Off Grid in Arkansas: Page 3 of 4

We specified an OutBack power panel with two OutBack VFX3648 inverters and all the options. The panel includes an OutBack MX60 charge controller, the Mate system monitor, and OutBack disconnects all prewired. This UL-approved power panel supplied by Conergy Inc. simplified the installation and can accommodate up to four inverters if needed. Phil Undercuffler at Conergy and Matt Rust at OutBack were very helpful in the design of this panel, and Conergy had it built and shipped in two days!

We selected Surrette S-530 batteries because of their excellent reputation, long life, 10-year warranty, and safe design. The battery bank is made up of three strings of eight batteries, wired in series and parallel for a 48-volt system with about 80 KWH of total capacity (40 KWH usable at 50% DOD). The battery system has worked flawlessly. The batteries are installed next to the power panel in the shop on a custom rack that Gene built, and placed next to the south wall to help keep them warm in the winter.

Photovoltaics

The solar-electric array is made up of 22 Sharp 165-watt modules, wired at 48 volts to provide 3,630 rated watts and about 12 AC KWH per day. At the time, these were the largest panels we could get, and we received excellent service and design assistance from Doug Broach with Carmanah.

The modules were installed on two custom, tracking mounts that Gene built on site. Setting the charge parameters for the OutBack inverters and MX60 was simple and straightforward, given the information from James Surrette at Surrette Batteries and Matt at OutBack. The batteries and inverters have risen to meet any electrical demand that Gene has thrown at them. The ability to recharge the batteries with a strong generator and Gene’s willingness to manage his demand are keys to the success of the system.

Wind Generator

Gene selected the African Wind Power (AWP) 3.6 wind generator with its own controller and air heater dump load. This generator sits on an 80-foot (24 m) tower that Gene designed and built. The tower’s design allows him to single-handedly raise and lower the wind generator, another of his engineering feats.

Gene installed the tower and wind generator himself, with buried cables to the power room, where the three-phase wild AC output of the generator is converted to 48 volts DC. The AWP 3.6 is a robust machine that starts generating at about 9 mph (4 m/s), and is a quiet yet reliable addition to the system.

Microhydro

Gene’s golf course is small, but the greens require a lot of water, so he created a 5-acre pond. Two 240-volt pumps supply water to each green for an hour each morning in the summer, with ample power and energy from the system.

There is a 10-foot (3 m) drop on one side of the pond where Gene is installing his own microhydroelectric turbine. When the seasons change and the greens need less water, the hydro system will be employed to charge the batteries. In the fall and spring, the creek-fed pond used to run over the spillway. Now Gene will divert this water into the hydro generator for additional charging capability about four months out of the year. When the pond is full enough, the hydro plant will be able to run for 48 hours nonstop.