Despite the claims of heat pump sellers that say all kinds of crazy things, heat pump are not cheap to operate. Our favorite is that heat pumps “cost about a dollar a day to operate.” Let’s be clear: it’s not true. At a minimum, it’s very misleading.
You see, there are all kinds of caveats to these claims about when you can run your heater and how warm you can actually heat your pool to achieve that kind of operating cost. And it does not match up with how people actually use their pools and heaters.
I recently had a client with a solar electricity system call me with concerns about her utility bill. She hadn’t seen a big drop in her electric bill compared to last year. Because we have solar production monitoring installed at all of our installations, I was able to verify that the energy was right in line with expectations. So that left consumption as the likely culprit. Fortunately, we also have whole home consumption monitoring installed at this client’s home.
I suggested that she look at energy use, but she couldn’t think of anything that would cause her electricity to be so high, especially with her new solar energy system. I went to the house to investigate, but I already knew the answer. The consumption monitor showed a huge spike in electricity every morning that was sustained throughout the day. It was late November in Southwest Florida – and this is pool heating season!
Sure enough, the electric pool heat pump was set at 85ºF and we had been seeing some very cool nights. There was no question in my mind that this was the culprit. Since it was too cool to swim that week anyway, I suggested that she turn off the heat pump so we could see how her energy consumption changed. The difference was stark.
See the big change on the third day? I was there at about 10 am when we turned off the heater. See how the orange consumption graph hasn’t been nearly as high as the prior two days?
Check out the energy consumption (in kWh) for the last 14 days. After the heat pump was turned off the whole home energy use dropped by 40%! That’s huge!
What the heat pump energy use amounted to turned out to be closer to $2 per day, and we haven’t even reached the coolest part of the year. That’s double the operating cost advertised by some heat pump dealers. The cost adds up. Over the years the cost of heating a pool with electricity can exceed the cost of the heat pump itself!
That’s where solar pool heating comes in. Once the initial cost is paid, there is essentially no operating cost. You get a warmer pool every day of the year.
Don’t get me wrong – there is a place for heat pumps. They do a great job of heating small bodies of water for occasional use (think: spas). They also can, at times, get pools warmer than solar pool heaters. If you demand a certain temperature and have deep pockets, a heat pump may be a good option for you or could be added to a solar pool heater to get the best of both worlds. But be prepared to incur the operating costs, which often get hidden in electric bills, especially if you do not have energy monitoring at your home.
One way you can check your energy use is your utility company website. New smart meters make monitoring your energy consumption easier, and you can often spot the culprit pretty easy be figuring out what times you are using the most energy. The heat pump may just be your biggest energy user at times!