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