Sun brings savings through solar water heater

Last October, we installed a solar water heating system on our home. It has been about 10 months and I thought this would be a good time for a promised update. Overall, we are very pleased with the results.

Our system was manufactured by Heliodyne in Richmond, Calif. I like that it is made in the U.S. and is relatively local. It consists of one 4-foot-by-10-foot flat plate collector on the roof and a 75-gallon water tank (with natural gas backup) in the garage. Space is at a premium in our two-car garage, since we actually park two cars and a bunch of other stuff in it, and the single-tank system has the same footprint of our previous 50-gallon tank.

The single tank is just like a standard, well-insulated, gas-fired water heater with some extra connections to accommodate the solar component. It serves as a backup and is set to automatically turn on just like a regular water heater when necessary. During the summer, it is a rare occasion, but during winter it regularly supplements the reduced solar contribution.

There are two ways to monitor the system's performance. First, the controller has software that provides information directly to our home computer. Secondly, I compare our bills from Southwest Gas. Neither provides a precise account of actual savings because there are many factors that blur the data. I know how much energy the system collects from the sun, but how much of that solar energy is used to offset our use of natural gas is not as clear because we also use natural gas for cooking, space heating and clothes drying. Plus, the new system is set to provide hotter water than we had before, something we enjoy quite a bit.

The bottom line is that even with the water set to a higher average temperature, we have cut our use of natural gas considerably. Average yearly consumption for the entire home is expected to be about 33 percent lower, with a monthly maximum reduction of 63 percent so far. Although I do not know exactly what the percentage is for just the hot water, I can say that the system's performance has so far exceeded its official rating by about 20 percent.

Unlike photovoltaic systems that can send excess energy back into the grid for credits that can be redeemed in the future, solar hot water is a "use it or lose it" resource. There is no way to shove that excess thermal energy back into the pipe to the benefit of Southwest Gas or its other customers. In general, those who use the most hot water, whether larger families or commercial businesses, will get the greatest bang for their solar-water-heating buck. Our particular situation is the opposite and therefore more of a worst-case scenario when it comes to payback. No matter how you slice it, though, a solar water heater is the only kind I know with any payback at all.

Payback comes in many forms, and the simple savings is by far the least important. Natural gas is now very cheap, because of the increasingly widespread practice of hydraulic fracturing, otherwise known as fracking.

The process injects a toxic brew of chemicals into the ground, fracturing the rock to release gas and other by-products. It is far from benign. Aquifers are being poisoned forever and an increasing number of people, our fellow citizens, friends and family, are getting seriously ill as their property values plummet to zero.

My computer shows a chart of red bars indicating how much energy our system has produced. Every increment on each of those bright red bars means one less unit of natural gas burned, one less bit of water poisoned, and fewer friends and fellow human beings damaged by the relentless quest for fossil fuel profit at any cost. There are many who can afford solar water heaters. Imagine the impact we will have when they are on every rooftop!

This is a good time to install a system. Incentives are strong now, but they come and go. If you can afford it, please invest in our collective future. That is what green living is all about.

Steve Rypka is a green living consultant and president of GreenDream Enterprises, a company committed to helping people live lighter on the planet. For more information and links to additional resources relating to this column, or to reach Steve, please visit www.greendream.biz.