Posted tagged ‘solar cells’

Artificial Leaf Solar Power

October 3, 2011


Photosynthesis is the process by which plants, some bacteria, and some protists use the energy from sunlight to produce sugar, which cellular respiration converts into ATP, the “fuel” used by all living things. The conversion of unusable sunlight energy into usable chemical energy, is associated with the actions of the green pigment chlorophyll.

They release molecular oxygen and remove CO2 (Carbon Dioxide) from the air.

ATP: Adenosine Tri-Phosphate (ATP)  Here the energy is stored in living systems; it consists of a Nucleotide (with Ribose sugar) with Three Phosphate groups.

Why is photosynthesis important:

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Nearly all living things depend on the energy produced from photosynthesis for their nourishment. Animals need the plants for food as well as oxygen. Only green plants are able to change light energy into chemical energy stored in food, thus they are vital to life on Earth.

Solar cells:

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Conventional solar cells are also called as Photo Voltaic Cells. These cells are made out of semiconducting material, usually silicon. When light hits the cells, they absorb energy though photons. This absorbed energy knocks out electrons in the silicon, allowing them to flow. By adding different impurities to the silicon such as phosphorus or boron, an electric field can be established. This electric field acts as a diode, because it only allows electrons to flow in one direction. Consequently, the end result is a current of electrons, better known to us as electricity.

Drawbacks of Solar cells:

They can only achieve efficiencies around 10% and they are expensive to manufacture. The first drawback, inefficiency, is almost unavoidable with silicon cells. This is because the incoming photons, or light, must have the right energy, called the band gap energy, to knock out an electron. If the photon has less energy than the band gap energy then it will pass through. If it has more energy than the band gap, then that extra energy will be wasted as heat.

Artificial Leaf:

Mixing of Photosynthesis + Conventional Solar Cells + Hydrogen Fuel Cell

26 Sept. 2011, Cambridge, MA - MIT professor Daniel Nocera has developed an artificial leaf chip that can split water molecules using light. Photo by Dominick Reuter

This Leaf device combines a commercially available solar cell (Silicon) with a pair of inexpensive catalysts made of Cobalt and Nickel that split water into Oxygen and Hydrogen. The hydrogen can be stored and used as an energy source. (For example to power a fuel cell).

The collection and storage of the sun’s energy as hydrogen fuel is a key step in overcoming one of the limitations of solar power — it generates energy when the sun is shining, but it needs to be stored somewhere to be useful at night and in cloudy weather. Batteries are one place to store the energy, but it is limited. Storing solar energy as hydrogen fuel could be an answer for producing the electricity continuously.

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Using this approach, a solar panel roughly one square meter bathed in water could produce enough hydrogen to supply electricity for a house.


September 10, 2011

solar-auto-carsSolar 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.


September 10, 2011

wiring-homeSolar energy is one of the more sought after sources of energy in the market today.

With solar energy, air pollution is reduced as there are no fumes that are emitted while working with solar energy. Moreover, solar energy is available for free; where you only have to pay for the solar energy system, its installation and wiring.

The wiring of a home that is to run on solar electric power has to be done by a skilled person, and with care to ensure that electric devices and appliances in the solar powered home are used safely.

However if you intend to plan or design a solar home, it is better to do so after understanding the process of getting solar power from the solar cells and panels to the outlets and appliances found in your house.

Though homes with solar power and homes with fossil fuel generated power sources use 120 volt alternating current, there are differences in the wiring and additional equipment that is usually used in the expensive electric power grid.

Though you will have to pay some initial expenditure for installing your solar energy power system, this investment pays for itself over a period of years where you in fact, end up saving money you would have spent paying for the costs of increasing traditional power rates.

It is important to insulate your home well when planning a solar home. Buy windows that are not only well sealed, but also double paned. They have to be installed so that there is no seepage of drafts around the window frames and door jams. You also have to be specific about attic and ceiling insulation as the less the amount of heat and cool air that is lost to the outside, the les is the energy required to replace comfort controlled air. With this, there is less demand made on your solar electric power system.

Your solar power generator needs a battery meter and a start-stop switch. You need more electric outlets here than in a non-solar home so that task areas are lighted and not entire rooms. Place a few low voltage outlets to save money in devices using little energy like telephone answering machine, fan and others.

Don’t forget to place a few electric outlets outside so that the solar electric power system can be used for powering tools and for any outside activities. Remember that you get lots of extra free power in summer where you can think of using an electric lawn mower or fountain pump. You could also consider providing lighting for a shed or garage for power tools and emergency battery charger to start your car with.

You could also install special 12 volt DC motion sensor lights at the entrance of your home so that it lights up even if the inverter is in idle mode. Remember that solar powered homed don’t allow for 220 volt AC appliances operating from 240 volt AC section of wiring.

If you need such appliances, you will have to depend on traditional power to use them. However it is better to buy appliances using 120 volt models as most equipment are available this way. With this, you will be able to use all your equipment with solar power in your solar power home and thus save lots of money in the fuel costs of your home.