
How to reduce electricity consumption in your grow room
The cost of electricity is rising rapidly all over the world and increasing the cost of growing indoors. So what can you do to reduce the electricity costs?
The grow light consumes the most energy in the grow room
In your typical 4ft x 4ft or 1.2m x 1.2m tent the extract fan, circulatory fan and water or air pumps will consume between 15 to 30 watts each or about 70 watts in total. The grow light wattage to delivery a good yield will range from 400 to 650 watts, depending on the technology used. Therefore the power consumed by your grow light is about 80 to 90% of the total.
The cost of electricity varies in different countries and states so we use the average in the US and Europe to calculate the running cost of grow light types. The energy consumed by each grow light technology is calculated based on delivering an average PAR of 800 µmols/m²/second over a 4 x 4 grow area.
Comparison of the running costs for HID and LED grow lights in the US and EU
The most efficient grow light, the modern LED grow light is on the bottom row. The right hand column displays the extra money you have to spend each year on electricity at todays rate.


LED grow lights are much cheaper to run than HID grow lights
It now takes just one year to recover the cost of purchasing an efficient LED grow light compared to a Metal Halide and High Pressure Sodium system. The savings will be even greater if you count the replacement cost of bulbs and air conditioning of the additional heat produced by HID systems.
Guide to upgrading from HPS to LED grow lights
It takes longer to recover the money if you are upgrading from an LED grow light purchased in the last few years i.e. before about 2020 but it is still worth it.
Link to US electricity cost per state: https://www.bls.gov/regions/midwest/data/averageenergyprices_selectedareas_table.htm
Link to European electricity cost per state: https://ec.europa.eu/eurostat/cache/infographs/energy_prices/enprices.html?geos=&product=6000&consumer=HOUSEHOLD&consoms=4161903&unit=KWH&taxs=I_TAX,X_TAX,X_VAT&nrg_prc=NETC,NRG_SUP,OTH,TAX_CAP,TAX_ENV,TAX_NUC,TAX_RNW,VAT¤cy=EUR&language=EN&detail=0&component=0&order=DESC&dataset=nrg_pc_204&time=2021S2&modalOption=0&chartOption=0&precision=1&modalOpen=0&modal=0&modalLineOption=0
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