As per the 2019 edition of the BP Statistical Review of World Energy report, in 2018, the worldwide demand for energy grew by 2.9%, which was significantly higher than the previous 10 years’ average of 1.5%. This was a result of the increasing population around the world, especially in Asia-Pacific (APAC) and Latin America, which is leading to the rising demand for residential, commercial, and industrial infrastructure. With the rising consumption of electricity, the emission of greenhouse gases (GHG) has also increased, finally reducing in 2019, as per the International Energy Agency (IEA).

The IEA credits this decline in GHG emissions to the increasing usage of electricity generated from the sun, wind, and nuclear reactors. On the basis of such factors, P&S Intelligence has forecast rapid growth for the mechanical energy storage market around the world for the next 5–10 years. Though renewable energy is the best alternative, currently, to fossil-fuel-based energy, its output is not always reliable, which creates the need for efficient methods of energy storage. Among these, mechanical energy storage methods are rapidly becoming popular, as setting up these systems is more-cost-effective than others, including thermal, electromechanical, and chemical.

There are three major types of mechanical energy storage systems: compressed-air energy storage (CAES), flywheel energy storage (FES), and  pumped hydro storage (PHS). Among these, PHS is the most widely deployed technology around the world, because, using it, almost 80% of the energy can be recovered. A PHS system is much like a conventional dam-based hydroelectricity system, involving the storage of water in reservoirs created at different altitudes; only here, the water is not released into the river, but sent back and forth between the two reservoirs.

During periods of low electricity demand, the water from the lower reservoir is pumped to the higher one, which leads to the creation of potential energy. When the energy demand increases, the water from the upper tank is led into the lower one at a great speed, to drive the turbine–alternator system to produce electricity. After the demand–supply gap reduces, the water from the lower reservoir is again pumped back to the upper one. The reason this technology is so popular is that its scientific principle is quite simple and other mechanical storage technologies are not able to produce such a high power output.

Compared to the $100–1,000/ kilowatt-hour (kWh) required to set up other energy storage systems, a PHS system costs merely $21/kWh. Similarly, the installation cost for a CAES system comes to around $53/kWh. Therefore, countries around the world are rapidly adopting mechanical energy storage technologies to create electricity cleanly and balance the load efficiently. This also makes the grid more efficient and protects it from overloading, with a consistent electricity supply.

Currently, Asia-Pacific (APAC) accounts for the highest mechanical energy storage capacity, as India and China are two of the global leaders in producing and using renewable energy. The India Energy Storage Alliance (IESA) says that by 2025, India will account for a total energy storage capacity of 300 Gigawatt-hours (GWh), for which an investment of $3 billion would be required. Similarly, driven by the U.S., the installation of such systems would also be quite significant in North America. In 2017, though the U.S. had an electricity generation capacity of 4 billion Megawatt-hours (MWh), it could only store 431 MWh.

Thus, with the focus on renewable energy increasing and mechanical energy storage systems providing a cost-effective way of enhancing the output, their installation rate is expected to keep surging in the coming years.