What is the environmental impact of BESS? Thorough explanation from merits and demerits to next-generation technology

BESS (battery energy storage system) is essential for the spread of renewable energy. While it is expected to be a trump card for building a clean future, not much is known about the environmental and social impacts behind it. In this article, I will shed light on both aspects of “light” and “shadow” that BESS has, and explain specialized information in an easy-to-understand manner for anyone, from its merits and demerits to the latest technology to overcome issues.

Why is BESS (storage battery) attracting attention now? The trump card for achieving carbon neutrality

As the world takes a major turn towards achieving carbon neutrality, the introduction of renewable energy (renewable energy) such as solar and wind power is progressing rapidly. However, renewable energy has a major weakness that “it is affected by the weather and the power supply becomes unstable.” The key technology to solve this problem is BESS, or large-scale energy storage systems.

Weaknesses of “renewable energy” solved by BESS

Electricity generated by solar power generation during the daytime when the sun is shining is stored in BESS and used at night. Electricity generated by wind power generation is stored when the wind is strong, and used when the wind stops. Thus, BESS acts as an “adjustment valve” that adjusts the balance between electricity supply and demand. This will pave the way for utilizing renewable energy, which until now was difficult to introduce due to instability, as the main force in power grids.

Contributes to stabilizing power grids and prevents large-scale power outages

The role of BESS is not only to absorb fluctuations in renewable energy output. By releasing (discharging) stored power when demand for electricity rapidly increases, the stability of the entire power grid is maintained and the risk of large-scale power outages is reduced. As a “huge buffer” for the power grid, so to speak, it supports the power infrastructure essential to our lives behind the scenes.

[Light] 3 major benefits that BESS brings to the environment

What specific environmental benefits will the spread of BESS bring to our society? Here, let's take a look at 3 typical points.

Advantage 1: Accelerate the adoption of renewable energy

As mentioned above, by compensating for the instability of renewable energy, BESS dramatically increases the amount that can be introduced. Even in Japan, “output control,” where acceptance of renewable energy is restricted due to power system restrictions, has become an issue, but demonstration tests of BESS are underway in various places, and significant results have been achieved in avoiding output control.

Advantage 2: Reduce fossil fuel use and reduce CO2 emissions

Most thermal power plants that operate during peak electricity demand are inefficient power generation facilities with high fuel costs and high CO2 emissions. With BESS, it is possible to minimize the operation of such thermal power plants by charging during times when there is relatively excess power and discharging during peak periods. This greatly contributes to reducing CO2 emissions throughout the power system.

Advantage 3: Future power grids pioneered by “Grid Forming” technology

It's a bit technical, but BESS, which is equipped with a new technology called “grid forming (grid forming),” is attracting attention. This is a technology where BESS itself plays a role like a “control tower” that maintains the stability (frequency and voltage) of the power grid. With this technology, it is expected that it will be possible to maintain overall system stability even if most of the generators connected to the power grid become renewable energy in the future.

[Shadow] Environmental and social disadvantages of BESS that cannot be ignored

While BESS has brilliant benefits, we must also look at the serious challenges inherent in its entire life cycle: the process from raw material extraction to manufacturing and disposal.

What is happening at the raw material mining site?

Rare metals such as lithium, cobalt, and nickel are essential for lithium-ion batteries, which are the main batteries of BESS. However, the extraction of these resources can take a huge toll on the global environment and the human rights of local people.

Lithium mining: “white oil” threatening South America's water resources

In the South American “lithium triangle” (salt lake area spanning Chile, Argentina, and Bolivia), which is a global production area for lithium, the method of extracting lithium by evaporating large amounts of water is the mainstream. This method not only depletes precious water resources in arid regions and destroys ecosystems, but also threatens the livelihoods of indigenous peoples living there.

Cobalt Mining: An Inconvenient Truth About Human Rights and Health Hazards in Congo

Poor and dangerous working environments have become a serious problem in the African Democratic Republic of Congo, which produces about 70% of cobalt. According to reports from international human rights NGOs, even 7-year-old children mine ore by hand, and many workers inhale toxic dust without protective equipment, suffering from fatal respiratory diseases and dermatitis. Furthermore, it has been revealed that mine effluents pollute rivers and soil, causing serious health damage to the reproductive function of local residents, especially women.

CO2 emissions and energy consumption during manufacturing

Battery manufacturing, particularly in the process of drying electrodes, consumes a lot of energy and emits CO2. When assessed throughout the life cycle (LCA: Life Cycle Assessment), electric vehicles (EVs) do not emit CO2 when driving, but there are also indications that emissions at the battery manufacturing stage exceed gasoline cars. Similarly, how to reduce environmental impact during manufacturing is a major issue for BESS.

The reality of a “recycling rate of 5%.” Disposal and reuse barriers

Used lithium-ion batteries can cause environmental pollution if not treated properly, but recycling them is not easy, both technically and cost-wise. There is also shocking data that the global recycling rate as of 2022 is only about 5%. In Europe and America, even a collection scheme for used batteries has not been sufficiently established, and the current situation is that many batteries are “missing.”

Which storage batteries are environmentally friendly? Compare characteristics by battery type

Lithium-ion batteries are not the only batteries used in BESS. Here, let's compare the environmental advantages and disadvantages of the four typical battery types.

battery type

lithium ion battery

・High energy density
・Long life

・Environment for raw material extraction
・Human rights risks
・Fire risk due to heat runaway

lead-acid battery

・Recycling technology established (rate of 90% or more)
・Low cost

・Contains harmful substances such as lead and sulfuric acid
・The lifespan is short

NAS battery

・Rich in resources (sodium, sulfur)
・Long life, large capacity

・It is necessary to operate at a high temperature of 300℃
・Fire risk due to sodium

redox flow battery

・Can be used semi-permanently by replacing the electrolyte
・The risk of ignition is extremely low

・Low energy density (becomes larger)
・Rare vanadium may be used

Challenge to solve problems. Global trends towards sustainable BESS

While there are serious issues, strong movements are also emerging around the world to overcome them. Let's take a look at the front line from the three aspects of regulation, technological innovation, and corporate initiatives.

The world moves. EU 'battery rules' will change supply chains

In 2023, the “EU Battery Regulation” came into effect in Europe. It's a groundbreaking law mandating sustainability throughout the battery life cycle. Specifically, it includes displaying CO2 emissions, setting minimum standards for the utilization rate of recycled materials, and human rights and environmental due diligence (obligation for companies to identify and address risks in the supply chain). As a result, companies are being pressured to prove “where, who made, and how” their products, and it is expected that transparency and sustainability of the entire supply chain will accelerate.

Technological innovation opens up the future

In order to solve environmental and social issues from the ground up, researchers and companies around the world are struggling to develop next-generation batteries and recycling technology.

to rare metals. Expectations for “sodium-ion batteries”

Practical application of “sodium ion batteries,” which use sodium (the main component of salt), which is abundant on Earth without using scarce and high-geopolitical risk resources such as cobalt and lithium, is imminent. Although the energy density is inferior to lithium-ion batteries, it has the major advantage of being low cost and without resource risk, and it is expected that it will spread as a stationary BESS.

CO2 emissions have also been reduced by 47%. The possibility of “direct recycling”

Conventional recycling methods (such as dry smelting, where metals are extracted by melting at high temperatures) consume a lot of energy and have the problem of emitting CO2. In response to this, a new technology called “direct recycling,” which directly regenerates cathode materials etc. from used batteries, is attracting attention. Research by Japan's NEDO (New Energy and Industrial Technology Development Organization) shows that by using this technology, CO2 emissions can be reduced by as much as 47% while drastically improving resource recovery rates.

Corporate Initiatives: Responsible Minerals Procurement and Traceability

An increasing number of companies are participating in the international framework “RMI (Responsible Minerals Initiative),” which aims to procure minerals in a way that takes human rights and the environment into consideration. In addition, there is also a movement to ensure “traceability,” which makes it possible to track all processes from when minerals are mined until they become products by utilizing technology such as blockchain, etc., and efforts to eliminate human rights violations and environmental damage from the supply chain are spreading.

Understanding BESS's environmental issues and choosing the future

There is no doubt that BESS is a powerful tool for achieving a carbon-neutral society. However, in order to enjoy the benefits to the fullest, it is impossible to turn a blind eye to the environmental impact and human rights issues behind manufacturing.

The first thing we consumers can do is take an interest in these facts. Also, it is important to require companies to create more transparent and sustainable products.

By combining strengthened regulations such as the EU battery regulations, technological innovations such as sodium-ion batteries, and corporate awareness reforms, BESS can become the core of a truly clean and sustainable energy system. Choosing that future depends on the choices each of us makes.

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