Definition of Renewable Energy
Solar Energy is just a part of Renewable Energies. So for a definition of Renewable Energy:
Renewable Energy are those sources of Energy which can be replenished by nature without man doing anything about it.
Solar energy is a Renewable Energy (it would be better called ‘self-renewed’) because the sun provides this energy and using this energy by man does not diminish the resource.
The same for Wind Energy. The wind is there and putting turbines in its way does not use up the wind. It gets “renewed” by nature itself.
So the Definition of Renewable Energy is “Energy coming from Natural Sources, which are not diminished by the usage of this energy”.
One could argue that oil and natural gas are also coming from natural sources, but when we use them they actually get less, they are not replenished by nature or the process is so slow, that humankind will probably not be there when it is done.
So by the Definition of Renewable Energy these natural sources are meant:
- water (ie. tides/streaming water)
- earth (geothermal)
The Renewable Energies are on the rise, and we will need them. Though it is debated if we are running out of oil supply (“oil peak”) or not, no non-renewable energy resource we have will be lasting long enough to supply the world’s growing hunger for energy for long…perhaps not even decades.
Even Nuclear Energy, which we are told must be our future, will run out of supplies of Uranium sooner or later.
As a sidenote: I find it amusing that Nuclear Energy is nothing more than a very expensive and very dangerous successor of a machine invented some hundred years ago by James Watts: The Steam Engine. All the Nuclear Plant does is heat water to get steam. Very expensive steam, but steam nevertheless.
Definition of Renewable energy: Figures
In 2009 the number of households and businesses consuming “green” renewable energy worldwide grew to 5 Mio.
In 2008 worldwide annual investments in Renewable Energy has reached 120 billion USD, from about 30 billion USD in 2004.
In this timeframe Solar Energy (photovoltaic)capacity reached more than 16 gigawatts (GW), a 600 % increase, wind power increased 250 % to 121 GW
All in all the total capacity from Renewable Energy reached 280 GW.
In the same time Solar Heating and Biofuel capacities increased dramatically.
The gains were especially dramatic in 2008, and even the financial crisis does not seem to tank the rise of Renewable Energies…and we will need them.
The International Energy Association assumes that in 2030 we will need 40 % more energy than 2007.
China, India and the other Asian countries will have a rising hunger for energy. So I predict the less you are dependent on traded and non-renewable energy – like oil or gas – the better you will fare in the future.