Running your grow lights should not cost more than a few dollars per week. However, every setup is different. You may worry that leaving lighting on for over half the day may drive up your electricity bill.

Luckily, most indoor setups will not severely impact your budget. Unless you have a large grow room with dozens of lights, you can expect to spend just pennies per day.

So, how much do grow lights cost to run? Use the following guide to calculate the cost of running your grow lights and find ways to increase your energy savings.

You should also read: Best Grow Lights For Beginners

How Much Electricity Do Grow Lights Use?

The cost of running grow lights mostly depends on the watt of the bulbs and your local electrical rate. A 600-watt LED bulb consumes the same amount of power as a 600W HPS bulb.

How Much Electricity Do Grow Lights Use?

You can estimate the cost by determining the power consumption of your grow lights. Divided the wattage of the bulb by 1000 to determine how many kilowatts per hour it consumes.

A watt (W) is a unit of measurement for electrical power. A kilowatt-hour (kWh) measures the consumption of energy. 1 kWh is the energy consumption for a 1,000-watt device operating for one hour. A 60W incandescent light bulb consumes 0.06 kilowatts per hour (60/1000 = 0.06).

Multiply the consumption of the light bulb by the number of hours per day that you plan on leaving the light on. For example, if you leave the lights on for 18 hours, multiply the kilowatts consumed per hour by 18. A 60W bulb left on for 18 hours per day would consume 1.08 kWh (0.06 x 18 = 1.08).

Multiply the kilowatt-hours by your current electric rate. Your rate is found on your electrical bill.

The average residential electricity rate is 13.29 cents per kilowatt-hour (kWh). Using the previous example, a 60W bulb would cost $0.1435 per day (0.1329 x 1.08 = 0.1435).

LED

LED grow lights are the most efficient option and cool to the touch. An LED light bulb does not produce heat, which eliminates the need for fans that add to the cost of running grow lights. An LED grow light should also last much longer compared to other bulbs, but also tend to cost more.

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HID

HID grow lights are the traditional grow lights found in many indoor gardens. HID lights offer the brightest light output and a broader light spectrum.

HID grow lights come in two varieties: HPS and MH. High-pressure sodium (HPS) bulbs provide a broader spectrum of light. An HPS light is a common sight in a grow tent, as it is useful for the flowering cycle.

Metal halide (MH) bulbs are better suited for the vegetative cycle. However, both varieties emit more heat compared to other types of bulbs.

The heat produced by an HID grow light often requires ventilation. Using fans increases the cost of running your grow lights. If you add fans, include the wattage of the fans in your total when calculating your electricity costs.

CFL

A compact fluorescent lamp (CFL) is a common choice for growing plants indoors. Fluorescent grow lights are cheaper and produce less heat compared to an HID bulb.

A fluorescent light bulb is also likely to die more quickly, requiring more replacement bulbs. Depending on the size of your setup, you may not need fans to control temperature.

Frequently Asked Questions

Here are the most common questions people have when it comes to the cost of running a grow light.

How Much Do You Pay for Electricity?

Rates are listed as the cents charged per kilowatt-hour (kWh). The average in the US is 13.29 cents ($0.1329). However, rates vary significantly from one state to the next and even from town to town. 

Hawaii residents pay 30.55 cents per kWh, which is the highest rate in the US. Louisiana has the lowest rate, charging an average of 7.01 cents per kWh. Outside of the US, Germany has the highest electricity rates. The average residential rate was 36 cents per kWh.

What’s the Wattage of Your Grow Light Bulbs?

Multiply the watts of your bulbs by the number of bulbs to determine the total wattage. For example, if you have 6 40-watt CFL tubes, your grow lights require 240 watts of power (6 x 40 = 240).

What Are the Most Expensive Grow Lights to Run?

HPS bulbs are the most expensive to run, as they may require the use of ventilation fans. They are also the least efficient option, requiring you to replace the bulbs more frequently.

Can You Turn Grow Lights Off to Save Money? 

You can turn your grow lights off to conserve energy and save money, but your plants may not grow as quickly. Leaving your lights on for 12 to 18 hours per day promotes faster plant growth, especially during the flowering stage. However, most plants only require 8 to 10 hours of light.

Conclusion

The cost of running your grow lights depends on the total wattage of all the bulbs used. You also need to include the cost of ventilation fans, which are often needed when using HID bulbs.

Multiply the total wattage of your setup by the number of hours they run each day. Depending on the growth stage, you may run your lights for 12 to 18 hours. Multiply the total energy consumed each day by your electricity rate. You now have an estimate for the cost per day to keep your lights on.

Further reading: Can You Grow Your Plants With Regular LED Lights?