FUEL CELLS

A fuel cell is an electrochemical cell that produces electricity from a fuel tank. The electricity is generated through the reaction, triggered in the presence of an electrolyte, between the fuel (on the anode side) and an oxidant (on the cathode side). The reactants flow into the cell, and the reaction products flow out of it, while the electrolyte remains within it. Fuel cells can operate virtually continuously as long as the necessary flows are maintained.
Fuel cells are different from conventional electrochemical cell batteries in that they consume reactant from an external source, which must be replenished – a thermodynamically open system. By contrast, batteries store electrical energy chemically and hence represent a thermodynamically closed system. Many combinations of fuels and oxidants are possible. A hydrogen fuel cell uses hydrogen as its fuel and oxygen (usually from air) as its oxidant.
Problems with the Fuel cells:-
• There is no accessible natural reserve of uncombined hydrogen, since what little there is resides in Earth's outer atmosphere.
• One existing method of hydrogen production is steam methane reformation; however, this method requires methane (most commonly available as natural gas, which raises sustainability concerns.
• Another method of hydrogen production is through electrolysis of water, in which electricity is used but is generally inefficient and expensive and is rarely used.
• While hydrogen has a very high energy content by weight, it has a very low energy content by volume, making it very challenging to store in average-sized vehicles
• The production of fuel cells for hydrogen cars is often expensive as most designs require large amounts of platinum as a catalyst.
• Most fuel cell designs are not as yet robust enough to survive in below-freezing environments so fuel cells have to work out startup and long term reliability problems
• Other concerns involve the fragility of fuel cells and their tendency to freeze, the flammability of hydrogen, and vehicle and infrastructure production costs.

ADVANTAGES OF FUEL CELLS
• Traditional internal combustion engines typically have efficiencies of around 30%, whereas fuel cells can achieve 40-70% efficiency.
• Hydrogen production using renewable energy resources would not create nay harmful emissions or, in the case of biomass, would create near-zero net emissions assuming new biomass is grown in place of that converted to hydrogen
Problem statement :-
• Suggest some method to produce inexpensive fuel cells that are robust enough to survive the bumps and vibrations that all automobiles experience? You can achieve this by replacing platinum by some other catalyst.
• Use geothermal power or wind or some other renewable source to produce hydrogen
• Devise a method for safe and cheap storage of hydrogen

NON CONVENTIONAL AND RENEWABLE ENERGY

Biomass is the most common form of renewable energy. The cultivation and combustion of solid biomass, or the thermal utilization of sewage sludge is considered to decrease the net emissions of CO₂

The type of biomass required is largely determined by the energy conversion process and the form in which the energy is required.

There are different types of biomass which could be used as energy source in power production:

(a) surplus and by-products from agricultural activities .e.g., straw,

(b) fast growing energy plants from reutilization of areas which become available by a necessary reduction of agricultural overproduction

(c) wood waste from forestry or wood processing.

In order to achieve a noticeable CO₂ reduction, as well as fossil fuel substitution, it is desirable to use fairly large quantities of biomass for energy production. However, an exclusive biomass utilization would consequently lead to the construction of many decentralized plants, which is time-consuming and would require high financial investments as well as large storage capacities due to the seasonal fuel availability. Co-combustion, in contrast, is considered to be a cheap option for utilizing the existing biomass resources.

Keeping all the above points in mind

Develop a method for production of electricity using biomass that can make Indian villages self sufficient for their energy requirements. It should be cost effective, efficient and large scale.

Find out a substitute for gasoline used in vehicles using biomass.

Suggest methods to make some of the industries like pulp and paper self-sufficient for their energy requirements using biomass.

ELECTRICITY STORAGE TOOLS

The wind doesn’t always blow and sunlight isn’t always striking every solar panel. Renewable energy desperately needs a very big battery, a load leveler. Without some form of energy storage, renewables are physically limited to less than a twenty percent share of the grid. At twenty percent, renewables are more of a headache than a resource for a grid manager. Electricity storage tools are very expensive. Too expensive to justify on their own or at societal scale.
The renewable vision is that hydrogen will be the renewable society’s electricity storage tool, load leveler and transportation fuel.
But the problem is that hydrogen is a lousy load leveler and efficiency of conversion of hydrogen to electricity is just 25% and this problem is essentially unsolvable because it is rooted in thermodynamics
Now you have to find out more-efficient electricity storage tools that can store energy generated by the renewable sources like wind and solar energy and these electricity storage tools should not be in use already. You should also come up with a feasible and cost-efficient method of using these electricity storage tools to store electricity and also find out the cost incurred in doing so.
Moreover, even renewable energy must be stored in order to make it reliable. Wind blows intermittently and so some form of storage is required to compensate for calm periods, and solar energy is not effective on cloudy days so stored energy must be available to compensate for the loss of sun energy.
Go through the following links to start with :-
Grid_energy
Energy storage