Mohammed,

Appears to me to be significant in at least two aspects:

-Sanjay

to add to the above answer, energy storage when extensively used in power grid, the reliability of the grid increases as the net outage time will decrease.

adding to that the renewable energy is inconsisent when it comes to wind energy or solar as the wind flow is seasonal and solar energy extraction reduces under cloudy weather condition and also unavailable for the night. To maintain the constant flow we require to store the energy when available in plenty and use them when they are not available. A smart grid becomes smart enough when the storage facilities are available

If we manage to solve the energy storage problem at length all term

problem of energy consumption will be resolved.

In the tomorrow's energy systems, the share of renewable will be very significant. As rightly pointed out by Mr. Ajai, most of the renewable energy sources are highly fluctuating even in a day of 24 hours. Therefore, in order to ensure availability of power round the clock, energy storage systems are inevitable. This is particularly significant in the case of tidal, solar and wind energy utilization systems. 

The capacity restriction of Grids also warrants use of energy storage systems, some times. In the case of wind energy, the wind farms are installed in large numbers in areas where the wind potential is high. If all the wind mills work simultaneously, the grid may not be able to carry the power and hence forced to shut down a few numbers (mostly a problem in Tamil Nadu, India). Considering the cost of additional grid and the seasonal nature wind energy, energy storage will be an alternative.

In tomorrow's energy mix, renewable will be predominant and hence energy storage systems plays a vital role.

To compensat the fluctuated functioning in supplied power it is necessary to use an instantaneously storage system such as (inertia shaft).   For great power and for long terms  of storage system we talk today about the turbinated and pumping system which plays a good storage system for the wind generator connected to the grid

Though the trivial function of energy storage is to store energy, there may be several energy market services based on that function: energy market arbitrage, covering peak loads, frequency regulation, spinning/supplemental reserve - unloaded but able to provide power in several minutes, anti-congestion transmission support etc. One can think of these options as business models based on energy storage.

Efficient and economical Energy storage technologies are key to the success of three renewable energy resources: solar photovoltaic, concentrated solar power (CSP) and wind turbines. The reason is that these energy resources are intermittent and to offset this intermittency, means must be available to store the generated energy, in some form, when the sun or wind are available, respectively. The stored energy can then be released when the sun or wind are unavailable.

Here are some of the energy storage technologies:

1) Mechanical energy storage such as compressed air (CAES) and flywheel.

2) Electrochemical energy storage in rechargeable batteries such as Ni-Cd batteries or Li-ion batteries.

3) Thermochemical energy storage using reversible chemical reactions.

4) Super capacitors.

5) Phase change materials (PCM).

6) Water electrolysis to produce hydrogen gas which can then be stored in metal hydrides, chemical hydrides, or adsorbents such as metal-organic frameworks such as MOF-5, etc.

In summary, in order for solar PV, CSP, and wind turbines to be viable, they must be integrated with one of the aforementioned energy storage technologies.

Hope this helps!

Just three major advantages from economic as technological point of view:

a. Flexibility for adaptation of RE (Wind, solar, water, heat,,,) to the balances of day to day demand variations.

b. It is possible to generate strong benefits from cheaper energy resources as wind and solar or biomass....it could increased the competitiveness of those sources under new so call market oriented rules...

c. It will make smart energy systems to get a lot of benefits for society, for example, it will  improve the use of  Smart energy systems from a demand side view. 

regards, hope it will inspired you

Leiner 

Energy storage enable larger penetration of wind and solar, its imperative to view the potential role of energy storage in line with the demand of the electric power system . Storage can equally be an alternative to new transmission and distribution (T&D) especially for additional generation.

Just I want to share our experience. We stored energy in magnesium metal as it is the eight most abundant element in earth crust and readily available in oceans as MgCl2. We proposed a complete energy cycle by: 

1- conversion of solar energy to laser beam

2- utilization of Mg as anode in magnesium air fuel cell

3- reduction of MgO to get Mg again by the solar-pumped laser

I hope within few years this cycle will be effective and economically feasible 

https://www.youtube.com/watch?v=3EKmetdjE-c

Hi Mohammed,

Are you asking the role from a policy perspective or from technology perspective?

From a technology perspective, energy storage is by far the most important challenge that the energy sector is facing (electrical energy in particular), both now and in the future. Finding suitable solutions and technologies for all type of applications needed to electrify all our systems (heating, cooling, transportation, etc...) requires development of multiple methods and devices that can resolve a particular issue. Therefore there is no one solution to all our energy storage needs. Batteries are great for some applications such as transportation (electric cars) and residential level (low capacity) electrical energy storage (from solar PV for example), flywheels and ultra capacitors are best suited for grid ancillary services that require very fast response time, and CAES and pump hydro can provide large scale (MW-GW) storage services.

From a policy perspective, energy storage is the enabler of clean/renewable energy economy. Without addition of acceptable levels of energy storage capacity to the energy/electricity infrastructure, renewable energy sources from intermittent sources (Wind and Solar, which are the only available sources with potential to grow at the levels required to meet global energy demand)can not be integrated into the electrical grid and alternative methods such as curtailment are expensive and wasteful, which in turn increases the production cost and making renewables less competitive. It is also the most economical way to utilize our existing energy infrastructure without significant capital infusion. Therefore, inclusion of energy storage is essential for any climate change mitigation action which is the most pressing energy policy issue for the foreseeable future. As a side benefit, energy storage can help reduce the overall cost and demand of energy by utilizing the existing resources, and as everyone knows, no politician likes high energy prices on their watch!!!