Hybrid Thermo-Electric Solar
 Collector Technology

This technology is virtually identical to "Thermo-electric-solar" except that collection capacity is slightly enlarged and the surplus heat is used for DHW (domestic hot water) and/or space heating. Some space heating requirement and DHW requirement can possibly be met by waste heat from the heat-electric conversion as well. To understand more about basic thermal-electric solar visit this page.

The element of this technology that is hybrid is the energy storage. Most likely a standard thermo-electric system will have a large insulated holding tank with hot oil in it. This tank will likely be at a temperature between 170 C and 200 C. Heat can be drawn from this reservoir by simply circulating water through a coiled pipe placed within the tank. By circulating water with a pump through this coil called a, "heat exchanger", water can easily be heated to the 60 C point necessary for DHW. Likewise, if a baseboard or floor heating water system is installed in a house, water can be pumped through an additional heat exchange to bring the space heating water temperature to 95 C. These uses will take heat away from the reserve for electric generation, but makes for a very nicely integrated hybrid system.

Waste heat from the electricity generation component may also be used for some DHW or space heating. If space heating is used or even if DHW is used where the DHW water holding tank is nearly depleted frequently, The heat generated on the cool side of the electricity generation system can be used to bring the space heating medium or cold water part way to operation temperature. Using waste energy from one process to meet a different energy need is referred to as cogeneration. Cogeneration can go a long way toward making a system much more cost effective to operation and build.

It works like this. The cold side of the engine used to generate electricity needs to be cooled to keep the energy generation efficient. So either the cold side of a stirling engine, or the cold side of a TEG device needs to have heat taken away and dispersed to the air. This might take the form of a heat sink in which cool water is circulated. That water is cooled by a radiator with a fan. The cogeneration approach would be to provide an additional cooling option that would bring the water in a space heating boiler from room temp to say 60% of its operation temperature. The is needed whenever the boiler has not been in operation for an hour or more. This initial heating phase uses a lot of energy, so the cogeneration is very effective at reducing the overall energy need for space heating.

Another example of cogeneration might be to coil PEX tubing or copper tubing in or under sidewalks and driveways on shaded sides of buildings. Assuming you are in a climate where it snows or freezes, waste heat from your electricity generation can heat these large areas and melt snow. Swimming pool heating is another possible use for cogeneration.

The conclusion is this. If you have a thermal-electric solar system you have two possible sources of heat for other uses. Those heat sources are the hot storage tank and the cool side of your electrical generation engine. The heat tank has high temp heat but using it costs you electrical capacity. The cool side of your engine has lower temp heat, but lots of it and it costs you nothing in terms of electrical capacity. The more uses you can come up with for the lower temp heat, the higher overall efficiency your system will have.