Wild About Renewables: Page 3 of 5

Then we read Mick Sagrillo’s article on wind generators in HP90. After some more research, we decided to try a Bergey XL.1 and an African Wind Power (AWP) 3.6. We had some more towers manufactured and got the appropriate development permit for adding two wind generators. I didn’t find the Bergey to be well suited for our low wind-speed area, and it was hard to incorporate into the 48-volt system.

The Big Revamp

We got to the point where I realized that I needed to do a major revamp of our system. The regular electrical disconnects and wiring methods took up too much space and were too cumbersome to work with, so we redid our whole system with the OutBack AC and DC disconnect boxes. What an improvement! We also went to Rolls/Surrette batteries since they were the ones that I would normally be selling.

We replaced the Xantrex SW5548 with two OutBack FX2548Ts, since they had better motor-starting characteristics and a much better sine wave. The original PV charge controller was replaced with a Solar Converters unit and then with the OutBack MX60 controller. The H80 was rather noisy in high winds, so I replaced it with a Aeromax Lakota, which was much quieter, but due to our low average wind speed, it does not generate very much electricity on our site.

I sold most of the solar-electric panels we had, and purchased new modules that allow the maximum use of solar energy from our roof structure. The PVs overhang the roof edge and provide some shade for the solar hot water collectors in the summertime when we do not want heat from them. This setup has worked quite well.

We also decided on a second AWP 3.6 to go on a taller tower. We were able to get a used, 80-foot (24 m) freestanding tower from Robert at Abundant Renewable Energy along with the second AWP 3.6. Since we are in town, the original height restriction was 50 feet (15 m), but we were able to get a permit to go to a 100-foot (30 m) tower height and have a maximum of three wind generators. The town of Didsbury has been really good to deal with in terms of our renewable energy system.

Hot Water

Our solar hot water system consists of six flat-plate solar collectors on the south wall of our house. We wanted to use solar energy to heat the slab of our home. As the sun heats the collectors and the temperature rises to a setpoint of 100°F (38°C), an Aquastat controller turns on a DC pump that is powered by a dedicated PV module. The flow is then modulated according to the temperature of the collectors. If the temperature in the collectors drops below the set point and differential, the pump is turned off until the collectors are warm enough again.