Unlike fossil fuels such as oil and natural gas, renewable energy is sustainable because it is derived from inexhaustible sources such as the sun (solar), wind, biomass, water (hydro) and geothermal. Renewable energy sources are not man-made and occur naturally.
Because of their sustainability, renewable energy sources can be relied upon for producing long term, cost effective and efficient power. Also known as ‘green energy’, these enviro-friendly energy sources are generally non-polluting and cleaner to use than fossil fuels such as oil. When commonly used in systems to generate electricity, they do not emit toxic waste or produce greenhouse gases.
Many governments around the world are looking at renewable energy to reduce our dependence on oil and other polluting fossil fuels. For example, in Australia where I live, the government has committed to ensuring that twenty percent of Australia’s electricity supply comes from renewable energy sources by the year 2020. To encourage electricity users to participate in this initiative, incentives such as rebates, grants are being offered to various community groups, schools, homes and businesses to install solar power. End users are also being given the opportunity to ‘feed in’ to the electricity grid any excess power they generate.
Another aspect of the call to ‘go green’ is that electricity suppliers have the ability to offer to their customers, power which has been produced by the use of green energy such as commercial solar arrays and wind turbines or wind farms. The customer pays a slightly higher cost for their electricity but it is a way for them to reduce their dependence on fossil fuels.
Alternative Energy Sources
At the level of our current electricity generating technology, the main alternative energy sources are solar, wind, hydroelectric and hybrid systems.
Solar power is created from sunlight, in the case of electricity generation or, in the case of solar hot water systems, the heat from the sun. Solar panels are generally mounted on the roof to allow an unobstructed path for the sun’s energy. Solar hot water systems are very efficient and have been used for many years whilst solar electricity is a reasonably new technology. Solar electricity is generated by photovoltaic cells contained in the solar panel. The cells produce an electric voltage when sunlight falls on them.
Wind power uses the force of the wind to drive a wind turbine which generates electricity in the conventional way. Exactly like a common windmill, the water pump is replaced by an electric generator. Wind generators utilize a completely natural phenomenon to produce green renewable clean energy.
Hydroelectric electricity is electricity produced by the force of water flowing over and driving a water turbine or generator. Instead of wind as in a wind turbine, the flowing water rotates the turbine’s blades. Like wind turbines, the effectiveness of hydroelectric systems is dependent on the availability of a good supply of flowing water. There are micro-hydroelectric systems available which can be used in remote areas where there is a good water supply.
Hybrid power supply systems are simply a combination of the already mentioned energy sources. Usually consisting of solar panels and wind turbines, these can also integrate more conventional generating equipment such as diesel generators and battery banks. The current technology for these systems is already quite mature and well tested. Because of the flexibility offered by hybrid systems, these are relatively easy to upgrade or expand as required.
When it comes to implementing an alternative green energy system, there are many possibilities ranging from the complete professional system costing many thousands of dollars up front to the basic diy system which starts off small and can be expanded when more funds are available.
In the years to come, we will hear more and more about green energy and as the power bills continue to increase, the cost of going green will begin to look very attractive.
Copyright Colin Herbertson 2009