Mass Energy Storage System
As the demand for energy increases worldwide, the use of fossil fuels and
continuous emission of CO2 has caused pollution and global warming.
In order to suppress greenhouse gas emission, renewable energy such as solar energy,
wind energy and fuel cell, is receiving spotlight and is being disseminated at a fast speed.
However, renewable energy is highly affected by location environment and natural condition,
so there is a lot of fluctuation in its output. Therefore, it is difficult to provide the energy continuously
and a time lag occurs between when the energy is produced and when it is demanded.
Mass energy storage system is considered to be a solution to these problems.
Energy storage system (ESS) is a power feeding equipment that stores excess energy
and supplies it when needed; thus increasing energy effectiveness, utilization of renewable energy,
as well as stabilizing energy supply. Hence, as ESS can perform the role of ‘electricity reservoir,’
that stores surplus electricity and reuse it, it is useful during times of blackout
as emergency power source and also can be helpful managing electric power load.
Regarding its use, mass secondary battery storage system is at the center of large-scale
solar power generation and wind power developing district, while in the cases of electricity surplus
or underload during night time, compressed air or fly-wheel can be applied. Especially on smart-grid,
the energy storage system is becoming increasingly important, particularly the secondary battery
is efficient as it can respond quickly depending on system conditions. Thus, energy storage system
is a newly emerging industry whose market is expected to grow substantially as it is the key technology
in the green industry that creates value such as stabilization of electric supply and dissemination
of renewable energy.
Among diverse types of energy storage system, Redox Flow Battery, one that is most suitable
for large-scale energy storage system, will be looked at in detail.
Redox flow battery
Unlike other secondary battery that stores electric energy in the electrode that includes active material,
redox flow battery is a electrochemical energy storage system that charges and discharges
as the active material in electrolyte goes through redox (reduction/oxidation) process and
directly stores the chemical energy of active material as electric energy.
The redox flow battery comprises of electrolyte tank that decides the capacity of active materials
with different oxidation levels, pump that circulates active materials during charging and discharging process,
as well as stack that is in charge of the output. As the electrolyte tank and stack are separated,
it is possible to freely design its output and capacity, and the constraint put on installation location
is little. Also, the battery does not produce waste such as CO2 and the vanadium active material,
one of electrolytes, can be used semi-permanently, making a very efficient use of resources.
As active material of a redox flow battery, electrolytes produced by liquidating transition metals
such as V, Fe, Cr, Cu, Ti, Sn, Zn and Br in strong acid are generally used, and operating voltage
is determined through the potential difference between anode and cathode active material.
In order to obtain wanted voltage and electric current, stack is connected in a series or parallel
circuit and then laminated.
Redox flow battery is free in planning its output and capacity as well as stable since it operates
in room temperature. It can also be used for a long period time -over 10 years- but has low output
density and energy density.
- Contents -
I. Technology Development Status of Large-scale Energy Storage System
1.1. Concept of Large-scale Energy Storage System
1.2. Types and Features of Large-scale Energy Storage System Technology
- Pumped storage, Compressed air, Lead acid (Lead Storage Battery),
NaS battery, Lithium ion battery, Supercapacitor, Redox flow battery
1.3. Technology Development Status of Large-scale Energy Storage System by Country
- Japan, Korea, China, United States, Europe
II. Redox Flow Battery Technology
2.1. Necessity of Developing Redox Flow Battery
2.2. Understanding Redox Flow Battery
- Concept of Redox Flow, Development History of Redox Flow Battery
2.3. Redox Flow Battery Technology
- RFB ESS Composition, RFB Stack, RFB BOP,
RFB Key Elements (Redox Couple, Bipolar Plate, Membrane)
III. Redox Flow Battery Application Cases
3.1. Load Leveling
3.2. Power Quality Control Applications
3.3. Coupling with Renewable Energy Sources
3.4. Electric Vehicles
Ⅳ. Redox Flow Battery Recent Technology Issue & Development Trend
4.1. Low cost
4.2. High output, large-scale stack
4.3. High energy density
Ⅴ. Redox Flow Battery Patent Trend
5.1. Patent Analysis Range and Standards of Redox Flow Battery
5.2. Patent Trend by Host State of Intellectual Property Office
5.3. Patent Trend of Applicants
VI. Main Research Institutes and Industries & their Technology Development and Business Trend
6.1. United States
- Pacific Northwest National Laboratory (PNNL), Sandia National Laboratories (SNL)
UniEnergy Technologies, Imergy Power Systems, EnerVault, ZBB Energy
- Sumitomo Electric Industries, Ltd., Kansai Electric Power Co., Inc., Ryukyu Electric Power Co., Ltd.
- Fraunhofer ICT (Institute for chemical technology) (Germany), Gildemeister energy solutions (Germany)
REDT UK Ltd. (United Kingdom), EDP(Spain), Plurion Systems (United Kingdom),
ITI Energy (United Kingdom), RISO DTU (Denmark)
- V-Fuel Pty Ltd, Redflow