The Sun is a star that is approximately 150 million kilometers away from the Earth. The Sun is an inexhaustible source of energy, therefore, solar energy is sustainable energy. Our planet receives the energy of the Sun through radiation in the form of light and heat. This energy, together with the secondary forms of energy, such as wind energy, tidal energy, hydropower and biofuel, forms more than 99.9% of all renewable energy on Earth. Solar energy is not polluting, it is silent and we can use it as long as the Sun exists. Because of the recovered solar energy, mankind can keep using fossil sources of energy for longer. Moreover, the usage of solar energy does not produce any waste products. All in all, if we know how to use it correctly, solar energy is the best and greenest energy source available on Earth!

Passive solar energy

We can use solar energy with the help of technology, for example, with the help of solar panels. However, effective usage of solar energy is possible even without involving any complex technology. If we use the solar energy directly – we are talking about the passive solar energy usage. Passive solar energy can provide us with light and heat inside our houses. However, to be able to use this energy efficiently, we have to take some factors into account as early as during the design phase of the house construction.

Glass and passive solar energy

Glass is the most important element in efficient passive solar energy usage. Windows are obviously essential for letting the sunlight to come into the house. As long as it’s light outside, there is no need in using electrical light sources. Glass windows also ensure that heat can enter the house. This heat transmission works both ways: they transmit the heat from the inside to the outside, but also from the outside to the inside. The last process happens due to the transparency of the windows, allowing sunlight to come in.

To make optimum use of the sun, one has to install relatively more windows on the southern side of the house and less windows on the northern side of the house. The reason for that is very simple – there is much more sunshine on the southern side than on the northern side. Therefore, while northern and southern windows allow the same amount of heat to pass from the inside to the outside, the heat flow from the outside to the inside is greater on the southern side.

A so-called sun-room can also generate a lot of energy profit. In the closed off sun-room under direct sunlight the temperature quickly becomes higher than in the rest of the house. This warmth can be subsequently distributed throughout the whole house with the help of a ventilation system. It is important that a sun-room should necessarily be closed. In the case of a sun-room attached to a living-room, the heat loss (especially in winter) can exceed the heat gain.

Sun protection

Many large windows on the southern side of a house provide the necessary heat in the winter. But in the summer months this heat is actually not desirable. Sun protection is essential for prevention of the uncomfortable heat in the house during the summer. It is more logical to have such sun protection outside of the house, since in this case the heat actually stays outside. Sun protection can ensure that the high sun is stopped in the summer, while the low winter sun shines under the blinds and thus enters the house.