What are Energy Storage Systems and their applications
Energy Storage Systems are essential components and technologies that are used to store energy. This stored energy can then be later drawn upon to perform useful operation. Currently around the world and in Uzbekistan too, lithium-ion Energy storage systems are widely prevalent and dominate others, they work by charging up themselves when connected to unstable energy source such as windmills or solar panels and then later discharging to emit electricity at a stable rate to power houses, appliances, etc. Thus, it eliminates the risk of varying voltage through the user's devices.

Extent and Uses of ESS in Uzbekistan:
Central Asia has faced major energy and water security challenges. Technically, water from the Pamir and Tian Shan Mountain ranges could be sufficient to meet the needs of the countries in the region, if there was no time mismatch between the availability of water for irrigation and electricity generation. While water is required for agriculture in downstream countries like Uzbekistan during the summer, demand for hydro electricity generation is mainly in the wintertime in upstream countries such as Kyrgyzstan. With the implementation of the open-source energy systems optimization, a model approach demonstrates that the proposed "dual water and energy storage scheme", with two different hydrological cycles for up- and down-stream regions, guarantees enough water for energy generation in upstream countries in winter while ensuring water availability for irrigation downstream in summer. Thus, the use of Energy systems in Uzbekistan serves to improve energy security and water resource management while providing the countries with a steady output of electricity. Uzbekistan also has a 1.2MW PV Energy Storage Off-grid Power Supply System which stores energy produced from thermal and solar sources of electricity. 

Problems related to the current secondary battery ESS:

• Thermal Runaway: Thermal runaway is a term used for the rapid uncontrolled release of heat energy from a battery cell; it is a condition when a battery creates more heat than it can effectively dissipate. Thermal runaway in a single cell can result in a chain reaction that heats up neighboring cells. As this process continues, it can result in a battery fire or explosion. This can often be the ignition source for larger battery fires.

• Stranded Energy: As with most electrical equipment there is a shock hazard present, but what is unique about ESS is that often, even after being involved in a fire, there is still energy within the ESS. This is difficult to discharge since the terminals are often damaged and presents a hazard to those performing overhaul after a fire. Stranded energy can also cause reignition of the fire hours or even days later.

• Toxic and Flammable Gases Generated: Most batteries create toxic and flammable gases when they undergo thermal runaway. If the gases do not ignite before the lower explosive limit is reached, it can lead to the creation of an explosive atmosphere inside of the ESS room or container.

• Deep Seated Fires: ESS are usually comprised of batteries that are housed in a protective metal or plastic casing within larger cabinets. These layers of protection help prevent damage to the system but can also block water from accessing the seat of the fire. This means that it takes large amounts of water to effectively dissipate the heat generated from ESS fires since cooling the hottest part of the fire is often difficult.

Introducing the pros and cons of lithium-ion batteries:
As most of not only Uzbekistan but the world's Energy storage systems rely upon lithium batteries it's very vital to list it's advantages and disadvantages.

Advantages:

• High energy density:  high energy density is one of the chief advantages of lithium-ion battery technology. With electronic equipment such as Energy storage systems needing to operate longer between charges while still consuming more power, there is always a need to batteries with a much higher energy density.
• Self-discharge: One issue with many rechargeable batteries is the self-discharge rate. The fac about Lithium-ion cells is that their rate of self-discharge is much lower than that of other rechargeable ESS such as Ni-Cad and NiMH forms. It is typically around 5% in the first 4 hours after being charged but then falls to a figure of around 1 or 2% per month.
• Low maintenance: One major lithium-ion battery advantage is that they do not require active maintenance to ensure their performance.
• Cell voltage: The voltage produced by each lithium ion ESS generally higher than its counterparts. This has many advantages. Being higher than that of the standard nickel cadmium, nickel metal hydride and even standard alkaline ESS, the voltage of each lithium ion cell is higher, requiring less Battery packs in many battery applications. 

• Load characteristics: The load characteristics of a lithium ion cell or battery are reasonably good. They provide a reasonably constant 3.6 volts per cell before falling off as the last charge is used.

• Very high cost:  Lithium ion solar batteries for ESS usually cost around $9,000, but the price tag can run up to $30,000 depending on the manufacturer, included features, and how many batteries you need.
• More likely to catch fire: Anomalies in the constituent elements of a Lithium ion battery pack can lead to it easiy catching fire and being relatively unsafe

• Ageing: One of the major lithium ion battery disadvantages for consumer electronics is that lithium ion batteries suffer from ageing. Not only is this time or calendar dependent, but it is also dependent upon the number of charge discharge cycles that the battery has undergone
• Protection / battery management system required:  Lithium-ion cells and batteries are not as robust as some other rechargeable technologies. They require protection from being over charged and discharged too far. In addition to this, they need to have the current maintained within safe limits. Accordingly, one lithium-ion battery disadvantage is that they require protection circuitry incorporated to ensure they are kept within their safe operating limits.

ESS and recycling used batteries:
In Uzbekistan Battery-based grid energy storage systems—particularly systems based on lithium ion batteries—are in greater use by electric utilities. As a result, better strategies and infrastructure are needed to address the removal, disposal, and recycling of these stationary lithium ion batteries.

But the first challenge in recycling or disposing of Li-ion batteries is that they are classified as hazardous waste, due to their chemistries and combustibility. As a result, many regulatory guidelines must be followed at the batteries’ end-of-use. Having different chemistries, including lithium manganese oxide and lithium nickel cobalt aluminum oxide, complicates the logistics of recycling due to the possibility of mixing different chemicals in unfortunate ways.
On a regional level, local governments should fund the development of safe procedures and solutions for the disposal of Lithium-ion batteries.
Internationally, the World Economic Forum has created a platform called the Global Battery Alliance aimed at creating a sustainable battery supply chain by 2030. These efforts are aimed at reducing the need for extractive material sourcing—often linked to numerous negative environmental and social outcomes—and at the need to decrease the carbon footprint of Li-ion battery production.
As these global and federal efforts to increase battery recycling proceed, it is likely that a key outcome or recommendation will be the need for more regional end-of-use processing plants built to handle Li-on batteries.

What future Lies ahead:
Internationally, the biggest change so far is the rapid deployment of wind, solar, and battery storage driven by falling prices, government incentives, and the climate emergency. Predictions are for global wind and solar capacity to surpass gas and coal by 2024. Which catalyzes the need for ESS availability around the world.
In accordance, as Uzbekistan is aiming at achieving a renewable electricity share (including hydropower generation) of 25% by 2030 it will require extensive use of Energy storage systems installed and maintained. It will be interesting to see how new legislature is formed on this topic and what is implemented in the near future.