Week 2: Solar energy for heating and daylighting
This week you will look at some of the methods employed to gather and use the Sun’s thermal (i.e. heat) energy. You will also look briefly at the role of the Sun’s light in reducing the need for artificial lighting in buildings.
Hello. This week we look at the use of the Sun’s energy in buildings for space heating, water heating and lighting. Only a small proportion of the Sun’s energy is intercepted by the Earth 150 million kilometres away. But it’s sufficient to keep the temperature of the planet suitable for life.
We also look at the variations and the amounts of solar energy intercepted in different seasons and regions of the globe. And we look at the design of buildings to make maximum use of solar energy for space heating and lighting passively without the need for special collectors and this building gives a very good example.
We then look at active solar collectors such as the rooftop solar water heaters that are common in many parts of the world. We go on to examine heat pumps which use electricity to raise to a useful temperature the ambience energy that’s available from the air, from the ground or from water.
Finally, we look at concentrating solar power systems or CSP for short in which the Sun’s rays are concentrated using mirrors or lenses to generate high temperature steam that’s used to power electricity generators.
By the end of the week, you will be able to:
- describe at an introductory level the basic principles underlying the availability of solar radiation and the seasonal differences in solar radiation reaching the Earth at different locations
- understand at an introductory level the basic physical principles underlying the operation of solar thermal energy systems
- describe the main differences between active and passive solar heating systems, and the basic principles of solar ‘daylighting’
- understand at an introductory level the use of solar energy to drive engines for electricity generation and the main ways to concentrate the radiation to produce high temperatures.