Na Oiwi Olino

For those of you who missed it, here is my interview energy efficiency and sustainability on the Na Oiwi Olino radio show with Brickwood Galuteria and Kimo Kahoano.

http://www.streamaudio.com/listen/cox.asp?station=KKNE_AM&streamtype=archiveaudio&filename=NOO_2007-11-02.mp3

Using the sun's free energy

A while back I discussed how solar attic fans can help cool your homes and avoid or minimize the use of air conditioning systems. Based on some of the feedback I received, I realized there was a more basic system I should have started with. For those of you blessed to live in the southern half of the United States, and especially for those of you who live in Hawaii, solar water heating is the first thing you need to install.

Solar water heaters use the sun's heat to heat the hot water for your house. This allows you to essentially heat your water for free, which is significant since this is one of the largest energy uses in your home. During the day when the sun is out, the water passes through the tubes in the panels and heats up, going into your water heater for storage. If the water isn't at the desired temperature, the electric/gas back up will kick in to ensure you always have hot water. However instead of heating your water all of the time with electricity or gas, its only a very small portion of the time.

A typical solar water heating system installed will run you between $4,500 and $6,000, depending on your location and the size of the system required. Typically a family of four in a good solar zone can get by with an 80 gallon system and two panels. Don't sweat the details, a reputable solar contractor can size the system for you.

The best thing about it is that solar water heaters represent a great return on investment. They qualify for a 30% federal tax credit, and many states also offer state tax credits, and some utilities even provide rebates. In Hawaii, a family of 4 will typically see about a 3 year payback on a solar hot water system. In California its about 4 years.

When selecting a contractor, make sure they are licensed and have an established track record of installations. You want to be sure they have been in business for a while and know how to do these installations. I also highly recommend bottom connect systems (where the piping from the panel goes into the tank). This prevents thermo-syphoning at night where the hot water on top connect systems run back through the panel and cool down when the check valves fail.

Good luck, email me if you want more info.