Solar lanterns use solar energy to produce light. They are environment friendly as the light is not produced by burning a fuel like kerosene or by burning candles. These days they are widely being used in rural villages and other such places where there is no electricity or people cannot afford the electricity cost.
In urban areas, they are becoming really popular as people are using them in case of power failures. They are portable sources of light because they can be carried from one place to another easily. Contemporary solar lanterns come in varying styles and design and that is the reason why people do not hesitate to keep them inside their house. These lanterns are a one time investment device because afterwards, they use natural source of energy which is sunlight and convert it into electricity. Although very little maintenance would be required for few parts.
A Solar lantern consists of four main components:
a) Solar Panel (usually called Photovoltaic panel)
b) Rechargeable battery
c) High Change Control Circuit
d) High efficiency lamp
During the daytime, they convert energy received from sun into electricity with the use of solar cells and store it in rechargeable batteries. High change control circuit helps in protecting rechargeable batteries from getting overcharged. For enlightenment, high efficiency lamps like compact fluorescent lamps (CFL) are used. CFL’s have good life of around 3 to 4 years. These days, instead of a CFL, ultra bright and highly efficient light emitting diodes (LED) are also used. Use of LED’s in solar lanterns requires small size solar panel and battery, thereby reducing the overall cost.
They also provide an option to be charged from alternate current (AC). This helps in providing light even when there is not ample sunlight for the lantern to get charged. Such lanterns are excessively being used in residential areas and farmhouses these days.
Advantages
a) They use renewable resource of energy, that is, sunlight. Other resources such as coal and kerosene are non renewable and have finite supplies.
b) Solar lanterns continue to work even in the case of power failure as they run on solar energy and not on electricity.
c) They are cheaper source of lightning. Other lightning systems require wiring setup whereas solar lanterns are portable and do not need any wiring.
d) The greatest benefit of a solar lantern is that it does not emit fumes, thereby, not contributing to global warming.
e) Sun is the natural source of energy, thus operating cost of solar lanterns is very low.
Disadvantages
a) They are unable to charge on cloudy days which means that the lantern would not emit light in the evening.
b) The LED’s used in solar lantern emit dull light as compared to the traditional incandescent bulb.
c) The rechargeable batteries used in solar lanterns have short life span which is around 2 years. Thus, these batteries need to be replaced timely.
d) The solar light fixtures are usually little more costly than the traditional light fixtures.
e) Once charged, they light up for few hours due to the less battery backup.
Solar Cooker is a device that uses natural energy of sunlight to cook or heat food. Contrary to other forms of cookers wherein they use either electricity or fuel, solar cooker uses natural form of energy that is sunlight, which incurs no cost. Thus, solar cooker helps in saving money as well as in protecting our environment from air pollution caused by burning of fuel. Because of their low cost many nonprofit organizations are promoting their use in villages or in places where people cannot spend much on fuel or electricity. It works on following principal:
Solar cooker comes up with a reflective glass that is used to capture sunlight to a defined area where the cooking utensil is placed. Cooking utensil is either colored black or kept in a black cover to absorb maximum heat from reflected sunlight. The cooker is insulated from outside or kept in a glass cover to trap the heat . This helps in reaching same heating temperature inside cooker irrespective of cold or hot weather outside.
The major drawback with solar cooker is that it can not be used when there is no sunlight which is in early morning or when the sky is overcast. With solar cooker, always there has to be an alternate way of cooking. Moreover the time solar cooker requires to cook food depends upon several factors like weather, number of reflectors used etc.
Few types of solar cookers that are in use today are: Box Cooker, Panel Cooker and Parabolic Cooker.
Box Cooker
It consists of a box made up of any type of material such as wood, cardboard, plastic etc. The cooking utensil is placed inside the box which is usually dark colored or colored black for the purpose of trapping heat. The box is covered with a reflective glass or plastic which allows sunlight to reach the cooking utensil placed inside the box. The UV rays reach the inside box converts to infrared rays which heat up the utensil and are not allowed to go back because of the reflective cover. The box cooker is usually made up of two boxes of different sizes. The smaller one is placed inside the bigger one and the gap is filled up with an insulated material like crumbled newspaper, wool, fiberglass, hay etc. This prevents loss of heat due to conduction. Box cooker can usually reach a temperature of 150 degree Celsius or 300 degree Fahrenheit. Such temperature is sufficient to cook any food.
Panel Cooker
It consists of a cooking vessel which is usually darkened or colored black. This vessel is covered by a glass case and a glass top. A reflective panel covers this vessel and helps in concentrating sunlight onto the vessel which thereby helps in cooking food. Panel cooker reaches temperature of 225-250 degree Fahrenheit which is sufficient to cook any kind of food.
Parabolic Cooker
It consists of a reflector that is parabolic in shape. The cooking utensil is placed at a place in the setup where there is maximum concentration of sunlight. Such cookers reach high temperature more rapidly but frequent adjustment of the concentrator is required for maximum effectiveness.
Ever thought how cheap will travel become once cars use sun as the fuel? Are you also wondering about a fuel that is cost free and is abundantly available? Wait no more! A concept which was once unimaginable has been picking up progress as people have started realizing solar energy’s benefits. They have realized the importance of saving the environment and truly understood sustainable development. This is the only reason why people have been trying to invent a solar car for so long now. From 1970s itself, people have been trying to build a solar car. The ability of human mind is fully depicted when we talk about solar cars.
Solar energy is a renewable source of energy and it shall never end. Hence, it must be fully exploited. Solar cars in one way protect non-renewable resources like fossil fuels which will help the environment grow. With solar panel price set to go down in the coming years, solar cars will definitely be more popular in different parts of the world.
A solar car is a car which runs on sun’s energy. Photovoltaic cells (PVC) are used in cars to harness sun’s energy. These cells come in direct contact with the sunlight and store the energy which they receive from the sun. A semiconductor, known as silicon, is used to trap or absorb energy from the sun. Then there is a flow of electrons which generates electricity. This stored energy can be later used to run vehicles. It depends on the size and type of photovoltaic cells that how long the car will run. The more expensive the cells, more energy will they store. One very important thing about them is that they can be used with unnatural light. However, when used with unnatural light, the speed and the mileage will be very low as compared to solar energy.
The work done so far on PVC is considerable. However, even as of now they are very bulky and a bit unreliable. Car’s mileage is also dependent on the weight of the car. More the weight less shall be the mileage. So, it is of due importance that solar cells are designed in such a manner that they are not heavy, yet they are efficient.
The solar cars are definitely going to be in high demand due to rising prices of petrol and gas. Petrol and gas are also very difficult to be extracted from land. They are also non-renewable sources of energy and will definitely finish some or the other day. Solar cars are in their nascent stages and need a lot of work to be done to use solar cars in an efficient and effective way. With new and upgraded solar cells being produced, there is a complete assurance that solar cars will replace the traditional cars.
The future of such cars seems bright and in years to come, almost everyone will use solar cars because of their benefits. There are certainly some disadvantages but as the concept grows, better ideas will plunge in to remove the disadvantages. Not only will it help to reduce dependence on fossil fuels in the present but also provide resources to our coming generations.
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