|Posted by madayerf on February 12, 2013 at 8:20 PM|
I was glad to attend the Renewable Heat Workshop in Toronto. This was the first joint effort between CANSIA (Canadian Solar Industries Association) and the CGC (Canadian GeoExchange Coalition). Considering that I have gone for training for both solar and geothermal, this workshop was right up my alley! I stayed at the Planet Traveler Hostel, which features solar thermal, pv and geothermal, in the spirit of the renewable heat workshop!
Half of the workshop focussed on a policy in the UK that is like a feed in tariff for renewable heat. In Europe they focus not only on electricity that is sourced from renewables but energy as a whole, to include electricity generation, transportation and heating. Having some experience with Ontario's FIT, it was interesting to see how the UK has done the same for heating, including having to meter and record units of heat.
The Second half of the workshop were technical presentations of how solar and geothermal have been paired to date. Some of the presentations included:
-Drake Landing Solar Community: A 52 home demonstration by NRCan near Calgary, that features solar thermal collectors on garages that feed to a central borefield and some large short term storage tanks. This heat is stored and then supplied to the homes. Initially natural gas was used to supplement the heat required, but after 5 years of operation, it now has balanced to the point where barely any natural gas is used to heat the homes. 97% of the heat for heating and domestic water are solar sourced year round!
-Atmospheric Energy Systems: Ron Tolmie, a physicist from Kanata presented the Volker Thomsen Home in Kingston that features a smart borehole alignment that allows seasonal heat storage. Heat can be sourced from the hot summer air, solar thermal collectors, water cooled pv panels, excess heat from commercial buildings, etc. This heat is injected into a central ring of boreholes. An outer ring of boreholes then collect that heat 6 months later after it has slowly travelled outwards. This would allow loop lengths to decrease significantly as the system is sized for storage capacity rather than extraction of existing earth heat.
-Earthlink - The manufacturer of Direct Exchange Heat pumps is looking to pilot a nifty combination of geothermal, solar pv and solar thermal technology. Currently, solar pv and solar thermal panels compete for roof space, and solar pv panels are typically only ~20% efficient with much of the solar energy wasted as heat. Not only this, solar pv panels get less efficient the hotter they are. Earthlink showed that they could cool solar pv panels with a DX refrigerant loop behind the panels and then that heat could be used to heat water or stored in a geothermal system. For more see the abstract in the workshop program.