Solar power is a clean way to generate electricity that’s not only environmentally friendly, but economical. photovoltaic modules that gather energy from the sun, and release it as electricity that can power home or office to save on energy costs while helping protect the planet and to bring clean, reliable energy to residences, business, power-generation plants, schools, factories and areas without access to electricity, as well as other applications such highway and stadium lighting.Photovoltaic modules manufactured by Mitsubishi Electric’s utilize polysilicon technology which is known for their high reliability, high-efficiency, and low environmental impact with 25-year limited warranty on power output.Solar cells have separate connecting tab wiring between the front and back sides. This is an effective step toward optimization of connecting conditions, while curving cell warp to support the move toward thinner solar cells.For the silver electrodes formed on the solar cell surface, an exclusive composition and manufacturing process is used by them that excel in environmental resistance and introduced industry-first introduction of mass-produced “solder-coatingless cells”. This removes lead (traditional lead-solder modules use about 860 grams of lead) which is harmful to the human body, while the expanded light reflection effects with the solderless status improve cell efficiency. Mitsubishi Electric has developed fine grid electrodes with an optimal BSF structure and use of anti-reflective coating for the solar cell manufacturing process which has expanded the solar cell light receiving area to realize high-efficiency cells.Solar cell string pitch have been expanded and the high reflectance back film reflects light to raise module efficiency.Use of glass that is cerium-free and high in transmittance has defined a new dimension in high efficiency, free of initial deterioration.
High temperature solid oxide fuel cell (SOFC) uses a hard ceramic electrolyte instead of a liquid and operates at temperatures up to 1,000 degrees C. A mixture of zirconium oxide and calcium oxide form a crystal lattice, though other oxide combinations have also been used as electrolytes. The solid electrolyte is coated on both sides with specialized porous electrode materials. At these high operating temperature, oxygen ions (with a negative charge) migrate through the crystal lattice. When a fuel gas containing hydrogen is passed over the anode, a flow of negatively charged oxygen ions moves across the electrolyte to oxidize the fuel. The oxygen is supplied, usually from air, at the cathode. Electrons generated at the anode travel through an external load to the cathode, completing the circuit and supplying electric power along the way. Generating efficiencies can range up to about 60 percent. In one configuration, the SOFC consists of an array of tubes. Another variation includes a more conventional stack of disks. Since SOFCs operate at such high temperatures, a reformer is not required to extract hydrogen from the fuel. Some demonstration units have capacities up to 100 kilowatts. 
Biodiesel is a mixture of fatty acid alkyl esters made from vegetable oils, animal fats or recycled greases. Biodiesel can be used as a fuel for vehicles in its pure form, but it is usually used as a petroleum diesel additive to reduce levels of particulates, carbon monoxide, hydrocarbons and air toxics from diesel-powered vehicles.
Gasification is a quite complex thermo-chemical process. Conceptually zones of the gasifier may be divided into different stages viz., drying, pyrolysis, oxidation and reduction. The reactions occur at the same time in different parts of gasifier. The generation of gas occurs in two significant steps. The first step involves exothermic reactions of oxygen in air with the pyrolysis gas under fuel-rich conditions. The second step involves the endothermic reaction of these gases largely CO2 and H2O with hot char leading to product gases namely, CO, H2 and CH4.
Fuel cells offer a number of significant advantages over conventional batteries and diesel generators for backup power solutions. These include: greater reliability over a wide range of operating conditions; lower maintenance costs; longer operating life; reduced size, weight, installation footprint; and positive environmental impacts. Hydrogen-powered fuel cells are not only pollution-free, but also can have two to three times the efficiency of traditional combustion technologies. A conventional combustion-based power plant typically generates electricity at efficiencies of 33 to 35 percent, while fuel cell systems can generate electricity at efficiencies up to 60 percent (and even higher with cogeneration). These advantages make fuel cell technology ideal for telecommunications backup applications. 
One of the major drawbacks of the DMFC is that the low-temperature oxidation of methanol to hydrogen ions and carbon dioxide requires a more active catalyst, which typically means a larger quantity of expensive platinum catalyst is required than in conventional PEMFCs. This increased cost is, however, expected to be more than outweighed by the convenience of using a liquid fuel and the ability to function without a reforming unit. Since methanol is supposed to be toxic some companies have embarked on using ethanol to substitute for methanol. More than 30% of world ethanol production is from corn, the rest is produced from suger based raw material like juices of sugarcane or beet and also their molasses. There are other grains used in the production of ethanol which is rice, wheat, rye, sorghum or tubers like cassava / tapioca. Cellulosic biomass, holds tremendous promise as a feedstock for ethanol production due to its widespread availability and potential for high fuel yields. Examples of sources for celluosic ethanol include corn stover , wheat and barley straw, sugarcane or rice bagasse, sawdust, paper pulp, small diameter trees and dedicated energy crops such as switch grass and other fast growing grasses. Study is still going in making cellulosic ethanol more viable. Hence developing a Direct Ethanol Fuel Cell (DEFC) has gained importance. The performance of the DEFC is currently about half that of the DMFC, but this gap is expected to narrow with further development. 
Hydrogen is often spoken as an environmentally-friendly fuel for road vehicles of the future. When consumed in a fuel-cell powered electric car, it produces nothing more than pure water as a by-product. However, many technological challenges remain before it can be used commercially. In particular, hydrogen has a low energy density compared to conventional fuels and therefore it must be stored as a liquid or an extremely high pressure gas to ensure that reasonable distances can be traveled before refueling. Current materials that can easily absorb and discharge hydrogen near room temperature contain transition metals and the storage process must be catalysed by expensive precious metals such as platinum. This makes them too heavy and too expensive for commercial use. But Douglas Stephan and colleagues at the University of Windsor have developed the first non-metallic solid material that can absorb and store hydrogen at room temperature without involving a transition metal. This discovery could lead to the development of low-cost and lightweight materials for the onboard storage of hydrogen fuel in cars. Although the metal-free material offers hope of lighter and cheaper storage materials, it stores less than 0.25% of its weight in hydrogen and researchers say there is still a long way to go. 
A central component of a solid oxide fuel cell is the electrolyte which consists of an oxygen ion conducting ceramic material. Such ion conducting materials can also be used for membranes. The membrane route has some environmental advantages and has the potential of becoming cost competitive with the existing industrial routes. A specific use of such mixed conducting membranes is in a membrane reactor for production of synthesis gas which is a mixture of CO and H2, which is the source for a number of industrially important syntheses such as methanol and ammonia and has potential use as electrode materials for solid oxide fuel cells. Presently available membranes based on palladium support a high flux of hydrogen, but their mechanical stability is limited and their catalytic properties favor the formation of coke. 
Photovoltaic (PV) cells are made of special materials called semiconductors such as silicon, which is currently the most commonly used. When sun light strikes the cell, energy knocks electrons loose and the flow of electrons is a current. By placing metal contacts on the top and bottom of the PV cell, we can draw that current off to use externally. Many factors limit the efficiency of photovoltaic cells. Silicon is cheap, for example, but in converting light to electricity it wastes most of the energy as heat. The most efficient semiconductors in solar cells are alloys made from elements from group III of the periodic table, like aluminum, gallium, and indium, with elements from group V, like nitrogen and arsenic. One of the most fundamental limitations on solar cell efficiency is the band gap of the semiconductor from which the cell is made. The maximum efficiency a solar cell made from a single material can achieve in converting light to electrical power is about 30 percent; the best efficiency actually achieved is about 25 percent.
Initially developed in the early 1990s, DMFCs were not embraced because of their low efficiency and power density, as well as other problems. Improvements in catalysts and other recent developments have increased power density 20-fold and the efficiency may eventually reach 40%. The technology behind Direct Methanol Fuel Cells (DMFC) is still in the early stages of development, but it has been successfully demonstrated powering mobile phones and laptop computers potential target end uses in future years. DMFC is similar to the PEMFC in that the electrolyte is a polymer and the charge carrier is the hydrogen ion (proton). However, the liquid methanol (CH3OH) is oxidized in the presence of water at the anode generating CO2, hydrogen ions and the electrons that travel through the external circuit as the electric output of the fuel cell. The hydrogen ions travel through the electrolyte and react with oxygen from the air and the electrons from the external circuit to form water at the anode completing the circuit. 
Biodiesel is the name for a variety of ester-based oxygenated fuels derived from natural, renewable biological sources such as vegetable oils. Biodiesel operates in compression ignition engines like petroleum diesel thereby requiring no essential engine modifications. Moreover it can maintain the payload capacity and range of conventional diesel. Biodiesel fuel can be made from new or used vegetable oils and animal fats. Unlike fossil diesel, pure biodiesel is biodegradable, nontoxic and essentially free of sulphur and aromatics. The oil extracted from the seeds of Jatropha is mixed with methanol at a proportion under a particular temperature. This solution is continuously stirred for two hours. During the above process, glycerol present in the solution separate out; which when settled can be separated out. Whatever is left after removing the glycerol is the liquid fuel. When the liquid fuel is washed twice, purified biodiesel is obtained. This could be used directly for running the engine. Advantages of biodiesel are:
India imported about 36.5x106of its diesel requirement in the year 2003 and demand for diesel is also increasing every year. Biodiesel is the only fuel to meet out increasing diesel demands. So even mixing of 20 per cent with diesel fuel by biodiesel can help India save 7.3 x 106 tonnes of diesel per year. In India, about more than 14 million hectares land is cultural wasteland while more than 24 million hectare land is fallow land . The use of non edible oils compared to edible oils is very significant because of the increase in demand for edible oils as food and they are too expensive as compared with diesel fuel. 
The direct use of raw jatropha oil in engine by several researchers and they reported formation of carbon deposits, incomplete combustions and results in reducing the life of an engine due to high viscosity of curcas oil. Similar problems reported by many researchers when they using raw vegetable oils as engine fuel. When using refined curcas oil blends in precombustion chamber engine, results for thermal efficiency and emission were fair compared with diesel No.2 diesel. The problems of filter blockage, carbon deposits and oil incompatibility with fuel line materials were also noticed. It is also reported that jatropha oil blending up to 40 to 50 per cent with diesel fuel used in engine without modifications. However, Acrolein is high toxic substance released from the engine due to thermal decomposition of glycerol present in the oils. The problems encountered in raw oils are solved by forming biodiesel, which is non toxic, eco-friendly fuel, and have similar properties of diesel fuel. 
The best form of renewable energy available to the developing countries is the solar energy. This is due to the fast changing world energy scenario, particularly for emerging economies such as India and China on account of the rising costs of oil and coal. India is a small player in the world photovoltaic cells market, yet 69% of its modules are exported. The rest are put to use mainly in telecommunications and lighting homes. Solar PV modules are developed in the industrialised countries despite the fact that their energy efficiency is 15-20% is because of rising fossil fuel costs and the need to contain greenhouse gas emissions. Germany, Spain, Japan, China and the US are the leading PV module makers, with Germany making up almost half the world’s output of about 3,800 MW. China’s PV cell output was 820 MW in 2007, ten times that of India. It is time India broke into the big league, to take advantage of global technological transition. If wind power generation has risen sharply in the last decade to account for 80% of India’s renewable energy output of over 10,000 MW, the next decade could belong to solar. While the installed capacity for wind power is limited close to 8,000 MW, which is little more than 2 MW in the case of grid-connected solar power. 
The alkaline fuel cell consists of electrodes and chambers for electrolyte and gas supply. Electrodes viz., anodes and cathodes are for operation with hydrogen and air. Each electrode consisted of 3 layers; a current collecting nickel mesh, a catalytic layer and a hydrophobic gas-porous PTFE (Teflon) layer at the gas side of the electrodes. The catalytic layer is a calendered mixture of platinized carbon particles with PTFE, the only difference between anodes and cathodes is the type of carbon substrate used for the catalyst in order to cope up different electrocatalytic environments such as reduction or oxidation. The carbon substrate used is powdered charcoal. The catalytic loading is 0.3 mg platinum (Pt) per square centimeter of cell area. The electrodes are designed to operate at atmospheric pressure and had a thickness of 0.4 mm. there are several modules and each module has the electrodes combined together using a semi industrial two step manufacturing process. The frames are of thermoplastic material injection moulded and friction welded. 
Agricultural or agro-industrial biomass is generally difficult to handle because of its bulky and scattered nature, low thermal efficiency and copious liberation of smoke during burning. Legal and administrative problems are also encountered with agro-industrial biomass. In order to achieve maximum and efficient exploitation of locally available resources, it is essential to compress them into manageable and compact pieces, which have a high thermal value per unit weight. This process is called biomass briquetting or pelleting. Compressed biomass briquettes are usually cylindrical in shape with a diameter between 30 to 90 mm and length varying between 100 to 400 mm. Briquetting consists of applying pressure to a mass of particles with or without a binder and converting it into compact aggregate.
Due to growing worldwide concern about the environmental impacts of fossil fuels, particularly global warming and nuclear risks, there is currently a resurgence of interest in biomass energy, since potentially it can satisfy a much larger energy demand. According to a report, under the minimum case scenario, biomass is the most important of the renewable and is projected to account for 45% (243 mtoe) of the contribution by renewable to world energy by 2020 and to about 65% of energy use in developing countries. At present however, the residues are normally under utilized. CO2 emission could be avoided significantly by utilizing normally unused residues in place of fossil fuels, wherever possible.
Photovoltaic systems and power plants have emerged as viable power sources for applications such as lighting, water pumping and telecommunications and are being increasingly used for meeting electrical energy needs in remote villages, hamlets, hospitals and households. PV systems, when used on a large scale, can cut down the need for extending the distribution grids in rural areas and the resultant losses in transmission. Solar Photovoltaic (SPV) water pumping systems are technically proven and have potential of replacing diesel pumping systems, commonly used in un electrified locations for lifting water from shallow depths. The pumps can also bring the benefits of irrigation and drinking water supply in backward areas not served by the exiting grid and where supplying diesel is a problem. It is clear that there is a vast potential for the use of solar photovoltaic technology in the developing countries. 
One major difference between the MCFC and SOFC technologies is that the MCFC uses readily available materials and predictable manufacturing technology, particularly in its use of sheet metal parts. In contrast, the prospects for manufacture of the SOFC are not very predictable, since it will require sophisticated ceramic fabrication techniques that go beyond the state of the art for production processes. Two versions of the SOFC technology exist. The first is a conservative version in pre prototype stage, whereas the second is an idea that is only in the design stage. Since the latter is only on the drawing board, any conclusions concerning its fabricability and performance will involve many technological extrapolations. 
Presently, cellulose is mainly processed by fermentation. For the fermentation process to take effect yeast must be added to the cellulose, this will allow the sugar to be fermented into ethanol as well as carbon dioxide. The next step is the distillation process which is necessary to remove the alcohol from the solids and the water. However, splitting cellulose into its individual sugar components, which can then be fermented, is a slow and cost-intensive process. The direct conversion of cellulose into useful organic compounds is thus an attractive lternative.Researchers in the USA and China have now developed a new catalyst that directly converts cellulose, the most common form of biomass, into ethylene glycol, an important intermediate product for chemical industry. A team led by Tao Zhang at the Dalian Institute of Chemical Physics, China and Jingguang G. Chen at the University of Delaware, Newark, USA has developed a novel process. In this the catalyst is made of tungsten carbide and deposited on a carbon support with small amounts of nickel added to improve the efficiency and selectivity of the catalyst system. A synergetic effect between the nickel and tungsten carbide not only allows 100 % conversion of cellulose, but also increases the proportion of ethylene glycol in the resulting mixture of polyalcohols to an amazing 61 %. Ethylene glycol is an important intermediate in the chemical industry. For example, in the plastics industry it is needed for the production of polyester fibres and resins, and in the automobile industry it is used as antifreeze. 
Researchers at the University of Wisconsin-Madison have developed a simple, two-step chemical process to convert plant sugars into hydrocarbon fuels. The compounds created during the process could also be used to make other industrial chemicals and plastics.