Passive Solar Energy

Exploiting solar energy passively can be highly cost effective. The simplest way to use solar energy is to make the most of daylight so as to reduce the need for artificial lighting. Heat and light from the sun can also be more effectively exploited by designing and constructing buildings purposefully. Factors to consider include the location and alignment of a building on a property, the shape of the building, window sizes and building materials. Designing a building to exploit solar heat and light optimally can greatly reduce its future heating and lighting costs.

South-facing slopes are good locations in terms of the availability of solar energy. Protection from the wind is also desirable. The local relief and trees can be exploited as natural windbreaks for this purpose.

Exploiting natural heat and light

The aim is to store heat, facilitate the exploitation of natural light, and reduce heat loss. The risk of overheating during the summer must also be considered, however. Preventive measures include roof and eaves design, glass-covered conservatories that can be easily ventilated, flow-through ventilation and the use of curtains, blinds, shutters or other such movable elements.

In the wintertime, good insulation, heat-storing materials, glass-covered porches and conservatories, bearing walls, large south-facing windows and smaller north-facing windows all help to exploit solar energy passively.

Roof structures can be carefully designed to provide shade during the summertime but not block light from the sun in the winter when it is much lower in the sky. Special care should be taken to exploit natural ventilation effectively.