Renewable energy is not always green

In recent years, there have been significant steps made away from fossil fuels and towards a sustainable future. According to a new report by the International Renewable Energy Agency (IRENA), unsubsidised renewable energy is now most frequently the cheapest source of energy generation. Since the early 2000’s IRENA has reported that the worldwide weighted average cost of electricity from solar power concentration fell by 26%, that of bioenergy, solar photovoltaics, geothermal, onshore, as well as offshore wind, fell by 14%, and hydropower by 12%. Data from the renewable global status report shows that today over one fifth of global electrical power production is now generated from renewables. However, renewables desperately need safe and cheap storage solutions it they are to be a viable, stable source of energy.

 

That is where batteries, which are devices that store electricity as chemical energy, fit in. Lithium-ion batteries, used in mobile phones and Tesla electric cars, are currently the dominant storage technology and are being installed in electricity grids to manage surging supplies of renewable energy. Elon Musk, Tesla’s chief executive, has said he expects the company’s energy business — including the supply of solar and huge lithium-ion batteries for the grid — to be as big as its car business in the long term. The advantage of lithium-ion batteries is that they can be placed anywhere and can provide power to the grid very quickly which is essential if renewable energy is to fully replace fossil-fuelled power plants. At the moment, gas-fired power plants bridge the gap from renewables to provide stable supplies of energy for longer than current batteries can.

 

However, lithium is expensive, and its supply chain is unstable. Demand for lithium is increasing exponentially, with the price doubling between 2016 and 2018. According to consultancy firm, Cairn Energy Research Advisors, the lithium-ion industry is expected to grow from 100 gigawatt hours (GWh) of annual production in 2017, to almost 800 GWhs in 2027. The mining of lithium is causing huge environmental problems across the globe from South America to Tibet. These problems include water shortages, desertification, and toxic chemical pollution of the water supply. ‘Like any mining process, it is invasive, it scars the landscape, it destroys the water table, and it pollutes the earth and the local wells’ said Guillermo Gonzalez, a lithium battery expert from the University of Chile, in a 2009 interview. Lithium-ion batteries are also dangerous, made evident by the 33 fires at installations in South Korea between 2017 and 2018 alone. There have also been more recent incidents in the UK and US, and so large-scale use of lithium batteries in city centres is not currently an option.

 

There are various companies and teams working on cheaper, longer-duration storage technologies but most are not yet cost effective. Part of the UK government’s green industrial revolution launched last week is a 1 billion GDP energy innovation fund to help commercialise new low-carbon technologies. These include a liquid air battery being built by Highview Power outside Manchester. The US Invinity Energy Systems has successfully produced large-scale batteries which use vanadium – a safer and more environmentally friendly metal. Ambri has also developed a liquid metal battery that uses calcium and antimony, which has been backed from its inception by Bill Gates. Ambri’s battery aims to store energy for longer than six hours and its CEO, Mr Sadoway believes that its cost can go below 150 USD kilowatt-hour when it is deployed at scale, which would make it cheaper than current lithium-ion systems. In addition, at the University of Birmingham, battery research is being funded by the government’s 246 million GDP Faraday Challenge to find new ways of recycling lithium-ion. Furthermore, hydrogen, which is produced through the electrolysis of water using electricity, could emerge as a competitive solution for storing energy for longer periods of time. Hydrogen can be stored in underground caverns or depleted oil and gas fields. It is clear huge progress is being made in this sector and there are many fast developing companies and innovative technologies to keep an eye on over the next few years.

 

Ultimately, the energy storage sector for renewable energy is going to hugely expand over the next decade. Unfortunately, the lithium and lithium-ion battery market are likely to grow and profit alongside it. This form of energy storage is not currently sustainable, and as consumers and governments become more aware of the environmental impact their ‘green’ energy solutions have, it seems likely we will need to adopt more innovative solutions fix the world’s energy crisis.

 

By Olivia Pepper

Sector Head: Sophia Li

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