Solar thermal vs. solar PV: what’s the difference?

With the City’s request to the Alberta Utilities Commission to obtain ownership of the Saamis Solar Park, we’re hearing our community compare this initiative to the Solar Thermal Concentrator that was previously located near the entrance to the Gas City Campground. In fact, the two projects use two completely different technologies for two completely different purposes. Here, we’ll shine a light on their differences.

The Solar Thermal Concentrator was a three-way partnership between the City of Medicine Hat and provincial and federal innovation agencies to test the feasibility of the technology in northern climates. The system used mirrors to concentrate sun rays and heat brine that is piped to the City’s main power plant as a replacement heat source to power the steam turbines, reducing the need to burn fossil fuels. The $13-million test site was built in 2012 and dismantled in 2020 when it was deemed uneconomical in our climate, thus satisfying the criteria of the pilot project.

A Solar PV system (which is the technology planned at the Saamis Solar Park) uses solar panels to absorb and convert sunlight into electricity right at the source site. The solar array is connected directly to a substation and distribution system where the electricity is transported throughout the city to its end destination (like your light switch in your home, for example). Unlike solar thermal, which was still in the testing/demonstration phase of development, solar PV is well commercialized and is now mainstream since it is economically viable and cost competitive today.