Turning heat into electricity ...
So, the experimenting began in earnest about July 1. The big project now concerns converting, or harvesting, excess heat produced from solar heated water into electricity.
Most of the experimentation takes place in the Flow and Heat Lab, located in Old Chem, where the experiments can (hopefully) be performed on a smaller but still accurate scale.
Solar-heated water is stored in an insulated tank that holds several hundred gallons of water. That water is used for typical usages as well as for the modified air-conditioning system. But should weather conditions not necessitate air conditioning, the water tank will hold excess heat. Eventually that heat will dissipate into the environment, which essentially amounts to wasted energy and a wasted opportunity.
University faculty members Professor Anton Harfmann and Dr. Michael Kazmierczak are working with students Todd Kolloff and Adam Saltzman to develop the technology and measure efficiency and feasibility. Here is an illustration of the basic equipment and procedure involved:
Here is a photo of the apparatus attached to a hot water source in the lab:
Here is a photo of the equipment deconstructed:
Here, Todd is pointing to thermoelectric devices that are responsible for actually converting the heat into electricity. More on that in a moment ...
When the experiments are running, the thermoelectric devices are sandwiched between the heat conducting panel and the cooling fins.
The devices are attached to a conductor that will be attached to the heat source, in this case the water tank. This temperature here is naturally maintained at a releatively consistent 90 degrees Celsius (about 190 to 200 degrees Fahrenheit).
The black piece is a fin that is intended to wick excess heat away from the backside of the devices. The fins act like a radiator. It is essential for the temperature at this part of the apparatus to remain ambient -- the lower the better, and in the neighborhood of 10 to 15 degrees Celsius (50 to 60 degrees Fahrenheit) is acceptable.
In order for electrons to move through the devices and generate electricity, the hot side must stay hot, while the cool side must stay cool.
Here are other views of the thermoelectric devices. The devices consist of multiple kinds of metal, all conductors, that will route generated electricity through the center teeth and out through the wiring into storage or usage, or in the case of this experimentation, into a measuring device.
The main challenge at this stage of the game is maintaining the temperatures required to generate electricity.
The easiest way to accomplish this would be to use a fan to keep the ambient side cool. The problem with that is that the fan will use electricity. Depending on how much energy is used by the fan, the entire process may not be worthwhile, for example if the fan uses more electricity than is generated.
So instead of using a fan, the first step for the team is to find another way to wick heat through and off the apparatus without raising the ambient-temperature side above desirable levels.
The team tries to create a chimney that will facilitate the movement of excess heat up and away from the fins as quickly as possible and without using electricity.
We'll check back with the next post to evaluate progress.
