News flash: Geothermal heat exchange systems ARE NOT a source of renewable energy. And it’s OK with me.

 

Lately there have been a number of articles and blogs questioning the efficiency and energy savings of geothermal (ground source heat pump) systems. Several of these articles “exposed” the shocking fact that these systems are not renewable energy sources like wind, solar and hydroelectric.

Why aren’t geothermal systems renewable? Seems the answer is because they use electricity. So, if that electricity isn’t generated by wind, solar or hydroelectricity, then it is probably using a non-renewable resource like coal, natural gas or nuclear to create electricity.

I installed a geothermal system two years ago, and I have been monitoring my energy usage to see how I’m doing in the energy saving department. The performance has been gratifying: reducing my overall energy consumption by 55%.

Now, I expect there will be future years where the savings go up a bit or down a bit, but I’m pretty happy with 55%.

Would I like to offset the electricity used to to run the two small Grundfoss pumps that circulate the fluid? Of course I would. But in the meantime, I continue to look at other easy wins to reduce electricity usage.

As for the performance of the geothermal system, I couldn’t be happier. Through a huge heat wave this summer with temperatures reaching into the low 100’s, and 98-degree days a regular occurrence, my actual electricity usage is comparable (a bit less actually) to pre-geothermal summers. And in spite of the heat, our home remains a comfortable 75-degrees or 78 –degrees, depending on the zone setting.

Of course, every home is a unique story. The contractor that installed our system was very experienced in geothermal design and installation. We did the whole insulation and interior/exterior sealing of the building envelope. Added humidification control for winter and summer, and introduced a fresh air vent, which has contributed to a comfortable indoor atmosphere.

But the bottom line is: the geothermal system is operating in a delightfully comfortable and efficient fashion….and it even heats the water for the whole house…no extra charge.