|
|
| |  | |
| Off the grid (December 2005) |
|
|
|
|
|
|
No power, no problem. Today’s technologies keep you independent
By Dale McDonald
When Allen and Diane Hooper found their dream cabin in the mountains of southwestern Colorado, the surrounding alpine beauty was undeniable. Snow-covered peaks. Golden aspen leaves. Herds of elk and deer. More stars than they had ever seen in their lives.
Beauty, however, was a little bit more difficult to apply to the cabin. “It was a funky, 70s-era contemporary with cheap painted plywood siding that looked sadly out of place in its spectacular setting,” says Diane. “The inside was even worse. It was half-finished and poorly maintained, with bare chipboard ceilings and holes in the walls. Our teenage daughters thought we were crazy to even consider it.”
There was another small problem for the girls. The nearest power lines were miles away, and that’s where they’d stay. The Hooper’s cabin was off the power grid. The only electricity at the site came from a small generator with an electrical cable that culminated in a single female adapter. With a total renovation planned, it didn’t seem like enough.
That first summer, the Hoopers hauled remodeling supplies from their home in Acworth, Ga., and went to work, relying on the generator. The next year, Diane suggested they look into solar power as an alternative.
“It was a little surprising,” Allen says, “there were multiple manufacturers for all the components. There was competition, and prices were pretty reasonable. In 1997, we spent about $7,000 to install four 60-watt photovoltaic (solar conversion) panels with a 2,400-watt AC inverter and a controller. Twelve 6-volt, deep-cycle batteries serve as storage. With a 5-kilowatt generator as backup, we put in seven receptacles and two light switches. The system supplies a 120-amp breaker and it’s been all we have ever needed.”
Using electricity from the sun, the Hoopers replaced the siding, deck, porch, and windows. For storage, they built a garage nearly as large as the cabin. They also replaced the interior paneling, flooring, and ceilings, and built a loft. Once the cabin was finished, Allen and Diane learned how to live within their new means. Essentially they have all the power they need, but none to waste.
Allen notes there are several keys to living off the grid. First, convert as many appliances as possible to propane. Be sure to avoid electric refrigerators, water heaters, and stoves. Also, use power strips with on/off switches at the outlets so items like television sets can be turned off. Otherwise, they are in “instant-on” mode and are always pulling power. That applies to any item with a remote control.
Allen says another essential ingredient is a usage meter. A good meter will tell you how much electricity is being used, how much is being generated by the solar panels, and how much is left in storage. The meter, he says, is the best tool for learning how the system works, and when it might need a boost. Without it, you’re just guessing.
However, he says, most people are curious about how this modern technology has affected their family’s lifestyle. Over time we have developed a daily routine,” he says. “In the morning we turn on the generator and fill the water tank, and at the same time we use any power-hungry appliances like a hair dryer. That takes 15 or 20 minutes and serves two purposes. It keeps the batteries charged, and also serves as a generator check so that we know it’s ready to go as back-up power if we need it.
“The other thing is that you have to have a strategy for power use. You need a Plan A and Plan B for everything. For example, for overall power generation, especially for lighting, power tools, and telephone, Plan A is the solar system and Plan B is the generator. But for the well pump and power-hungry appliances like the hair dryer, Plan A is the generator, and Plan B is the solar system.”
It’s also advisable to invest in a decent inventory of spare parts. If you are off the power grid, you tend to be in a remote place and getting that part you need can be more than an irritation. It can really hurt.
“One time we had company coming,” Allen says, “and the generator broke down. With company, you have to have water, and I ended up having a guy from Grand Junction deliver the part. It cost $786. Now I have a stash of parts, believe me. But that was just a lesson. We are tremendously happy living off the grid at our cabin. We have everything we need, and there is no electric bill. Ever.”
Full-size house
While the Hoopers outfitted a cabin with solar power, the technology is by no means limited to smaller spaces and lesser power requirements. Otto Van Geet, a senior engineer at the National Renewable Energy Laboratory in Golden, Colo., designed and built a state-of-the-art solar home in the mountains near Idaho Springs—all 3,000 square feet of it. Total cost for energy is $200 per year, and that comes from purchasing propane for cooking, operating the clothes dryer, and providing backup power for heating the house, and for hot water. That is no small feat. At an altitude of 9,300 feet, it’s like living in upper Minnesota where heat requirements are huge. Like the Hoopers, Van Geet has developed some simple rules for living the solar life.
“First, get energy-efficient appliances,” he says. “Refrigerator, lights, furnace, everything. Investments in efficiency should always come first. For example, lighting should be compact fluorescent, not incandescent. “Second, invest in good windows, good insulation, and a tight building. Seal the building well before you do anything else. Third, invest in passive solar design features across the board. That means a south-facing orientation, well-insulated walls and roof, high solar-heat-gain-coefficient windows, the proper glass-to-floor-area ratio, an insulated slab, limited window space on the north, east, and west sides, and overhangs that block the sun during the summer heat.
Not yet mainstream
Great broadband connections are the exception, rather than the rule, for rural America. Many experts compare the situation today with the 1930s, when the nation made a great push to string electric wire over the last mile to reach the most remote rural resident. When it comes to Internet access, today’s homesteaders may not need to wait for copper wire nor fiber-optic cable to reach that last mile. Wireless broadband may be the system of the future for rural residents.
“Fourth, invest in a solar hot-water system for domestic use. A good rule of thumb is one panel per full-time occupant. They should be sloped at the latitude of the house plus 15 degrees. For Denver, which is at 40 degrees latitude, that would be a slope of 55 degrees.
“Fifth, once you’ve done rules one through four, invest in photovoltaic and other renewable energy sources like wind generators. Once you’ve done that, you are set to live off the grid with very little trouble. All these systems are high quality and they last a long time. For example, photovoltaic panels come with a 20-year warranty and require no maintenance at all. These solar-energy technologies are ready to be put to use.”
Here are the basics of Van Geet’s system:
The photovoltaic array generates 1,200 watts of electricity. Storage is the equivalent of about 48 car-sized batteries, and can hold about three days of the family’s power needs. Most loads are fed through an inverter, which takes the DC current and converts it to AC. Van Geet’s refrigerator, however, is a super-efficient DC unit because refrigerators represent the biggest power load in a house.
The backup generator is a 7.5 kilowatt unit, and rarely runs more than a few times each year. It would take many consecutive days of clouds to kick it on, and a run of cloudy days in Colorado is a rarity.
The hot-water system consists of four 4x8-foot panels. The sun heats propylene glycol, which is pushed through the system by a small DC pump that, in turn, heats the water in the indoor storage tanks. There are two 80-gallon storage tanks with heat exchangers.
The wind generator is small at 400 watts, but it still has its place. Van Geet says it helps provide energy on cloudy days when the wind has a tendency to blow.
Finally, Van Geet totally embraced the concepts of passive solar design. From roof to slab, the house is designed to gain heat in winter and repel it in summer. “At my house, I used concrete block for the walls because that creates thermal mass,” he says. “You want a lot of mass because it eliminates temperature swings. In effect, the walls themselves store heat at night. With really good insulation—I have five inches of foam on the exterior of the house—heating is a simple process. The sun heats the house, and the house heats the concrete block. The heat gets transferred even though the sun does not shine directly on it.”
To the uninitiated, a stroll through Van Geet’s house would be somewhat uninspiring. And the reason is that it doesn’t look any different than any other traditional house you’ve ever seen. It’s big. It’s airy and comfortable. It has TVs and stereos and computers and washers and dryers and hot-water heaters. It takes a while to realize just what’s missing, what’s so odd. Otto Van Geet’s house has everything but power lines.
|
|
|
|
