There is a growing recognition in the energy sector of the pressing
need to address climate change by shifting towards renewable energy
sources and reducing reliance on fossil fuels. The energy sector has
effusively recognized the pressing need to address climate change by
shifting towards renewable energy sources and reducing reliance on
fossil fuels. However, these alternative sources of energy have their
own limitations such as seasonal variations, location-specificity, or
temporal fluctuations. Additionally, the power demand from existing
power grids is subject to fluctuations, including seasonal or daily
variations.
Seasonal fluctuations in power demand arise from changes in weather
patterns, daylight hours, and temperature, which impact the demand for
electricity. For instance, during winters, the demand for electricity
increases as people use more heating, whereas, during summers, the
demand rises due to the use of air conditioning. Diurnal variations in
power demand refer to changes in demand that occur on a daily basis,
owing to regular human activities. Daytime power demand tends to be
higher due to increased industrial activity, office work, and the use
of appliances, while night time demand decreases as people sleep and
use fewer devices.
Managing these fluctuations in power demand is crucial for power grid
operators to ensure a stable and reliable supply of electricity. To
address this challenge, power grid operators employ various
strategies, such as adjusting the output of power plants, and
implementing demand response programs that encourage consumers to
reduce their electricity consumption during peak demand.
Energy storage systems are critical for addressing the challenges and
ensuring a reliable power supply to consumers, while also promoting
sustainability. The most common energy storage system is the battery,
which is recharged by connecting it to a power source and discharged
to provide power. With a little higher than 50% growth of the energy
storage capacity, worldwide, battery storage is accounting for 85% of
the new capacity additions. However, the high cost of installation,
indirect pollution, lifetime, etc. are some of the factors that remain
significant barriers to the widespread adoption of the technology.
There are other energy storage systems as well, such as pumped hydro,
compressed air, mechanical energy storage, and thermo-mechanical and
thermo-chemical storage systems. One such system is the cryogenic
energy storage system, which can adapt to fluctuations in energy
demand and is environmentally friendly. Cryogenics is the science and
technology that deals with applications operating below a temperature
of -150 Degree Celsius.
Ever wondered if the air we are surrounded by, the air that we
breathe, can be used for storing energy? This has indeed been achieved
– scientists, all across the globe including the author, who played
a pivotal role in initiating research on one such system in India,
have developed machines that use air to store energy. Such a machine
literally breathes in the air from the atmosphere, liquefies it for
storage, regenerates power using that stored liquid when required, and
breathes out air back into the atmosphere. This machine is called a
cryogenic energy storage system as it works between temperatures
ranging from room temperature down to -196 Degree Celsius. This
finding assumes significance in the present global scenario of
increasing the gap between the supply and demand for energy and power
than the existing resources could provide. This technology has added
advantages such as a long lifetime, matured technology for most of the
equipment in the system, comparatively low cost, independent of
location, storage for a longer duration, asynchronous charging, and
discharging, and easy transportation of the stored energy. By the way,
did you know that the charging and the discharging systems don’t have
to be together in the same place for a cryogenic energy storage
system? It’s true! They can be miles apart from each other and still
get the job done.
In this system, the air is the only component that goes in and comes
out. And this system is predicted to have a life of more than 30
years, which renders it environmentally friendly and sustainable.
Additionally, it does not require any fuel to burn, electrochemical
reactions, constraints on the supply of the storage material, or need
of any facility to store the storage material, but using the
abundantly available air that comes for free. One such system has
already arrived at the market with an affordable and competitive price
tag per MWh of electrical energy.
Interested in knowing more about how cryogenic energy storage systems
work? Check out the next article in this series.