Solar Thermal application for heating indoor pools

About six months ago we did the start up of a solar thermal system to heat our indoor lap pool, leisure pool, and domestic hot water for showers. The solar system is in addition to natural gas boilers. The system is very sophisticated, has 100 4'x10' panels, and its own website for monitoring energy usage and controlling the system. The reason for getting the system was to cut down on our monthly gas bills and was to be mostly paid for by grants. During the initial planning it was determined that the return on investment (from our organization) would be shorter than the warranty period of the panels, therefore the investment made sense.

The system has been operational for about 6 months now. In those 6 months the system has not been perfect as there have been a variety of small changes to add more efficieny. Most of the kinks are ironned out and we will likely see more efficiency out of the system when the weather outside is colder.

When I last did the math, the initial investment will be cutting it close to the warranty period of the panels. That will be about 15 years. For a full payback, including the money from the grants,assuming natural gas prices stay the same (which they won't), then we will have to wait over 80 years.

It is a very neat system and it does what it is supposed to do, but it is not financially feasible. If you want to spend more money for state of the art technology for pool heating or you want a LEED Platinum certfication then it will be a good investment for you. However, if you are trying to cut costs during difficult financial times, this is not the answer.

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Permalink Reply by www.indeksolar.com ; John Hurt on August 11, 2010 at 4:05pm

Hello Ben,
You did not give enough details on the water surface areas of the pools and if they are covered.What was the solar heating system cost and cost payback analysis.Is this a Viessmann system? What was the total amount of incentives from the government,etc?
Where is the project located?
Kind Regards,
John Hurt
WWW.INDEKSOLAR.COM

Permalink Reply by Ben Goldstein on August 11, 2010 at 4:24pm

Hi John,

I have got two very average municipal pools. The lap pool is 205,000 gallons with a depth range of 4' to 12' and a surface area of 3,400 square feet. It has a target temperature of 82 degrees. The leisure pool is 65,000 gallons with a depth range of 0' to 5' and a surface area of 2,800 square feet. Its target temperature is 86 degrees. The air temperature is kept at 88 degrees and humidity between 35% - 50% during operational hours. At night we cover both pools with thermal blankets which automatically drops the humidity to 20%. The total cost was about $400,000 and in the 6 month period, we estimate savings at $2,500. The state grant was $326,000. We are in Gunnison, CO, USA. I do not know what a Viessmann system is, so I assume that we do not have it.

Permalink Reply by Jody Gorran on August 16, 2011 at 10:07am

Ben, I noticed in your description of the solar thermal system that it also provided for domestic hot water for showers. Since solar thermal panels, ie collectors meant for domestic hot water production are generally glazed with copper absorber plates or made with evacuated tubes, were the same type or design of solar thermal panels used for heating the pool as well?

From a cost perspective and performance perspective, "polymer, unglazed" solar thermal collectors for heating swimming pools are the most cost effective use of solar technology today. They provide economic and energy saving benefits at literally one-tenth the cost of solar thermal for domestic hot water or solar pv for generating electricity. Visit www.hybridsolarpoolheating.com