope
Motor and pump data sheets
Control input-output list
Cable and protection schedule within the supplier scope
Critical-load and backup-power list
Commissioning, alarm and emergency-operation checklist
There is no reliable answer from area alone. The calculation needs the final equipment list, ratings, operating sequence and local supply.
Backup needs depend on crop risk, local grid reliability and critical equipment. Hydroponic circulation and climate-control projects often require a documented outage strategy.
They should not be assumed to do so. Staged starting and the control sequence should be reviewed with the electrical designer.
The quotation must define the boundary between greenhouse equipment, internal panels, site distribution, transformer, generator and local installation.
Review the greenhouse intelligent control system and the commissioning checklist.
Send the equipment scope, voltage, phase, frequency and grid-reliability information through the contact page for a preliminary electrical-load list.