UOIT: Thermal Energy Storage
UOIT System Diagram
Recently we ran across a short article that describes at a high level a project the University of Ontario Institute of Technology has to use geothermal resources for heating and cooling.
The system consists of three hundred and eighty-four holes, each 213 metres (700 feet) deep, will provide the basis for a highly efficient and environmentally friendly heating and cooling system, capable of regulating the temperature of university’s new buildings. A glycol solution, encased in polyethylene tubing, circulates through an interconnected, underground network. During the winter, fluid circulating through tubing extended into the wells collects heat from the earth and carries it into the buildings. In summer, the system will reverse to pull heat from the building and place it in the ground.
These are actually fairly common. They make sense whenever you have fairly inexpensive electricity, or where your electricity comes from non-carbon sources. They also work very well with distributed water-source heat pumps (I’ve designed a few for schools).
Basically, such systems pump heat around rather than generating heat (though they do that too). As it takes much less energy to move heat than it does to generate it, your efficiency goes up. If there are spaces that need heat and other spaces that need cooling, then you’re effectively pumping heat from one of those spaces to the other. If there’s heat left over, it’s pumped down into the ground. If there’s need for more heat, it’s pumped up from the ground. Because the ground contains such a large amount of thermal mass, with enough wells you have an almost endless supply of mass to transfer heat to and from.
Of course, it’s important to seperate this from the type of geothermal that actually pulls heat from the earth’s core. It’s unfortunate that both systems use the same name.
Too true. But, I have to wonder with that many holes if there is some sort of novel heat storage research they may be able to undertake that others can’t due to lack of infrastructure and funding. 384 holes in that sort of area makes an interesting experiment field.