Battery Energy Storage Systems (BESS): role and sustainability ?

Battery energy storage systems (BESS) are becoming increasingly important as the world transitions to a more renewable energy future. BESS can store energy from solar and wind power plants, and then release it back to the grid when needed. This helps to smooth out fluctuations in power demand and supply, and can help to prevent blackouts and brownouts.

BESS can also be used to improve the efficiency of the power grid. For example, BESS can be used to store energy during off-peak hours when electricity prices are low, and then release it back to the grid during peak hours when prices are high. This can help to reduce the overall cost of electricity.

In addition, BESS can be used to provide other grid services, such as frequency regulation and voltage support. Frequency regulation is the process of keeping the frequency of the AC power grid within a safe range. Voltage support is the process of keeping the voltage of the AC power grid within a safe range.

The benefits of BESS have led to a rapid increase in their deployment in recent years. In 2022, the global market for BESS was worth $10 billion, and it is expected to grow to $40 billion by 2027. There is currently no single month without any announcement regarding a potential new largest batterie on earth.

Just to share some examples, the Energy Storage Facility at Moss Landing in California is currently one of the world’s largest online grid-scale battery. It was completed in 2021 to reach a total capacity of 400 MW/1,600 MWh, the equivalent of a combined cycle power plant during 4 hours. Here the purpose is clearly to face potential black-outs.

In Australia, one of the largest unit is in Victoria, near Geelong about 65 km from Melbourne. It is a grid-scale battery storage facility with a capacity of over 300 MW/450 MWh. It covers the size of a football stadium and can store enough energy to power over one million homes for at least 30 minutes. The VBB “Very Big Batterie” began operating on November 21st, 2021.

In Japan, the Buzen Substation BESS, designed and built by the Mitsubishi Electric Corporation is the world’s largest sodium-sulfur battery energy-storage system. It is installed at Buzen Substation in Buzen, Fukuoka Prefecture. It can provide 50MW of power during 3 hours.

The most common type of battery used in BESS is the lithium-ion battery. The batteries are known for their high energy density and long cycle life and they have one of the highest power densities of any commercial battery technology, approaching 300 watt-hours per kilogram (Wh/kg) compared to roughly 75 Wh/kg for alternative technologies.

According to the International Energy Agency (IEA), the global production of lithium-ion batteries in 2022 was 948 GWh. This is an increase of 75% from the previous year. Growth will go on within next decades.

The majority of lithium-ion battery production in 2022 was for electric vehicles (65% of the total, 617 GWh). The remaining (35%, 331 GWh) was mostly produced for energy storage systems and portable electronics.

To give an idea of how much we are speaking about, a typical lithium-ion battery contains about 7% lithium by weight. So, the 948 GWh of lithium-ion batteries produced in 2022 contained about 66,360 tons of lithium which represent the weight of more than 300 blue whales, quite a lot for a rare earth !

The future of BESS looks bright. As the cost of batteries continues to decline, BESS is becoming more and more economically viable. This is likely to lead to a rapid increase in the deployment of BESS in the coming years at a point where this technology may clearly compete with conventional power station to absorbe peak loads.

However, the impact on environment should not be underestimated. For example, lithium mining requires a lot of water. In some cases, it can take up to 500,000 liters of water to produce one ton of lithium. This puts tension on water resources, especially in arid regions where most of the lithium is coming from. For example, in the Atacama Desert in Chile, it is estimated to use up to 600,000 liters of water per ton of lithium produced which is a complete environmental disaster. A similar issue may occur in Asia Pacific as well.

Beside the water concern and the massive land degradation, the extraction and processing of lithium can also release air pollutants and toxic wastes, such as dust, sulfur dioxide and acids. These pollutants can contribute to respiratory problems and other health problems. A study by the University of Massachusetts Amherst found that the production of lithium-ion batteries can produce up to 200 kilograms of toxic waste per ton of battery produced.

The IEA projects that the global demand for lithium-ion batteries will continue to grow in the coming years, reaching 2,000 GWh by 2028. The energy transition and the massive use of BESS needs to be green to be sustainable. In all projects we are handling, it is absolutely required to have an holistic view on impact of our decisions. I do believe here that we should have a double approach:

First, as mentioned earlier, lithium mining can have a significant environmental impact. One way to reduce this impact is to use more sustainable sources of lithium.

Second, reuse and recycle lithium-ion batteries needs to be mandatory. Lithium-ion batteries can be reused and recycled, which can help to reduce the amount of waste produced. When batteries are recycled, the lithium can be extracted and used to make new batteries. As of today, Japan should be benchmarked.