Whenever AC current gets converted to DC, or the engine in your car kicks into action, heat is a byproduct. Some say it's a viable source of power that's been ignored.
Have you ever felt the back of your computer or television after using it for a long time? Depending on the age of your device, it likely emanated significant warmth, called waste heat.
While a little heat from a notebook or a cell phone doesn’t seem like a maelstrom, the cumulative effect of waste heat is staggering. Back in 2008, researchers at UC Berkeley estimated that the U.S. consumes 100 quadrillion BTUs, or quads, of energy a year and that 55 to 60 of those quads get dissipated as waste heat. The Wartsila-Sulzer two-stroke diesel engine for ships is considered one of the most efficient in the world: half of the energy gets converted to waste heat.
The trick is finding a way to trap and convert the waste heat into a useable format. Currently, some innovative people are trying to figure out how this could be accomplished.
Echogen, a startup, says it can exploit a fluid called supercritical carbon dioxide (ScCO2) to convert heat into power for less than four cents per kilowatt-hour. The average retail price of electricity in the U.S. hovers above 9.5 cents (GreenTechMedia).
Two senior citizens from Washington, MO have developed a new filter for electric clothes dryers that captures the heat usually exhausted from the dryer and reroutes it into the house (see above). Jim & Sandy Atkinson decided to call the device the "Dryernet" and discovered that dryer vents longer than 10 feet, the dryer dries the clothes faster due to increased airflow.
"The original thought was to save on heat to cut expenses," said Jim Atkinson, but there are added benefits to the product that we never anticipated. "It adds much needed moisture in the winter, so you don't have to have a humidifier going, and saved our family about $20 a month on heating bills in the winter."
Other companies, like Komatsu, Alphabet Energy and Phononic Devices are devising chips that can convert heat to power directly. No mechanical compression needed. Wrapping these around components in a car or truck could provide power to run the air conditioner, which in turn would boost mileage (GreenTechMedia).
Although we typically think of wasted heat as a problem of industry and electronic devices, the energy produced naturally by human body is being considered as a potential power source.
Central Station in Stokholm is Sweden's largest rail station and the busiest in Northern Europe and now the real estate company that owns the station is putting rail passengers' body heat to good use. Heat exchangers have been installed in the station's ventilation system to transfer the excess body heat to water which is then used to create warmth in a building across the street. This method of heat capture lowers the energy costs of the office block by 25 percent.
Image Credit: Flickr - mujitra