The sun has always been, and it still is, very useful to man and other living things. Apart from providing sunshine, it helps in the growth and
development of humans, plants and animals. Today, its use is no longer limited to living things because homes and buildings are also benefiting
from solar energy.
A 2005 report on renewable energy sources revealed that
solar power is the most widely used among renewables today. The Worldwatch
Institute report entitled “Renewables 2005: The Global Status” showed that
solar photovoltaic is the fastest growing energy technology with a 60
percent yearly capacity increase from 2000 to 2004. Nearly 40 million homes heat their water using solar collectors and two million households
utilize solar lighting systems.
Around the world, solar energy is now utilized in a number of applications. In the home, it provides light, warm air and hot water. It can also be used in cooking and in the treatment of saline and brackish water.
The use of sunlight in building design dates back to the ancient times. The Greeks and Chinese were among the first to use advanced solar
architecture and urban planning strategies. Their technique, known as the passive solar architecture, was to position buildings toward the south
to enjoy enough light and warmth.
Passive solar architecture orients a structure in relation to the sun and also makes use of compact proportion, selective shading and thermal
mass. These features are aimed at creating spaces with good lighting and comfortable temperature range. Coupled with active solar equipment,
the system performance of a passive design is sure to improve.
Daylighting system is another passive application of solar energy. The goal of this system is to collect sunlight and distribute it to interior
spaces. With natural sunlight, the use of artificial lighting is reduced thereby lowering the home’s electric bills. It also has positive psychological
and physical effects.
The use of solar heating and cooling technology is now growing in popularity as well. Basically, this utilizes thermal mass or any material that
can absorb the sun’s heat during the day and release it at night. This material can either be stone, cement or water and their size and placement
are dependent on climate, daylighting and shading conditions.
For ventilation purposes, a solar or thermal chimney is an ideal option. This type of passive solar ventilation system involves a vertical shaft that
connects the interior and exterior of a building. Warm air is produced as the chimney gets warm. With the addition of glazing and thermal mass
materials, performance of this ventilation technology is sure to improve.
Domestic water can also be heated by solar hot water systems. This type of system is commonly used in homes for washing and bathing
purposes and for heating with swimming pools.
Solar cookers are also available today and are categorized into the box, panel and reflector cookers. The reflector type, invented by Wolfgang
Scheffler in 1986, is used in solar kitchens. The world’s biggest reflector system is located in Rajasthan, India and is capable of cooking up to
35,000 meals every day. Statistics in 2008 showed that more than 2,000 Scheffler cookers had been manufactured worldwide.