Solar technology is a renewable and reliable alternate to the orthodox energy sources. Solar homes are a great way to tap this energy and use it. But building of a good solar home requires lot of important considerations and Shading is one such parameter.
Solar homes are a sensible and passive technology which helps in tapping of solar energy. Shading is a normal feature which is ubiquitous in most places. However for solar homes shading has to be done in a thorough and careful way so that the efficiency of solar homes is not hampered.
The south facing walls generally require more absorption (for winter sun) than the east-west facing walls (emitting solar radiations). Therefore shading on the east west walls is beneficial for the solar homes’ efficiency. Thus for different parts of the house different shades have to be applied according to the climate of the locality.
Importance of Shading in Solar homes
Shading is important for all types of houses. For solar homes, shading can be a key factor in increasing the productivity. Inherently shades help in reducing the solar radiations providing a much needed comfort in hot climates.
- Increase the efficiency : Shading leads to an increase in efficiency of the solar homes through increasing emissivity of the lighter colored walls. They also help in preventing over heating of the darker colored south facing walls.
- Optimum absorption on south windows : Over heating of south facing walls is also not recommended. Excessive heating especially in summers can lead to discomfort for the residents of the home. Therefore shades help in keeping the comfort level of the residents to the maximum point.
- Savings in heating and cooling costs : The utility costs are saved due to solar homes. Solar homes are further facilitated via proper shades on right sites. With an effect on efficiency shades help in saving the heating and cooling cost which may have incurred otherwise.
Solar Home Shading Optimization Options
Shading is important to keep out heat and make the house ambient. It also helps the south facing windows to have lower amount of heat in summers. They can then be removed in winters for maximizing the solar power generation. For east and west facing windows which should preferably be light colored, shading is less important.
Overhangs and awnings can help keep out the summer sun. However they lead to decrease in solar gain as shadings like overhangs are not thorough enough for all climates.
Movable overhangs have maintenance problems. Awnings though helpful and durable are aesthetically poor.
Vegetation as shading is also useful as vegetation provides natural blockage to the solar homes and vegetation lessens during the winter seasons. However the growth of plants may not deescalate fast enough leading to losses in solar energy production.
Therefore dogmatically awning and appropriate glazing for windows should be preferred for solar homes though growing plants and using movable overhangs have their own benefits.
Types of Shades for Solar Homes
Various types of shades have been made available for use in solar homes. According to the place they are meant to serve and the climate of the region, the following can be used:
- Overhangs - These are the most popular and widely used shades for most of the houses. Overhangs are used external to the house and are mostly fixed. This causes them to cast the same shadow in most of the seasons. This can hamper the efficiency of the solar homes. Therefore practically they are not preferred.
- Awning – Awnings are covering on the external sides of the homes. Awnings are easily built. They are flexible to use, reliable and efficient. However awnings do require regular maintenance and their appeal aesthetically is mediocre.
- Movable shades – Movable shades are pragmatic and have numerous advantages to the more used overhangs which are fixed. These movable shades can be used to cover the parts most prone to heat and can be removed afterwards. However the shades are harder to maintain and can deteriorate rapidly as they are exposed to manual handling and environment.
- Natural shades through Vegetation growth – Vegetation growth is another way of providing shades to the solar home. As the vegetation can be controlled to grow in the hot summers and dry up in the winters, the natural shades provide a practical solution for the solar homes
However the natural vegetation can also ruin the amount of electricity being produced by the solar homes. This may be due to uncontrolled growth of vegetation on various parts of the walls.
Summing it all up ..
Shading is an important aspect of solar homes. They not only provide immunity to the increasing heat levels in the region but also help in increasing the productivity of the solar homes. Therefore at the time of building the solar homes options of shading should seriously considered for better working of the home.