Take heat, be cool. Sounds like a line from a jazz standard, but it’s also a description of solar absorption cooling — a method of air conditioning that uses the power of the sun, rather than electricity, to operate.
Heating buildings through the power of the sun is nothing new, but solar-powered air conditioning seems like a contradiction in terms. In fact, it is merely harnessing the sun’s power another way: it uses water, heated by the sun, to drive the chillers in air conditioners. Not using electricity gives solar absorption cooling a huge advantage, because the electrical grid can get dangerously overloaded during heat waves as commercial and residential energy consumption soars.
Different approaches to solar absorption cooling are in use around the world, but in 2016 a team from Toronto’s Centennial College took on the challenge of building their own system. Team members were Mihail Plesca, who holds a Ph.D. in mechanical engineering (and specializes in solar energy), Centennial’s innovation program manager for energy, Hassan Haji-Esmaeili, and two student researchers, Eromosele Basil Ahunun and Harsh Pandya.
The team ran a software simulation based on the solar absorption cooling system they had designed, and found the optimal temperature for their single effect lithium chloride absorption chiller to operate at was 90° to 100° degrees Celsius.
In August 2016 the team presented their findings on their integrated solar absorption cooling system to the 2016 International Conference & Exhibition on Clean Energy at McGill University, where their results were well received.
The team continues to collect data on how well the prototype chiller performs and how accurately its components match with the simulation results the group presented in Montreal. A close match between theory and practice will make it possible to set the system up in other locations.
