Energy and Power Engineering, 2013, 5, 22-25
doi:10.4236/epe.2013.54B004 Published Online July 2013 (
Research on New Compressed Air Energy Storage
Xian Ma1, Jingtian Bi1, Wei l i Ch e n 1, Zhisen Li2, Tong Jiang1
1State Key Laboratory of Alternate Electrical Power, System with Renewable Energy Sources,
North China Electric Power University, Beijing, China
2Tai’an Power Supply Company, Shandong Electric Power Corporation
Received January, 2013
In recent years, wind power generation and photovoltaic power generation have been developing rapidly, and the in-
stalled capacity of the new resources generation has been keeping a fast growth every year. But with the incorp oration
into the grid, the new resources generation that has the properties such as ran domness and v olatility causes certain risks
to the power grid, which results in th e falling of the incorpo ration proportion instead of rising. This paper describes the
current status and development problems of the new energy in China, and gives a brief introduction of characteristics of
various energy storage technologies. This paper focuses on the analysis of the compressed air energy storage technology
in recent years and new developments and the latest technology at home and abroad, additionally, the paper introduces a
new concept of the compressed air energy storage system.
Keywords: New Energy; Wind Power; Power Storage Technology; Compressed Air Energy Storage
1. Introduction
UN Secretary-General Ban Ki-moon, the “Sustainable
Energy for All” initiative was launched in late 2011 , spe-
cified the year of 2012 as “Sustainable Energy for All”
International Year. In the period of fast development of
new energy, China, the United States, Germany, Japan
and many other countries are all striving to fight for the
exploitations of new energy to stimulate the future
economy growth, so the development and utilization of
new energy, energy-saving technologies and energy-
saving products have become the key points of the na-
tional energy strategy for every country.
Coal, oil, natural gas and other fossil fuels will even-
tually dried up, coupled with the needs of environmental
protection, so that large-scale application of renewable
energy is imperative. The renewable energy such as wind
power and solar energy have the properties as random-
ness and volatility, and frequent wind power off-gird
pose a threat to the safe operation of the power grid, the
above situations result in increasing proportion of aban-
doned wind yearly[1]. The combination of Energy stor-
age technologies and renewable energy generation tech-
nology not only can improve the stability of the system
and improve power quality, but also improve resource
utilization. Therefore, the large-scale use of renewable
energy need the support of large-scale and distributed
energy storage technology.
2. Analysis of Energy Storage Technology
2.1. Premise of Energy Storage Technology
According to statistics released by the National Grid, at
the end of June 2012, China's grid-connected wind power
has reached 52.58 million kilowatts and overtaken the
U.S. to become the world's biggest wind power country.
But at the same time the year of 2011 as a turning point
in the development of wind power industry in China en-
tered a period of steady development instead of rapid
growth. In the year of 2011, the china’s wind turbines in
operation were suspended for 19 hours every day, the
amount of 100 billion kWh of wind power was aban-
doned and the percentage of abandoned wind power was
over 12%, which is the equivalent of 330 million tons of
standard coal consumption, or 10 million tons of carbon
dioxide emissions to the atmosphere. The loss was more
than 50 billion that is accounting for nearly 50% of the
wind power industry profitabilit y.
If the new energy generation plants such as wind pow-
er and solar photovoltaic power plants were equipped with
energy storage devices, firstly, the energy storage com-
ponents would adjust the output of the unit and solve the
*Supported by the National High Technology Research and Develop-
ment of China 863 Progra m (2012AA050208).
Copyright © 2013 SciRes. EPE
X. MA ET AL. 23
randomness and uncontrollable problems of the new en-
ergy power generation itself to reduce the impact of the
output variation of the new energy on the grid, secondly,
the devices would store the electrical energy during the
period of abundant electricity and release the electricity
when it is necessary. The combination of energy storage
with large capacity wind power generation system is an
important part of the renewable energy, especially for
wind powe r p la nt s.
Figure 1 represents the development of wind power in
China from 2008 to 2012. It is not difficult to find that
the cumulative installed capacity of wind power grows
fast, but the wind turbines grid ratio shows a downward
2.2. Introduction of Energy Storage Technology
Existing electrical energy storage technologies include
pumped storage, compressed air energy storage, flywheel
energy storage, battery energy storage, superconducting
magnetic energy, super capacitor energy storage and so
on [2].
The flywheel energy storage system absorbs
electrical power from grid and transfers it into
mechanical energy during a low load period and
the fast rotating flywheel functions as prime mo-
tor to drag the generators run when the load need
is tedious [3]. Flywheel system has the advantage
that no friction loss, wind resistance, long life
and no environmental impact. The disadvantage
is that the relatively low the energy density is rel-
atively low and the cost of system security is high,
so this technology doesn’t show the priority in
small system and it now mainly works as assis-
tant for the battery system.
The superconducting magnetic energy storage
system transfers the grid power to magnetic field
energy directly, which doesn’t need the energy
exchange [4]. This storage system is character-
ized by simple techniques, timeproof equipment,
high density, fast response speed, low loss and
costliness. This system is not adapted by distrib-
uted power systems until now.
Super capacitor is mainly used for load smooth-
ing and power quality high peak power occasion s
for a short time in the power system and have not
been widely used because of the expensive price
Battery energy storage system is a chemical
power storage system and the batteries need to
maintain a certain temperature in the work proc-
ess. Proportion of the cost for insulation takes a
big part in existing battery energy storage power
station and when the temperature reaches a cer-
tain limit, there will be a certain security risk [6].
Figure 1. China's wind power development in the
The pumped storage power plant is flexible to
start and stop and able to improve and stabilize
the system voltage. But it requires special geo-
graphical conditions for the construction of res-
ervoirs and dams, and the construction period is
long, the initial investment is huge, and the large
area of vegetation will be submerged and even
cities, which will lead to ecolog ical and immigra-
tion issues.
3. Compressed Air Energy Storage, CAES
Compressed air energy storage is second to pumped sto-
rage in the large-capacity storage technology. Although
pumped storage technology has been developed widely,
but because of its own constraints, there is a growing
hope is attached to compressed air energy storage tech-
nology in large-capacity storage technology [7].
Compressed air energy storage technology made many
breakthroughs in the decade’s years from the traditional
hot generation technology using gas turbine to the cool
generation technology transferring the gas potential en-
ergy of the compressed air to other forms of energy, and
the concept of compressed air energy storage is not lim-
ited to using gas turbin e. The following content will ana-
lyze both characteristics and latest technical development
of hot generation and cool generation of compressed air
energy storage.
3.1. Hot Generation Compressed Air Energy
Hot generation compressed air energy storage is referred
to traditional technology, which is actually gas turbine
power plant for peaking regulation. It uses power energy
to press the air into the underground gas chamber and
store the energy, and releases the high-pressure air that
burning with combustible gas for generation. Compared
with other energy storage technologies, hot generation
Copyright © 2013 SciRes. EPE
CAES has advantages such as large capacity, long work-
ing hours, good economic performance and long life of
charge-discharge cycle and so on. But it has disadvan-
tages, for example, hot generation CAES must still rely
on burning fossil fuels to provide heat with the usage of
gas turbine, which is unable to reduce carbon emissions
and doesn’t meet the requirements of the development of
green renew able energy.
3.2. Cool Generation Compressed Air Energy
The innovative concept of cool generation CAES was
proposed in the past one or two years, which achieve the
exchange between the gas potential energy and other
forms of energy. Such a storage system does not need to
burn the combustible gas, so it will reduce carbon emis-
sions to achieve the goal of the green energy storage.
March 2012, CAES Technology Company Sustain X
obtained the patent of constant-temperature CAES sys-
tem. The patent technology is like: During the high-
pressure air expansion, its temperature tends to fall ac-
cording to the ideal gas law, and then the spray mecha-
nism will release the spray at a suitable high temperature
to make the temperature in the vessel remain at a con-
stant level, so the spray transfers thermal energy to the
gas. During air compression, its temperature tends to rise,
and then the spray mechanism will release the spray at a
suitable low temperature to make the temperature in the
vessel remain at a constant level, so the gas will transfer
thermal energy to the spray and the hot water can also be
used for other forms of acting [8]. Figure 2 is patent
schematic diagram of Sustain X Company. Although in
theory, the efficiency of the constant temperature CAES
system is better than that of conventional systems, the
director Mark Johnson of Advanced Research Projects
Agency of the U.S. Department of Energy project
thought that it may need five years or longer to prove its
economy and find a wide range of applications.
Figure 2. Diagram of thermostat compressed air system of
Sustain X.
In early 2013, Sustain X Company also announced a
U.S. patent, which will collect waste heat for generation
to save the leak energy that was taken away by steam.
Dax Kepshire, Sustain X company vice president, said
that if the system was equipped to a conventional power
plant, which will act as a peak-regulation plant and will
be cheaper than gas peak- regul at i on pl ant.
Sustain X Company uses ground air tank to replace the
cave, which diminish the problem of geographical re-
strictions, and it uses the piston instead of the turbines for
generation in order to reduce the size and cost of the gas
In addition to Sustain X Company, Danielle A • Fong,
the co-founder of Light Sail Energy Company, founded a
compressed air energy storage technology, which is still
based on CAES, but the difference is that the technique
uses the piston divides the cylinders into two parts. The
piston will move during the high-pressure gas expansion
or the gas compression and drives piston rod, which will
achieve the exchange between the gas potential energy
and mechanical energy [9]. Figure 3 is patent schematic
diagram of Light Sail Energy Company. While the exist-
ing difficulty is that the temperature will reach 1000℃
when the air is compressed, this means a large part of
loss of energy by the way of heat. She invents a tech-
nique that the hot water is separated away in the process
of the air compression compressed air and uses the ther-
mal energy through the circulation loop to minimize the
loss [10]. Danielle believes that her approach would cost
only 1/10 compared with the same power of the battery
Although China's CAES technology researches and
projects are still focused to the use of the gas turbine
power generation, the concept of combination between
compressed air energy storage and pumped storage is
proposed, and the patent of water-gas encompassing
vessel energy storage system is one example. During air
expansion, the compressed air stored in the vessel is not
used to combust in a gas turbine, but rather the air push
the water flows from the vessel to the low-pressure pool
Figure 3. Diagram of Danielle A • Fong’s patent technology.
Copyright © 2013 SciRes. EPE
Copyright © 2013 SciRes. EPE
ment of various energy storage technologies also make a
new turn for the new energy grid operation. The cool
generation compressed air energy system technology
brings a possibility for green and economic energy stor-
age technology. The future energy storage system needs
a variety of storage patterns to match up with each other.
[1] U.S., “Energy Information Administration,” Renewable
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Figure 4. Diagram of patent technology of water-gas en-
compassing vessel energy storage system . [2] G. Rachel, “2009 Renewable Energy Data Book-
,Washington,” DC:US Department of Energy, 2010.
and drive the turbine into generation. During air com-
pression, the air pump uses the power energy squeeze the
air into the vessel, and the water pump extracts the water
from low-pressure pool into the vessel [11]. Figure 4 is
patent schematic diagram of water-gas encompassing
vessel energy storage system. The system uses the hy-
droturbine for generation, which will obtain higher effi-
ciency of energy exchange than the traditional CAES
technology. But the technique has shortcoming either, for
example, during the water flow promoted by the high-
pressure air, the gas volume increases, and the pressure
gradually reduces, so the pressure forced on the hydro-
turbine is not constant, which will lead to low-efficiency
operation of hydroturbine and off-generation beyond a
certain pres sure ran g e.
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and Frequency Control of Wind Power Generation,” Pro-
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The innovation of CAES technology has raised the
possibility of a new green and low consumption energy
storage technology; however we also need to constantly
improve and perfect these technologies in order to
achieve the goal of the green and economic energy stor-
[8] X. Sustain, Inc.High-Efficiency Liquid Heat Exchange in
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4. Conclusions
The large-scale usage of renewable energy and grid op-
eration needs the support of large-scale and distributed
energy storage technology, and now the rapid develop-
[11] H. R. Wang, “Water-gas Encompassing Electric Power,”
Energy Storage System: CN, 102434362A [P/OL]. 2012-