(Sustainable vs Renewable) energy

Lets look the "definitions" of these two phrases,
these are not an exact definitions,
different organizations and so called experts interpret and define them differently

Sustainable energy is energy obtained from a source which is not expected to deplete during the timeframe relevant to the human race.

Renewable energy is energy obtained from a source where the energy is replenished during a relatively short cycle.

Major hydro power is renewable but not sustainable.
usually major hydro power projects involved building a reservoir which would occupy a large area of land, this may change the natural environment so much that there could be long term effects such as change in rainfall etc, so whether the dam could replenish its energy for a long period of time (such as the end of humanity) is questionable. hence major hydro power is not considered renewable.
but then again this is debatable
because there are major hydro projects which have not gone bad... it all depends on how nature adopts to the change i guess...
well take the upper kotmale project.
it would change the environment but if its going change in a way that would effect rainfall which replenishes water to the reservoir for a long period of time is debatable.
so major hydro in general is not a sustainable source of energy but its renewable.

other types of renewable sources such as wind, small hydro, solar PV (solar cells) and solar thermal (solar powered hot water etc), geo thermal energy etc are all sustainable energy types

Referer : http://www-formal.stanford.edu/jmc/progress/cohen.html

Cheaper form of Green Power

Solar energy is a well established form of renewable energy. However with the present solar cells being rather thick, the cost of solar energy systems prove to be rather expensive for anyone to invest in, and use.

This is why researchers and experts inDurham University are busy developing thin layer solar cells.

These experts are trying to develop light absorbing materials that can be used for the production of thin layered, solar photovoltaic cells. These cells are used to convert the light energy from the sun into electricity.

This is basically a four year project where numerous experiments have been tried out on different materials to find out the material that is less expensive, but sustainable enough to use in the manufacture of solar panels. Today, the thicker and silicon based cells and compounds with the rare and expensive metal indium, are used to create solar panels.

So in a bid to find cheaper and more efficient materials for efficient energy production, the Engineering and Physical Sciences Research Council(EPSRC) has funded this research. The research now consists of the development cheaper and more sustainable variants of thin-layer PV cells with the help of materials like cadmium telluride and indium diselenide.

In addition to this, the team is also working on means of manipulating the growth of these materials so that they form a continuous structure that helps in the conduction of energy that is trapped by solar panels before being used for electricity.

With this, it is expected to find an improved efficiency in the functioning of the thin layer PV cells.

The research team hopes that with the development of cheaper thin film PV cells, the cost of solar panels for the domestic market gets reduced while the usage of solar power increases. Today, only one hundredth of one percent of UK’s home energy is provided by solar energy.

With thin layer PV cells used for making solar panels that fit on roofs, homes that have surplus electricity being fed back to the National grid are powered with the necessary power. This leads to cheaper fuel bills and dependence on fossil fuels.

The main reason for this research is to find materials for generating solar energy so that solar energy is made more affordable to the common man. People will definitely buy a system that could be bought off the shelf, and provide even a fraction of their energy needs, if it was economical enough.

When considering the cost effectiveness of the system, you have to consider how many pounds have to be spent for getting a watt of power. So with cheap solar panels, you are sure to get a winning product that many people will want to buy.

And with the nano-scale resolution microscopes that have been funded for the study by the Science Research Investment Fund, it is possible for scientists to find out what limits the performance of solar cells.

Wind Energy

Windmills are used to harness the power of the wind to produce electricity. Usually windmills are erected using pre-made parts, on site. The basic fan type windmill consists of the tower, gearbox and fan.

Tower parts are usually made of galvanized steel using a roll of coiled sheet metal that is put on a de-spooling device to be fed to the production line.
The sheets are run under a straightener to remove twists and kinks and then cut to the right size and shape.
sometimes the pieces may be placed on a machine to roll and weld seams wherein its ends are passed under a crimping machine to be moved to the finishing station.

Holes are drilled in the metal parts of the finishing station at specific places, as per the windmill design.

These parts may be painted or coated before being fit into a windmill.
The gearbox of the windmill has various gears, rotors, wheels and axles found in it which are die cast and assembled by hand. These parts are placed in a weather resistant housing that is built to accommodate the gearbox parts and the attached wheel and tail assembly. The fan of the windmill is made of a metal rim that is attached with curved blades.

A hole is drilled in both ends of the rim which are connected with a small screw and clamp, to which the fan blades are attached.

The rim is then connected to a center axle, and attached with five pairs of evenly spaced spokes. The fan blades and tail of the windmill are cut from a sheet of metal and run through a machine to give them a curve.
They are then attached to the metal rim using small bolts and metal clamps so that they can be raised or lowered depending on the wind.

The site the windmill has to be placed has to be an area with a prevailing wind of at least 15 mph. the area has to be cleared of trees and other structures that block wind. Sometimes, a dirt mound or concrete base is build to raise the windmill so that it catches more wind.

When assembling the windmill, the main body parts are connected first, to be bolted on the ground and then raised vertically. Connecting rods are used to join other poles while clamps are bolted at joints for stability. Once the tower is raised, it is loosely bolted to the base wherein stay wires are strung from the ground to the tensioners and ground anchors.

When leveled, the bolts are tightened and its integrity tested.
Sometimes a ladder is built in the design for easy access and maintenance at the top. then the fan wheel, main shat and gearbox are attached where the gearbox is first clamped and bolted to the top of the tower.
Then the main shaft is inserted into the bottom of the gearbox wherein the fan and its axle are connected to the gearbox.

This is when the tail section is attached to the gearbox wherein the pump is hooked to the main shaft to make the windmill operational.

Solar Vehicle

Solar energy is one of the many renewable sources of energy that is used for fueling vehicles, running consumer products and for the efficient running of homes and business establishments. Solar power is harnessed with the help of solar cells and solar panels which are placed in the item that has to be powered.

The solar car is something that is envisioned to materialize in the future, with some countries already having solar cars racing across countries.
With this, it is proven that it is viable to indeed produce and manufacture solar power cars in bulk, in the near future so that everyone will soon own a solar power car.

Of course, once solar power cars are manufactured, it does not implicate that all other fuel sources for cars on highways will be removed. All that is done in solar power cars is the supplementation of traditional fuel with solar energy so that you save not only on your economy, but also save the environment in more ways than one every year.

The solar power cars that are used in races today run only on solar power, and thus look odd in appearance. This is because these cars are designed in such a way that they can collect maximum solar energy with which it is possible for the car to gain the required speed and desired efficiency.

The solar cells used in solar power cars are large, and usually cover the entire vehicle. However in case of commercial uses, solar cells are much smaller and designed so that the vehicle not only looks attractive, but is also efficient in its functioning. Solar cars can be used for short commutes in town as these cars can work only on solar energy.

The batteries found in the vehicle stores excess solar power so that this power can be used when solar power is not available on demand like on cloudy days and at nighttime. The engines found in these solar power cars are very much like the engines found in electric cars found today. In addition to this, the cars are lightweight, so that solar power can be used more efficiently.

At present, there are many types of solar power cars in the development stage today, which are also available for sale. However as these cars are in the developmental stage, the car is not available to the general public. With so many benefits found in solar power cars, its cost will not be much higher than the cost of the traditionally powered vehicles of today.

Another benefit of solar power cars is there is no hassle of stopping at gas stations for gas nor is there the need of getting worried of rising gasoline costs. With a solar power car, you save on the money that you would have otherwise have needed for buying fuel to run your car. In addition to this, with solar power cars you will be doing your bit in stopping global warming problems as there are no fuel emissions from solar power cars.