Active solar heating systems are one of two main ways to utilize clean and renewable solar energy to help heat your home, the other being passive solar heating systems. Both usually need additional back-up heating systems and options for the colder winter months or for cloudier days but both can still save you a lot of money and energy throughout the year.
What is active solar heating?
The active solar heating definition is that it’s any heating system that’s powered via sunlight and uses an active electrical mechanism such as fans, blowers, or pumps to transfer that heat via a liquid or air solution through your home.
The difference between active and passive solar heating systems is that passive systems don’t bother distributing the heat in any way and just rely on the natural heat flow of the sunlight to distribute its own warmth.
There are two main types of active solar heating systems:
Air circulation systems
The simpler option of the two is air circulation systems. They collect sunlight via flat darkened panels mounted on the southern roof of your home to collect sunlight. These panels are then covered with protective and transparent covers to form narrow air chambers around them. The air in these chambers heats up pretty quickly and can then be distributed throughout your home with a simple fan or blower.
Liquid circulation systems
A more complicated variant of active solar heating systems, liquid circulation systems also utilize the same flat darkened sunlight collector panels but use ethylene glycerol (anti-freeze) to transfer the collected heat into your home. It’s important to use anti-freeze instead of water as water freezes in the winter.
Once heated, the anti-freeze is pumped into and stored in an insulation tank. From there, a second pump will either 1) distribute the liquid through pipes around your home to provide heating or 2) it will guide the liquid to a furnace where it can warm up air that’s then going to be circulated around your home, effectively making an air/liquid circulation system.
There are other variations within these two main categories in how solar heat is distributed and they are explained pretty well on the site of the U.S. Energy Department. However, these are the two main definitions and distinctions you’d want to start with.
Active solar heating advantages and disadvantages
The main advantages of using solar power to warm up your home can be summed up like this:
- Solar energy is renewable and efficient – you don’t need to pay for it and you can save a lot on your electricity bills with it.
- It’s eco-friendly – solar energy doesn’t need to be mined and processed, it doesn’t produce any harmful byproducts, and it’s not a finite resource that we’ll eventually run out of.
- Solar energy installations such as active solar heating systems have very low maintenance costs compared to other heating systems.
Of course, these systems are not without their drawbacks too:
- Solar energy is weather dependant – this means that it’s not always reliable and you’ll need a backup system in place to pick up the slack when there’s not enough sunlight to power up the system.
- Solar energy storage is inefficient – different systems can store solar power for different amounts of time but not for nearly as long as other heating systems. This means that you’ll need to use the solar power almost as soon as you’ve collected it.
- Solar heating systems require a fair bit of space and have considerable installation costs.