Greenhouse Heating Cost Calculator
Estimates the daily electricity cost to heat a greenhouse based on its size, heating intensity, and your local energy rate. Use it when budgeting for winter growing seasons or comparing heating system options.
About this calculator
Greenhouse heating cost is determined by four factors: the floor area being heated (m²), the heating rate required to maintain target temperatures (W/m²), the number of hours the heater runs per day, and the local electricity tariff ($/kWh). The formula is: Daily Cost ($) = (greenhouseArea × heatingRate × operatingHours × energyCost) / 1000. The division by 1,000 converts watt-hours to kilowatt-hours, which is the standard billing unit for electricity. A higher heating rate is needed in colder climates or for heat-loving crops. Knowing this figure helps growers decide whether supplemental insulation, thermal screens, or alternative fuels would reduce operating expenses significantly.
How to use
Suppose your greenhouse is 200 m², your heating system delivers 50 W/m², it runs 10 hours per night, and electricity costs $0.15/kWh. Plug into the formula: (200 × 50 × 10 × 0.15) / 1000 = 150,000 / 1000 = $15.00 per day. Over a 90-day winter season that totals $1,350. Adjust the heating rate downward if you add insulation, or change operating hours to model a thermostat-controlled system.
Frequently asked questions
How do I calculate the heating rate needed for my greenhouse in winter?
The heating rate (W/m²) depends on the temperature difference between inside and outside and the insulation quality of your structure. A common rule of thumb for a single-layer polycarbonate greenhouse is 50–80 W/m² in temperate climates. You can also use heat-loss calculations based on the U-value of your glazing material multiplied by the design temperature difference. Consulting local agricultural extension data for your climate zone gives the most accurate figure.
What energy sources are cheapest for greenhouse heating?
Natural gas and propane are typically cheaper per unit of heat than electricity in most regions, making them popular for large commercial greenhouses. Biomass boilers and geothermal heat pumps offer low long-term running costs but have higher upfront investments. Electricity becomes competitive when combined with high-efficiency heat pumps (COP 3–4) or when surplus renewable energy is available. Always compare costs in $/kWh-equivalent before choosing a system.
How can I reduce my greenhouse heating costs without sacrificing crop quality?
Thermal screens or bubble-wrap insulation on glazing can cut heat loss by 30–50%, directly reducing the required heating rate. Setting night temperatures to the minimum crop threshold rather than a comfortable daytime level saves significant energy. Sealing gaps around doors, vents, and foundations prevents cold-air infiltration. Grouping cold-tolerant and warm-requiring crops into separate zones lets you heat only the warmest zone intensively.