Area residents consider solar power
Monday, April 29, 2013 3:29 AM
"You've got to put your panel where the sun is," presenter Bob Dahse told a group of local residents investigating solar energy. "It's especially important to get good sunshine in the middle of the day."
Brian Lavelle holds a “solar pathfinder” which is used to discover if a location gets enough sunlight to produce adequate energy.
According to Dahse and co-presenter Larisa Walk, if you can do that, just about anything is possible.
Dahse and Walk of rural Winona have generated their own solar electricity for approximately 30 years. On Saturday, April 13, they gave a free "solar workshop" at the home of Brian and Ruth Lavelle in Houston County's Black Hammer Township. The session was actually a follow-up to an initial meeting held last winter at the Houston Nature Center.
Solar panels produce direct current, with a typical installation combining the output of a number of panels, which are in turn made up of individual cells. The cells are actually diodes, Dahse said. The power is routed to a charge controller, which sends it on to a battery bank. Once that is charged up, the system can be put to work. Power inverters can change the output coming from the batteries to alternating current.
"Personally, I'm planning to build a ground-mounted 3 kW system," Brian explained beforehand. "It will be a battery stored stand-alone system. We'll run small loads on our closed system; even as we continue to maintain our Tri-County Electric account. The ultimate goal here is to build to a big enough size to cut the ties with Tri County."
For those who want to live off-grid, energy efficient 12-volt appliances are available for the camper/trucker marketplace, Lavelle noted. That's a simple way for 12-volt users to find just about anything they need. If you feel the need for AC power, inverters will convert electricity from the DC battery, but not without a loss of energy.
Dahse advocated mounting solar panels on ground racks, since maintaining roof mounted equipment is often a challenge. Users need to clear snow and collected leaves from their panels, since that severely limits power production. Surprisingly, photovoltaic cells produce power "quite well" on cloudy days, he added.
"Right now solar panels are more affordable than they've ever been," Lavelle said.
Dahse recommended buying from established photovoltaic (PV) suppliers, many of whom offer 30-year warranties on single and multi-crystal PV panels.
"There are people I know that have panels that were installed in the '80s that are still running fine," he said.
With over 200 suppliers making solar panels, there are a huge number to choose from. Dahse said one way of sorting through all the offerings is to look for manufacturers who have been in the business for a number of years.
"It makes sense to buy from a company that's been around for a while," he stated. "The tried and true stuff is so cheap right now; it really doesn't make sense to experiment a lot."
"Machinists used to say that the lathe was the only thing that can re-make itself . . . Now we have PV manufacturers using their own panels to power up their factories."
Walk said that with an unlimited bank account, a large enough PV system can be designed to power just about anything. For practical purposes, however, solar users should take the time to decide how much power they really need.
"I usually tell people to do an 'electrical Sabbath,'" she said. "Pick a day, a week, or better yet, a month. Unplug everything, shut off the breakers to the house, and re-evaluate your life. What is it I really need? Do I really need all this stuff? Or, do I really just need that light in the kitchen and to be able to cook? Do I need that big of a TV? Step back and evaluate everything, saying, 'These are the things I really want power for."
You may need to shed that electric dryer and the old freezer that runs all the time, Lavelle added.
Dahse added, "We had a 12-inch black and white TV in the old days that used twice as much power (50 watts) as our 24-inch LED television does now."
Walk agreed, "Sometimes it makes sense to replace something like a television rather than power it with solar. Look over the appliances that are on the market now. Some are much more efficient."
Once a person knows what their needs are, a system can be designed around them. That's when the question of siting crops up. As Dahse said at the beginning of his talk, getting unobstructed sunlight is the key. Another consideration is locating where it's easy to keep the panels clean and, in certain installations, make summer/winter changes to the angle of the array. Finally, make sure your site is acceptable from an aesthetic viewpoint.
"You don't want to be looking into the backs of ground mounted solar panels when you look out your front window..." he said. "But your installation doesn't have to be something that's ugly or obtrusive."
Dahse produced a small tool called a "solar pathfinder" that can quickly evaluate the amount of solar radiation that a given site will provide. The unit contains a compass to align its north-south axis. After leveling, a user peers at a grid work that shows the sun angles at different times of year. The simple look has another ingenious aspect. The glass dome that covers it reflects obstructions such as nearby trees or hillsides over the grid, making it easy to determine exactly how many hours of sunlight are available, and the path of the sun through the sky over the site.
"I'll help anyone in my neighborhood run a pathfinder," Lavelle said. "We're not doing this to make money. I may not be able to do too much to help others, but at least I can lend some moral support."
As far as solar power, "It's not so much of a money saving thing as it is a way to protect the environment," he added. "I want to live with a small footprint and when you look at all the schemes and dreams, photovoltaic has the best amount of energy returned for energy invested."
Lavelle continued, "You may need to somewhat dial down your living in terms of electrical use to accommodate it, but it's as cheap as it's ever been... If you think you're going to live for 15 to 20 years, you're never going to buy into cheaper power."
Dahse and Walk are offering the workshops free of charge with no other motivation than helping others find out how they can make a difference, Lavelle stated.
"The biggest motivation for me is being threatened by all the sand mining pipe dreams that we have going on," he added. "I fully understand that we're not going to drill our way out of our energy problems. And if you don't want to have a sand mine right next to you, this is what you need to do."
"Japan is pushing for more solar power to eliminate their reliance on nuclear power plants," Dahse said. "Germany has been making a major effort as well... One day, last year, a third of the country was working on solar power. That's taking into account that Germany is a heavily industrialized country."