Energy storage for a sustainable future - The top 5 trends

Against the background of the rapid growth of global wind and solar installed capacity, the growth prospects of new energy storage are highly certain. The market should not be underestimated. Energy storage international conference and expo(ESIE) is an important event.

Top 10 commercial energy storage manufacturers in China also participated in the exhibition. In the exhibition, exhibitors exhibited their latest products.

Corresponding to the absolute dominance of lithium battery energy storage, the vast majority of  manufacturers exhibited lithium battery energy storage systems. The latest products of manufacturers present five development trends of lithium battery energy storage technology.

Liquid cooling temperature control system becomes standard

The liquid cooling system has high heat exchange efficiency, which can reduce the temperature difference between batteries, reduce the risk of thermal runaway, increase the service life of batteries, and improve safety. In addition, the energy consumption of the liquid cooling system is relatively low.

Compared with the many advantages of air cooling, liquid cooling has become the technical consensus of energy storage manufacturers. In 2021, only leading manufacturers have launched new products based on liquid cooling systems.

In 2023, liquid cooling will basically be the standard configuration for new energy storage products. Many new manufacturers, the first energy storage product comes with a liquid cooling system.

The new products of various manufacturers not only mark the reduction of energy consumption brought by the liquid cooling system, the improvement of battery life, and the reduction of floor space.

A core temperature control performance indicator of the liquid cooling system will also be marked: the temperature difference control range of the battery pack. The industry generally keeps it within 3°C, and some manufacturers claim that it can be kept within 2.5°C or even 2°C.

Compared with new products with standard liquid cooling systems, the process of liquid cooling replacing air cooling in reality is much slower, and air cooling still occupies a large part of the market.

Liquid cooling is also more expensive than air cooling, currently 3-4 cents per watt-hour. In the world, some customers have clearly proposed to be equipped with a liquid cooling system.

However, in China, customers pay more attention to the initial investment cost of the energy storage market, so the pace of replacing air cooling with liquid cooling may not be so fast.

Energy storage cells have entered the 300ah era

Larger capacity batteries are a development trend of energy storage. From the early 50-100Ah battery products to the 280Ah that dominated the market last year.

Larger capacity batteries will have higher energy density and have many advantages in terms of cost , can reduce the footprint and system accessories. At the same time, it is also beneficial to the consistency and optimal control of the system.

Since the second half of last year, many manufacturers have launched energy storage cell exceeding 300Ah. By this year’s ESIE, almost all energy storage products exhibited by energy storage manufacturers exceeded 300Ah. The specific specifications of each company are not uniform. Among the 300Ah-level batteries, Great power’s 320Ah may be the largest.

In addition, the 560Ah ultra-large capacity energy storage battery cell LF560K of EVE was released on October 20 last year.Construction on the 60GWh project in Jingzhou, Hubei Province, also began this year, and it is anticipated to go into production by the end of the following year. This exhibition EVE LF560K battery is also on display.

Each company has upgraded from 280Ah to 300Ah and above, and the size has basically remained the same, mainly by increasing the energy density. According to information feedback from equipment manufacturers, after April this year, energy storage cells with a capacity of more than 300Ah have been mass-produced one after another.

PCS manufacturers are also ready. At this year’s ESIE, a PCS manufacturer debuted a 1520V, 2MW energy storage PCS, which is adapted to large batteries above 300Ah.

It is foreseeable that cells above 300Ah will gradually replace 280Ah cells.

The battery cycle life exceeds 10000 times

Improving the cycle life of lithium batteries is a key to reducing the levelized cost of storage, and it is also the development trend of energy storage cells.

In June last year, a battery leader announced that its energy storage cells had passed 12,000 cycle life tests, and 12,000 cycles had become the benchmark. This year’s ESIE announced that all energy storage cell products had achieved 12,000 cycles.

The battery cell breaks through 10,000 cycle life, thanks to the development of lithium supplement technology.

A technical expert of a leading energy storage battery cell said that 8000-10000 times is the limit of the cycle life of lithium batteries, and the breakthrough of 10000 times is achieved through lithium supplementation.

In addition, the current cycle life of energy storage cells is generally 6000-8000 times, and the cycle life of 12000 times is only achieved in the laboratory, and it has yet to be verified in specific projects.

The director of a research institute of a leading energy storage enterprise said that in the past, the cycle life of cells was actually 6,000 times, but now the new battery cells can basically reach more than 8,000 cycles.

Exclusive designs for different application scenarios

Not only energy storage, but also in the wind power and photovoltaic industries, exclusive design for different application scenarios is the development trend of the industry.

In the past, the energy storage market was small, and manufacturers had no incentive to make exclusive designs for different scenarios. However, with the explosive growth of the market, exclusive designs for different scenarios have become a trend.

In fact, the use scenarios of energy storage on the power supply side, grid side, and user side are very different, and there are even big differences between the industrial and commercial and household use scenarios on the user side.

In the past, the energy storage power station on the power supply side was built to obtain resources, which is reflected in the cost and low utilization rate.

With the development of shared energy storage, both the energy storage on the power source side and the energy storage on the grid side will serve the grid and be mobilized by the grid.

As a result, the use scenarios of power-side and grid-side energy storage power stations converge, and the industry gradually merges them into the source-grid side market.

At present, when mainstream manufacturers develop products, they often release energy storage products for different application scenarios of source-grid side energy storage, industrial and commercial energy storage, and home energy storage.

Manufacturers from across the wind power industry also consider application in different regions. For example, challenges in special environments such as coastal areas, sandstorms, high humidity, and high and low temperatures. Corresponding anti-corrosion, high and low temperature designs, which have already been applied in fan design.

It is worth mentioning that the energy storage company under the renewable energy developer has gone a step further and further differentiated the application scenarios.

An industry professional said that energy storage can be divided into high-rate charge and discharge and low-rate charge and discharge. The first typical scenario is primary frequency modulation, and the second typical scenario is peak shaving.

A 0.5C lithium iron phosphate system can be used for low-rate charging and discharging, and a supercapacitor and lithium titanate system are more suitable for high-rate scenarios.

Energy storage smart transactions

In the energy storage industry, many renewable energy companies have crossed borders. In this ESIE, most manufacturers regard the energy storage system as a kind of equipment.

However, some manufacturers from across the wind power industry have put forward the concept of smart trading, emphasizing that the essence of energy storage is trading, and energy storage that can trade represents the future.

The transaction strategy is formed through the three-party data in the cloud, including the production data of the wind power, photovoltaic and energy storage equipment status connected to the regional centralized control monitoring, and the predicted power generation of renewable energy.

Develop smart trading terminals.According to load forecasting, power generation forecasting and grid equipment status, electricity price forecasting and transaction guidance are carried out.

It is the general trend to build a power market mechanism that is conducive to fully utilizing the value of energy storage. In the near future, energy storage needs to create value through transactions.

Smart transactions supported by sufficient data are more conducive to achieving optimal transactions and creating maximum value.

At present, manufacturers that cross-border in the wind power industry are at the forefront.