How much does the electricity cost for low voltage outdoor lights? Here is an easy answer, plus a way to calculate the exact cost of your own outdoor lights.

Here’s a rule of thumb: LED outdoor lights cost \$1/year to run from dusk to dawn every night. Yes, that’s all! That’s based on 3W LED landscape lights running an average of 10 hours per evening.

So if you have 10 lights on your landscape, a good guess is they cost \$10 per year if you run them from dusk to dawn every night. If you only run them from dusk to midnight, they’d cost even less.

Want the details? To start with, let’s find the cost per Watt. Imagine a 1 Watt light running from dusk to dawn every night all year. How much electricity would it use, and what would it cost? Let’s do the math!

• 1 Watt x 10 hours (dusk to dawn average time) = 10 Watt-hours per night
• 10 Watt-hours per night x 365 nights = 3,650 Watt-hours per year
• Divide by 1,000 to turn into Kilowatt-hours (kWh) = 3.65 kWh per year
• Off-peak electricity cost is 8.7 cents per kWh
• 8.7 cents x 3.65 kWh = 31.8 cents per year

All together, that works out to be less than 32 cents per Watt for a whole year of use from dusk to dawn. It also means a typical 2 or 3 Watt garden/path light would cost less than \$1 per year.

Now let’s look at the cost for an entire LED landscape lighting system. Let’s say you had 5 garden/path lights, 5 up-lights for trees, and 5 deck lights, all with typical LED bulbs:

• 5 garden/path lights at 2.8 Watts each = 14 Watts
• 5 up-lights for trees at 4.7 Watts each = 23.5 Watts
• 5 half-moon deck lights at 1.5 Watts each = 7.5 Watts
• 14 Watts + 23.5 Watts + 7.5 Watts = 45 Watts total
• 45 Watts x 10 hours per night = 450 Watt-hours per night
• 450 Watt-hours x 365 nights = 164,250 Watt-hours per year
• Divide by 1,000 to turn Watt-hours (Wh) into Kilowatt-hours (kWh) = 164.25 kWh per year
• Off-peak electricity cost in Toronto is 8.7 cents per kWh
• 8.7 cents x 164.25 kWh = \$14.29 per year

Your entire landscape lighting system of 15 lights running dusk to dawn every night would only cost \$14.29 per year total. That’s less than \$1 per fixture for the entire year. That’s not “pennies a day”, it’s “pennies a month”!

So don’t let the rising cost of electricity keep you from having lovely landscape lighting. For less than \$1 per year you can add beauty and safety to your property, and enjoy your outdoor living spaces more every night.