Solar panels for a hot tub

How much electricity does a hot tub use?

How much a hot tub uses depends on several things: the water temperature, the amount of water and how long you use it. Taking a rigid hot tub that is on continuously, keeping it warm takes about 6 kWh a day. Beside this you can see what that comes to per week and per month.

So a hot tub pushes your energy costs up. At an average price of 0.40 euros per kWh it costs an extra 16.80 euros a week (42 kWh x 0.40 euros).

What solar panels bring your hot tub

Now that you know how much a hot tub uses, you can see what heating it with solar panels brings: a lower energy bill, to begin with. Solar panels are also a clean way to generate energy and shrink your footprint.

How many solar panels does a hot tub need?

From the example above we know a hot tub uses about 2,200 kWh a year. To work out how many panels that takes, we use a panel rated at 430 Wp. Because the full rating is never reached, owing to the weather, we allow a correction factor of 85%, which gives 365 kWh per panel. The sum is then 2,200 / 365 = 6 solar panels.

So six panels cover a hot tub's consumption over a year. Please note: those six cover only the hot tub. Would you like your panels to cover the rest of the house as well? Then we would advise fitting more.

Read our blog "How many solar panels do I need?" to see how many are advisable in your situation.

Saving energy with your hot tub

Besides solar panels, there are other ways to save energy on a hot tub. A good insulated cover, for instance. The insulation of the tub itself makes a difference too: an inflatable hot tub will use more than one with insulated walls.