What is Solar Energy

This energy drives the climate and weather and supports virtually all life on Earth. Advantages of solar energy are solar energy is a renewable resource and not making a noise. It can extract energy from the sun without making a peep, solar energy is non-polluting, require very little maintenance (it have no moving parts that will need to be fixed) and it last a long time. Solar powered system is also very easy to install.

Disadvantages of solar energy are the amount of sunlight that arrives at the earth's surface is not constant. It depends on location, time of day, time of year and weather conditions, because the sun doesn't deliver that much energy to any one place at any one time, a large surface area is required to collect the energy at a useful rate, solar cells/panels can be very expensive, solar power cannot be created at night.
Solar energy can be divided into several types. Figure 1 shows the type of solar energy.

Figure 1: Type of Solar Energy

Active solar energy technology system is a term which refers to the direct use of solar energy to actively convert the energy in sunlight into other form. Active solar systems include photovoltaic, thermal and thermoelectric. Photovoltaic is a generation of electricity directly from sunlight, thermal is using solar-generated heat for heating purpose and thermoelectric is using solar generated heat to produce electricity.

Passive solar energy technology system is a broad category of solar power technique and strategies for regulating a building’s indoor air and domestic water temperature, using climate, site features, architectural elements and landscape materials. The goal is typically to increase the comfort, efficiency and reliability of a building, while reducing its operating costs and dependence on other sources of energy for heating and cooling. Passive solar techniques include direct gain, indirect gain and isolated gain. Direct gain which sunlight is allowed to pass directly through windows and/or skylights into the living spaces and to warm the air and surfaces there. Indirect gain which sunlight strikes an intervening material (eg water or a solid mass behind glass) and then arrives at the living spaces indirectly, after being captured, stored and re-released by that material. Isolated gain which solar heat is passively captured and stored in isolated places or devices and then only allowed to move passively into the actual living spaces when and if desired.

Direct passive solar energy technology system is also popularly called green design, sustainable design, eco-design or design for environment. Green design is the catch-all term for a growing trend within the fields of architecture, landscape architecture and engineering, building physics, industrial design and interior design. The essential aim is to produces places, products and services in a way that reduces use of non-renewable sources, minimizes environmental impact and relates people with the natural environment. Green design is often viewed as a necessary tool for achieving sustainability.

Indirect non-fossil is a term which refers to the use of energy from renewable sources that ultimately is derived from solar energy. Indirect non-fossil energy systems include biomass, hydro, wind and OTEC. Biomass is use of carbonaceous materials as fuel, hydro is use of moving water to generate power, wind is use of moving air to generate power and OTEC (Ocean Thermal Energy Conversion) is use of temperature differential.

Indirect fossil is a term which refers to the use of energy from hydrocarbon which is based sources that ultimately is derived from solar energy. Indirect fossil energy systems include, coal, natural gas, oil.