From the May 2011 Bright-Minded Home column in Maine Home + Design:
Maine Huts and Trails’ three off-the-grid wilderness lodges in Western Maine provide year-round accommodations and meals to hikers and skiers by using a combination of solar, hydro, and wood-generated energy to power the radiant floor heating, lights, water pumps, refrigeration, and fans for the kitchen and composting toilet.
How is power generated at each hut?
The Poplar Stream Falls Hut has a wood-fired boiler for heat and hot water, a 2.7 kWh solar array tied to 24-volt battery storage, and a 5 kWh low-head hydro also linked to the batteries. As long as there’s water, the hydro can produce up to 120 kWhs a day, while the solar produces a quarter of that due to size and dependence on sun. The Flagstaff Lake Hut and Grand Falls Hut also have wood boilers, and 5.2 kWh and 5.9 kWh solar systems, respectively, tied to 48-volt battery storage. Both average 25 kWh per sunny day. All huts use propane generators for back up, but if there’s sun and water the generators can go days without use.
How would you compare your electricity producing systems, and what’s next?
Hydro is the hare, solar is the tortoise. While the low-head hydro produces a quicker pay back (assuming a reliable water source), there are fewer variables and maintenance issues with a solar array. We plan to build another hut in a year or so using the systems above, plus a solar thermal system for domestic hot water.
See mainehuts.org for more information, and share your thoughts here.