It depends on the model. Some use very little electricity, while others use more. Cat water fountains are a great way to keep your cat hydrated, and they come in a variety of shapes and sizes. Some models use more electricity than others, so it's important to do your research before you buy one. If you're looking for a low-powered fountain, I recommend the Drinkwell Pagoda Fountain. It uses less than 5 watts of electricity, which is about the same as a nightlight. And it comes with a free 1-year replacement guarantee!

There is no definitive answer to this question since it largely depends on the specific model and make of cat water fountain. However, most cat water fountains use relatively low levels of electricity - usually on the order of just a few watts. So, unless you have a very large or power-hungry fountain, the added cost to operate one should be minimal.