Renewable Energy is energy produced (or converted from) sources that are not of limited supply. The term renewable becomes fashionable, widely used mostly as an antipode to the most massively popular ways of generating energy – burning different types of fuels that are of limited supply.
First let’s have in mind when people say generating or producing energy it is not really meant that we produce the energy out of something else. We usually mean that we transform it from a kind that is not easily usable to one that is easily usable and transportable. Probably the closest to actually producing energy per se is nuclear power generation. Because the output of energy in a nuclear power plant comes as a result of reducing the mass of the used nuclear fuel in a nuclear reaction, so in effect we may truly say “we generate energy out of mass – something that is not energy”. But then, still if you have in mind Einstein’s discovery – the equivalency of mass and energy – we are not generating the energy – we are simply again transforming mass into its equivalent energy.
Examples:
Non-renewable energy generation:
- burning coal, oil, natural gas, to generate electricity; natural gas though not renewable is considered very clean and of quantities of supply;
- burning oil products (gasoline, diesel) to produce mechanical energy, like in cars, rail way engines,
Renewable energy generation:
- burning wood or other bio-mass; yes, though it looks lie very old fashioned, burning wood, with certain qualifications, is renewable energy since wood can be grown again relatively quickly; and here is where the certain qualifications come – burning wood or other bio-mass is considered renewable only if we are burning quantities and kinds that can be regrown as quickly as we burn them; typical examples are burning saw dust that is by product of the wood processing and furniture industries; burning of remains of agricultural plant products;
- converting solar light energy in to electricity directly by photovoltaic devices;
- converting solar light energy in to electricity by first turning it in to thermal energy – the so called solar thermal;
- converting solar energy simply in thermal and using it as such (thermal) – heating water through solar thermal panels, heating a house directly with solar – this may happen unintentionally but a house can be designed and constructed in a way that when needed solar heating is efficient;
- converting wind kinetic energy (mechanical energy of motion) into electricity by us of wind turbines;
- capturing wind kinetic energy, and without converting it in to another kind, using it for what we need – in wind mills to turn mill stones;
- using thermal energy accumulated in the ground as thermal (heating and cooling a building)
- converting thermal energy accumulated in the ground in to electricity by first heating water to steam and then using more traditional turbine to get generate electricity;
SolarMaxDirect: feel free to comment on this; there are so many examples to be given
