Energy Innovation Potpourri | Green Energy News

October 26, 2008 – Vol.13 No.32

ENERGY INNOVATION POTPOURRI.

There seems to be no end to new ideas to generate clean energy or use conventional more energy efficiently. Here are few that popped into my E-mail program in the last week or so.

--- Husqvarna, the world’s largest producer of chain saws, commercial lawn mowers, trimmers, leaf blowers and garden tractors, is now marketing the Automower(TM) Solar Hybrid. As its name implies, it cuts grass automatically without human labor, using a hybrid power source of solar energy and battery power.

No need to push it around, the mower drives itself and stays inside the boundaries of a lawn using technology similar to that used for invisible fences that keep dogs in the yard – a buried wire to transmit a radio signal, to, in this case the Automower.

Use as often as you like, the company says. Since you don’t have to push it who cares if mows every day? Mowing frequently is probably a good idea, since the Automower is unlikely to have enough power to chomp through overgrown grass. The mower has three razor-sharp blades to shave the lawn. The company says the mower can cut half an acre on one charge. It won’t run on solar power alone. The photovoltaic array just extends battery power and, of course, looks cool on top of the mower.

The 22-pound mower cuts day or night, rain or shine, says Husqvarna. I don’t know about the cutting wet grass idea.

--- Just when we thought light emitting diodes (LEDs) were to be the light source that would replace incandescent bulbs, Eden Park Illumination says its Microplasma Lighting (tm) will do the job even more efficiently – up to 95 percent efficient – better than LED’s 80 percent efficiency.

Frankly, I have no idea how this technology works (the company’s website explains) but I do know that plasma televisions emit some light. So, if a similar technology can be enhanced to emit light instead of pictures, the company may be on to something.

Eden Park calls its technology disruptive, perhaps even disruptive to the growing LED technology which the company sells as well. At the current state of development, Eden’s Microplasma technology has a luminous efficacy of 30 lumens per watt (LPW). The company expects it to reach over 100 LPW eventually. A 60 watt incandescent bulb emits about 800 lumens, so at 100 LPW an 800 lumen Microplasma light would consume about 8 watts of electricity. (Even at 30 LPW the 60 watt equivalent would need only about 27 watts of juice.)

The technology is credit card thin and could be used for flat panel lighting. The mercury-free light source has an expected lifetime of up to 50,000 hours, according to Eden Park.

--- Light rays from the sun travel 93 million miles to the Earth in pretty much a straight line (perhaps with an infinitesimal bit of gravitational bending) until they hit our atmosphere, where they start to bounce around as they reflect off of various surfaces. Even particles in the air reflect sunlight. If light didn’t reflect, the shade of a building would be pitch black.

Light, too, hits the Earth at an ever-changing angle as the earth rotates. Those who design and engineer solar electric systems try to point the system at the sun for the best average absorption of sunlight as the sun goes from horizon to horizon. Sometimes tracking devices are added to keep solar panels aimed at the sun as best as possible.

The majority of solar systems are made of flat solar panels without any kind of tracking.

Solyndra, of Fremont, California, thinks flat, essentially two dimensional, panels aren’t good enough, that a third dimension should be added. The company thinks that cylindrically shaped solar cells or modules (thus the name Solyndra, solar cylinder ) can do a better job at capturing sunlight throughout the day. Further, the company says that long tubular cells can collect light reflected from the surface that the system is mounted on: the underside of the cell captures bounced light. Spacing the cylinders apart also allows a nice air flow around each cell to keep them cool if they get hot and reduces wind resistance over the whole system. The company uses copper-indium-galium-selenide (CIGS) thin-film technology which is flexible and thus can be rolled into long tubes.

The company has announced a supply order from GeckoLogic of Germany that could be valued as much as $250 million through 2012.

--- If sunlight bounces around a little bit, wind moves around a lot. Puffy winds can come from one direction at one moment, a slightly different direction the next. Small, propeller-type, horizontal-axis turbines twist and turn rapidly to meet the wind head on. Big turbines need to be moved under power to meet the wind. Wind, too, can come up from the ground or down from the sky at an angle: hard for the turbine to make efficient use of.

Vertical axis turbines have the ability to capture wind coming from any direction without the machine having to turn to meet it. Comprehensive Precision Machining (CPM) of Boise, Idaho has developed a vertical axis wind turbine that’s not only able to take advantage of this feature but actually leans into the wind a few degrees to capture even more energy.

The company calls the turbine Blackhawk (or the AR-10 Tilt Rotor.) If the name Blackhawk sounds like a U.S. military helicopter it shouldn’t be a surprise. Like the blades on a helicopter the pitch of the three blades on CPM’s turbine is automatically adjustable without electronic controls. Pitch control allows for a low cut in speed for the turbine: light winds of 7 miles per hour.

The company has just launched Blackhawk commercially.

Links:

Automower(TM) Solar Hybrid
http://www.automower.com

Eden Park Illumination
http://www.edenpark.com

GeckoLogic
http://www.geckologic-usa.com

Solyndra
http://www.solyndra.com

Comprehensive Precision Machining
Blackhawk (or AR-10 Tilt Rotor)
http://www.cpmach.com/greenenergy.htm
http://www.cpmach.com/ar10.htm (video)