There are many types of renewable energy sources. Most of these sources depend on sunlight, in one or the other way. These sources are solar, wind, hydroelectric, biomass, hydrogen and fuel cells, geothermal power etc.
Solar energy is the most commonly used renewable energy source. It is a free source of energy which is sustainable and can never be exhausted. It does not create any kind of pollution; no gas is emitted while converting it to electricity.
What is solar energy?
It is the direct conversion of sunlight through photovoltaic cells to produce electricity and heat. This type of energy can be used as electricity to light up residences, offices and other business spaces. This is also used for heating homes, pools and other closed spaces.
The solar panels convert approximately 15% to 40% of the sun’s energy into electricity depending on the complexity of the photovoltaic cells. Technology to produce solar energy can be active or passive depending on how it is captured, converted and distributed. Passive solar energy is when the structure itself uses sunlight to achieve desired results without using it as electricity or fuel. Active solar energy is when technology is used to convert the natural source into desired electricity or heat.
In the year 2000 United Nations Development Program (UNDP) did a world energy assessment and found that 1575 – 49837 Exajoules (EJ) of energy can be produced through sunlight annually. In the year 2011 the International Energy Agency said that development of affordable, inexhaustible and clear energy technologies will have long term benefits. This will increase any countries energy security and enhance their sustainability, reduce pollution and in return reduce global warming and the price of fossil fuels.
Most common use of solar energy is in producing electricity and heat. Solar water heaters are commonly used in area where the average temperatures are below 40-degree Celsius. 60 – 70 % of the domestic hot water can be provided by this solar water heater. China is the world’s highest user of solar energy. Israel and Cyprus are leaders in per capita use of solar water heaters.
In USA, Canada and Australia the main use of this energy is to heat pool water. Remote areas benefit by getting cheap electricity through solar power as transmission line installation and maintenance costs are very high and power plants are very far off. Solar panels are being installed on lamp posts for standalone street lighting and traffic lights. Large buildings and residences are also using solar power for electricity and heating. By the year 2050 solar power will become the world’s largest source of electricity at about 27%.
In 2016 solar power generated was only 1.3% of the global power production. According to CNBC approximately 1.3 million homes in America have installed rooftop solar panels and centralized solar farms contributing to 40 Gigawatts of power. Worldwide 75 Gigawatts energy is produced through these. Germany and the Scandinavian countries are also major users of solar power.
Cost of solar energy comes out to be $7 to $9 per watt. Many government and non-government agencies give incentives and subsidies for residential solar installation of up to 50% of the total installation cost.
There are three main reasons to install household solar panel systems at homes. It saves cost, reduces carbon footprints and you do not have to depend on power companies. When planning for residential solar system, few points have to be considered:
- Estimate your energy use.
- Plan your budget.
- Improve your efficiency of electricity usage by using power saving devices.
- Assess your solar energy potential. Many devices and tools are there to help assess your home’s solar energy requirement. A technical person can accurately assess and then suggest you the best option and will also provide you with an estimate.
There are three main types of residential solar installation panels:
- Thin film
Majority of household solar panels are made of crystalline silicon.
Monocrystalline are the most developed but expensive panels. These are the most efficient ones, converting 22% of the sunlight to energy. These do not occupy much space and will give faster returns to your investment as they have life expectancy of 25 years. They are also better, performance wise, in cloudy weather. Only disadvantage is that these are expensive and are also sensitive to circuit breakers.
Multicrystalline are different from monocrystalline as they are made from multiple pieces of silicon melted together which makes them less pure. This process makes them less efficient and they convert only 16% of sunlight into energy. These are less expensive as there is less of waste while installing. However, these take up more space to install.
Thin film solar panels are also known as thin film solar photo voltaic cells. These are much less efficient than crystalline ones. These are cheap in comparison to crystalline panels. If you have large space then these are most advantageous. These are easy to make so mass production is possible. Fluctuation in weather does not affect them. Disadvantage is that these are less efficient. They can only convert 15%. These require lots of space, so if you have space constraint then these are not suitable for you. Their life expectancy is less than 25 years.
There are certain advantages and disadvantages of using solar energy:
- It’s a renewable source of energy
- It reduces your electricity bills
- One source can be used to generate both electricity and heat
- Maintenance cost is low as panels have long life span i.e. 25 years
- Technology will keep on improving as development is a continuing process.
- Pollution problem is taken care of.
- There is minimal maintenance and running cost.
- Cost of buying the solar system installation is high
- It is dependent on weather conditions as its efficiency drops in cloudy weather.
- Storage of this type of energy is expensive.
- Large open space is required for its installation.
- Technology development is associated with pollution.