Should I Get a Solar Thermal System Instead of a PV System?
When you hear about installing solar, youre most likely hearing about PV (photovoltaic) solar cell panels. Theyve become standard in the industry.
PV solar cell panels were developed in the 1950s at Bell Labs to power electronic equipment. They picked up development speed through funding during the space program.
An older form of solar technology called solar thermal has been around since 1896. These two technologies are fascinating and have each moved solar technology forward in their own right. But when it comes to installing solar on your home, does solar thermal make sense?
Heres a breakdown of the differences between the solar thermal versus PV and which makes more sense for homeowners.
Solar Thermal Generates Heat to Warm Water
The primary use of a solar thermal system is to provide hot water through the use of solar technology.
Similar to a PV solar system, solar thermal systems requires collectors or panels on the rooftop. They absorb solar energy just as PV systems but differ in what happens from there.
Solar thermal systems have a pump circulating solar fluid (water, saline or other fluids) through the collectors and deliver heat to a water storage tank.
When homeowners need hot water, the solar-heated water takes precedence and either eliminates or reduces the energy needed by the boiler to heat water. This is how solar thermal reduces energy bills, as generating heat for water consumes a lot of energy.
Differences Between Solar thermal and PV Solar Panels
- Solar thermal uses the suns energy to generate thermal energy which is used to heat water or other fluids
- Photovoltaic (PV) systems, generate electricity rather than heat
Solar thermal is currently used more often on large-scale applications where lots of hot water is needed, like a laundromat or a college dorm. It also requires the use of large amounts of water, more equipment including moving parts like pumps and solenoid valves, has a more complex installation process and is more expensive than PV.
Why Homeowners Are More Likely Better Off With PV
Instead of two separate solar arrays competing for the same optimal south-facing roof space, installing solar PV panels and pairing them with an electric water heater is more cost-effective. This will also be more efficient both spatially on the roof and in terms of overall energy usage.
With all the extra moving parts of solar thermal systems, theres a lot more that can go wrong when installing or maintaining the system over time. The cost of PV solar panels has reduced to far less than solar thermal and theres practically no maintenance for PV.
While there are integrated solar thermal and PV systems being developed, theyre still essentially more complex than necessary. PV prices are more reasonable now, making it less expensive and less cumbersome to heat water with electricity.
In the early days of solar, one advantage solar thermal had over PV was that it allowed energy storage for intermittent power. With net metering available to most solar customers and battery storage becoming more available, its easier to store electricity collected through PV panels and use it later.
For the average homeowner looking to minimize energy costs without adding any extra projects to their plate, PV comes through as the more straightforward and less expensive option.
If youre looking into solar, heres a great post on how to conduct due diligence on your solar project. Going into any project with a good understanding of the process will ensure the process goes as smoothly as possible and that you get exactly what you need.
Still, have questions about solar PV versus solar thermal? Contact our energy advisors team or call 888-454-9979.