What Is Solar Energy?
Solar energy is the harnessing of light and heat energy from the sun to provide power that we can use in our everyday lives, in forms such as heating, lighting and power for televisions, refrigerators, lights and electronic devices.
In one day, the sun sends to the earth more energy than the entire world’s population could consume in 27 years! Even better, solar energy generates no CO2 so does not contribute to global warming and climate change. In operation, solar energy is silent and clean, emits no pollutants or waste, and requires no fuel or ongoing consumables.
How is Solar Energy Environmentally Friendly?
Solar energy is a renewable energy that does not burn fossil fuels. Better still, solar energy generates no CO2 so does not contribute to global warming or climate change. In operation, solar energy is silent and clean, emits no pollutants or waste, and requires no fuel or ongoing consumables.
Is Solar Energy Really Free?
After the initial cost of buying and (if necessary) installing your equipment, yes, solar power is free and without ongoing costs. With no moving parts, solar systems should last many years and not require any maintenance, and they use no consumables.
What Types of Solar energy are there?
Technically speaking, most forms of energy on earth derived originally from the sun, even fossil fuels that are the products of photosynthesis. However, in this paper, we discuss solar power in the form of using sunlight directly to provide power and heat.
There are three common forms of solar energy:
1) Passive Solar
Passive solar is the intelligent use of insulation, window placement, thermal mass and seasonal variations to reduce the costs of heating, cooling and lighting buildings.
2) Thermal Solar
Thermal solar collects heat radiated from the sun and uses it to provide room heating, hot water for domestic use and swimming pools, heat for industrial processes, etc.
3) Photovoltaic or PV
Derived from “photo”, meaning light, and “voltaic”, meaning electric, photovoltaic solar converts sunlight directly into electricity. This electricity can then be used to charge electrical devices or DC storage batteries (in stand-alone PV systems), or inverted to AC and used in homes or fed into the mains grid (utility interactive PV systems).
The remainder of this paper focuses on photovoltaic solar.
How Does Photovoltaic Solar Work?
Photovoltaic solar panels convert sunlight directly into electricity. A photovoltaic solar cell is a solid-state device similar to a large transistor. When light photons strike the cell, they dislodge electrons, which create an electrical field. The accumulated effect of millions of these interactions is to generate electricity. By linking a number of solar cells together into a panel, a sizeable flow of electricity can be generated and harnessed for use in a flexible range of applications.
Important point: Photovoltaic systems produce electricity and do not heat water (thermal solar systems heat water). You can of course use the output electricity from a PV system to heat water should you wish.
How Can I Use Solar Energy In My Life?
There are many uses of solar energy, from powering portable electronic devices and lighting, to powering boats and caravans, to powering utility power stations producing multi-megawatts of electricity.
This section deals with the use of PV solar for personal use. PV solar produces electricity that can power any device that uses electricity. PV solar systems produce direct current (DC), which can run electrical equipment and charge batteries. Typical DC uses include lighting, car, boat or caravan battery charging, and charging portable devices such as portable fridges, pumps, mobile and satellite phones, laptops, PDAs, mp3 players, games consoles, GPS units, etc.
Using an inverter, the DC current from a PV solar system can be concerted into alternating current (AC) to power mains-operated devices such as portable televisions, larger music systems and air conditioning units.
Using Solar Power in Cloudy and Cold Weather
Photovoltaic panels actually operate more efficiently at colder temperatures. They also work in surprisingly poor light conditions, such as in overcast and cloudy conditions, although they produce less electricity in such cases. In mildly overcast conditions, solar panels might produce half the electricity they would in fully sunny conditions. On a dark, overcast day, they might product just 5-10% of their peak output. Solar technology is continuing to improve, and modern solar panels can operate progressively better in non-optimal light conditions.
Storing solar energy in a batter is one way to provide a reliable source of solar power night or day, rain or shine. Photovoltaic/battery systems are in use all over the world to power lights, telephones, refrigerators, appliances, communications equipment and even power tools.
Using Solar Power in Northern Climates
Solar panels absorb sunlight and can be used throughout the world. As you move away from the equator, you will have fewer hours of overhead sunlight and a reduced amount of generated electricity.
How Long Do Solar Systems Last?
With no moving parts and requiring little maintenance, a properly cared for solar panel should last at least 10 years, maybe 25. Proper care involves securing the panel so that it doesn’t flab about and ensuring you don’t scuff the surface. Most panels are designed to sit outside under rain (and of course sun!), although they shouldn’t be submerged in water for long periods of time. If used permanently outside, occasional wiping down will increase longevity and operational performance of your solar panels.