The share of solar PV and wind in India’s electricity generation mix doubled between 2016 and 2018, from 4% to 8%. Image courtesy andreas160578 via Pixabay

Energy transition: opportunities and constraints

The energy transition is well underway, driven mostly by solar and wind power, electric vehicles and energy storage. The opportunities are tremendous, and progress has been faster than expected, thanks to technological breakthroughs and rapidly shrinking costs. This development raises surprising questions about the pace at which this transition is to be conducted.
 
^ The share of solar PV and wind in India’s electricity generation mix doubled between 2016 and 2018, from 4% to 8%. Image courtesy andreas160578 via Pixabay

Article By James Chater
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For instance, will new fossil power or nuclear stations, or new oil and gas projects, turn out to be white elephants? Has the internal combustion engine had its day, and how soon should it be phased out? When we think about how rapidly global warming is advancing, it seems that transition cannot happen soon enough. However, before we reach the renewable Promised Land, we need to address issues about the future availability, costs and the environmental fingerprint of special metals.

In a recent book David C. Fessler identified three factors that are driving energy transition in what he calls an “energy disruption triangle”: solar power, electric vehicles (EVs) and energy storage. The three are mutually self reinforcing: if EVs replace internal combustion engines, this will boost demand for electricity, which can be met only by developing renewables, especially solar and wind. These, in turn, can make headway only if energy can be stored, and storage relies a great deal on batteries; these run on lithium, a crucial material for both EVs and storage of renewable power.

Juxtaposed by challenges

The main issue that policymakers face is the speed with which they are to transition away from fossils towards renewables. Factors in that decision include energy demand (which depends on the economy); the environmental risks of continued fossil fuel dependence; and the rewards of embracing renewables (lower emissions, cleaner air, less risk of shortages).

However, these are juxtaposed by the challenges: scalability, lack of storage capacity, limitations of current battery technology and difficulties in obtaining key materials. In the USA and Europe, the lack of political will could be added as a crucial factor. Why are fossil fuel industries still receiving subsidies? Why is Europe subsidizing a new generation of LNG receiving stations? And climate scepticism in US politics is not helping matters, although in the USA the transition is by now unstoppable, and 22 states plus the District of Columbia have adopted greenhouse gas reduction targets. Natural gas, especially shale, is an important part of the US economy; however, several renewable energy research programmes and installation projects (mainly wind and solar) are underway, and electrical vehicle infrastructure is far advanced.

European Green Deal

In Europe, renewable energy has been developed rapidly, especially in Germany, Spain and the UK, as well as in smaller economies such as Portugal and Denmark. Earlier this year the EU unveiled its “green deal”, which aims to make the region carbon-free by 2050. This multi-pronged strategy will include not only installation projects but also reskilling, recycling, innovation, public transport, energy efficiency of buildings, biodiversity, tackling pollution and more. Some countries aim to exceed this target.

Part tourist attraction, part experimental wind power laboratory, the Windwheel is being built in Rotterdam, the Netherlands. It will incorporate rotating cabins, apartments, a hotel and a restaurant, and last but not least a silent, bladeless electrostatic wind turbine.
Part tourist attraction, part experimental wind power laboratory, the Windwheel is being built in Rotterdam, the Netherlands. It will incorporate rotating cabins, apartments, a hotel and a restaurant, and last but not least a silent, bladeless electrostatic wind turbine.

East Asia is the region where demand for power generation has been growing most strongly. In an effort to tackle its serious pollution problem, China is turning away from coal towards renewables, natural gas and electricity. The country is building the world’s largest wind farm at Gansu, with a planned capacity of 20GW.

India too is embracing renewable energy and the share of solar PV and wind in the country’s electricity generation mix doubled between 2016 and 2018, from 4% to 8%. India is host to world-scale solar projects, such as the Shakti Sthala, located in Pavagada in Karnataka’s Tumakuru district. Its 2,000MW can supply electricity to 700,000 homes. Several more are planned, mainly in the northern desert regions and the arid south.

Renewable power innovation

The sectors of solar and wind power are bristling with innovation. Several research projects exist to mitigate the drawbacks of wind power, especially noise and unsightly landscapes. Makani’s wind kite flies at high altitudes to harness stronger winds, and its tether conducts the harvested energy to the ground. Evdemon’s “wind harvester” can collect wind power for use in individual buildings. The Windwheel in Rotterdam will work by blowing positively charged water droplets into an electrical field to create a negative charge. WindPlus is working on a wind turbine that can be constructed on land before being floated out to sea.

With solar power, the most important innovation is probably the use of synthetic perovskites to boost the efficiency of solar PV cells. By adding perovskites to traditional silicon, manufacturers can capture a wider spectrum of solar ray frequencies. Unprecedented efficiencies of over 30% can be further raised with zirconium-doped transparent electrodes of the kind developed by Kaust.

Transport innovation

Manufacturers have gone to great lengths to create more efficient, less polluting internal combustion vehicles by introducing lighter materials such as stainless steel or alloyed steels. However, according to an article in Which?earlier this year, recent models have been gaining weight, and, after a period when CO2 emissions had been reduced, they are rising again; the worst offenders are said to be small petrol cars, large petrol hybrids and SUVs. In light of this, the IC vehicle seems to have had its day, unless designs improve quickly. However, they face increasingly stiff competition from electric vehicles.

EV manufacture has now gone mainstream: scarcely an auto maker exists who dares not venture into this field. However, EVs will remain indelibly associated with Elon Musk’s company Tesla. Electric vehicles were proposed in the early days of auto production, but the discovery of large amounts of petroleum in the USA led to the universal adoption of the IC engine. This changed when the first Toyota Prius hybrid car appeared on the market in 1997. Then in 2008 Tesla relaunched the EV with its landmark Roadster. This was followed by several other types catering for a wide range of demand and taste.

Surplus energy

But Tesla’s most important innovation may turn out to be the lithium-ion rechargeable battery on which its EVs run. Lithium is the key material used not only in car batteries but also in those of mobile phones, tablets and computers. Other materials used in EV lithium-ion batteries include cobalt, nickel, manganese and graphite (the last is likely to be phased out as it is hard to obtain).

The lithium-ion battery is also an important complement to renewable power generation, which relies on storage (and therefore on batteries) to tap into surplus energy during periods when the sun does not shine or the wind is stilled.

The EV is basically a computer and a battery array on wheels. It is simpler in design and far easier to maintain than an IC-driven vehicle. It is also less polluting; as for emissions, how you assess its performance depends on where the electricity comes from. If it is from fossil-fuelled power stations, nothing will be gained. But when zero-carbon carbon power generation has been achieved, EVs’ environmental footprint will be correspondingly slight. However, for EV use to expand, more electricity will be needed, and this can only come from renewables.

Materials hard to source

The issue of increased demand for lithium, both in EVs and energy storage, brings us to the most pressing issue concerning energy transition: the availability of the materials on which it depends. Some of the materials are hard to source, and even though “rare earths” are not all rare, the mining and extraction techniques used place a heavy burden on the environment.

Lithium itself is not very rare, but EV manufacture has ballooned to such an extent that its future development is likely to be constrained by production bottlenecks. Another drawback of lithium-ion batteries is that they have been known to explode when overheated. Several alternatives to lithium-ion have been proposed for batteries: aluminum-ion, sodium-sulphur, sodium-ion, gold nano-wires, graphene, zinc-air, hydrogen fuel cells, fluoride, magnesium, ammonia and so on, but for the moment there are no clear front-runners.

Research on the alternatives to lithium offer more than a glimmer of hope, as do efforts under way to make rare earth refining techniques more sustainable. Neodymium and dysprosium are two “rare earths” important for the superconducting magnets used in modern electronic goods and wind turbines.

Not only are these materials rare, but the refining process consumes large amounts of energy and is very polluting. As an alternative to leaching from bastnasite or monazite, eudialyte has been proposed as an alternative, more sustainable source. Researchers at the University of Pennsylvania have proposed a new approach for separating mixtures of rare earth metals by using a magnetic field to eliminate acidic waste.

Conclusion

Further research is vital if the best technologies for energy transition are to emerge. The economic repercussions of the Covid-19 virus are likely to be severe and the temptation to cut back will be great. Therefore, it is vital that we do not lose sight of the need for investments and funding to promote the energy transition – for instance DNV’s venture fund, announced this March.

References Fessler, David C., The Energy Disruption Triangle, Hoboken, NJ, Wiley, 2019; Porter, Adrian, “Why new cars’ emissions are even worse for climate change”, Which?, March 2020, 12-16; www.iea.org.
 

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