What's the difference between passive and active solar heating?

Passive solar heating uses natural processes for heat distribution, while active solar heating uses mechanical and electrical equipment.

Passive solar heating is a method that involves the use of the sun's energy to heat a building without the need for mechanical systems. It relies on the design and orientation of the building, the materials used in construction, and the use of natural heat distribution processes. For example, a building might be designed with large, south-facing windows to maximise the amount of sunlight it receives. The heat from the sun is then absorbed and stored in the building's walls and floors, which slowly release the heat over time. This method is highly efficient and sustainable, but it requires careful planning and design to be effective.

On the other hand, active solar heating systems use mechanical and electrical equipment to capture, convert, and distribute solar energy. These systems typically involve solar collectors (such as solar panels), pumps or fans to distribute the heat, and a storage system for when the sun isn't shining. The collected heat can be used directly for heating or it can be converted into electricity for later use. While active solar heating systems can be more flexible and potentially provide more heat than passive systems, they are also more complex and can require more maintenance.

In summary, the main difference between passive and active solar heating lies in their approach to harnessing and distributing solar energy. Passive systems rely on natural processes and the design of the building, making them more sustainable but also more dependent on the building's location and design. Active systems, meanwhile, use mechanical and electrical equipment to capture and distribute solar energy, offering more flexibility but also requiring more maintenance and potentially higher costs.