The UK cost of living crisis, illustrated by alarmingly high rises in fuel and energy prices, has driven home more starkly than ever before the importance of energy security for European states. The disproportionate geographical control of fossilised gas and oil reserves as well as disruption to the global supply chain has led to huge volatility within the fossil fuel energy market in recent months. The renewable energy sector has however remained much more stable. This has led many people, businesses and governments to turn their attention more closely to this fast-developing and ever-innovating market.
When most people think of renewable energy they think solar panels and wind turbines; high-costs, low energy yields and cumbersome aesthetics. While high-costs and low-yields compared to fossil fuels may have been true not so long ago recent innovations have changed the landscape, literally and figuratively, with renewable energy becoming ever more cost-competitive, efficient and necessary for energy security. In this article we will explore some of the innovations around energy storage, solar, tidal, kinetic and thermal energy as well as renewable cost reduction and scalability trends as states work towards reaching net zero.
There is plenty of untapped potential in solar energy generation with the surface of the earth receiving solar radiation energy at an average of 81,000 terrawatt, exceeding global energy demand by a factor of 5,000. A recent innovation in this field is 3D printed energy harvesting trees, artificial trees which have solar panel cell ‘leaves’ that harvest solar, wind and temperature energy. The trunks of the trees are made of wood-based biocomposites which can be mass produced and easily replicated through 3D printing. Currently the use of these trees is small-scale powering simple household appliances but with the capability to build entire forests of these trees the energy harvesting potential is much larger and more efficient than traditional solar panel farms.
Perhaps the most exciting and innovative development in solar energy harvesting comes from the Phillipines through AuREUS, a translucent material made from waste crops that can clad highly developed urban skyscrapers and buildings to absorb UV light and convert it into electricity. UV light is typically too powerful to directly channel into usable energy so the AuREUS material first converts the UV into visible light before then storing that as electricity. This product won the James Dyson award for sustainability in 2020 and its application has many advantages over traditional solar panels.
Current solar panels will only work while directly facing the sun and in clear weather but as AuREUS is absorbing UV light which pierces clouds it can work in overcast weather and doesn’t have to directly face the sun as UV radiation reflects off surfaces and into the material. It also has safety benefit implications as windows currently reflect UV radiation away from buildings and onto the street meaning that pedestrians are even more exposed, but the AuREUS material absorbs the radiation making the inside and outside of buildings safer.
Another big issue with traditional solar panel farms is the amount of space they require, and the land costs associated with that much space. The AuREUS material can clad buildings like skyscrapers in highly developed urban areas helping to power these cities without requiring any additional space. The inventor Carvey Ehren Maigue has also hinted at future applications of making a chassis for vehicles from the AuREUS material for solar powered transport, further embedding sustainability into modern lifestyle needs.
Waste to energy
Moving away from solar we look at an exciting project in Denmark’s Capital Copenhagen with Copenhill which opened in 2019. This is a large waste-to-energy incinerator which powers 30,000 homes and heats 72,000 more and due to the very vertical nature of the design of the building it has a commercial dry slope built onto the roof. The commercial space includes ski/snowboarding lessons and sessions, the world’s largest climbing wall at 85 metres, bars, restaurants and a large range of activities and events like live music and archery tag. This combination of sustainable energy generation infrastructure and commercial space gives a good indication at the potential landscape of future green cities.
Tidal is an as yet mostly overlooked potential for renewable energy generation despite it having clear advantages over other forms like wind. A company in Scotland called Nova is developing and manufacturing tidal turbines which are already powering homes and businesses in Shetland, Scotland and Nova Scotia, Canada. Water is 830 times denser than wind so tidal turbines can generate the same amount of energy as wind across a much smaller space, they also have no visual or navigational impact as they are underwater. With a similar lifespan to wind turbines and the potential to generate more energy over a smaller space tidal should be considered more closely as a viable renewable energy source.
Thermal and kinetic
Staying in Scotland SW23, a nightclub in Glasgow, is trialling an innovative new form of energy – dance energy. Using a system dubbed BODYHEAT the thermal energy generated by revellers on the dancefloor will be captured, transferred to waters and piped to underground boreholes to be stored in rocks which act like heat batteries and used to heat or cool parts of the club when needed. The system will eliminate the club’s need for gas boilers and the owner says the energy generated on the dancefloor will be more than enough to heat the club even in the coldest winters.
Sticking with public power some high-footfall venues such as Heathrow and Dubai airport are already harnessing kinetic energy to help power their operations more sustainably. Specifically the kinetic power of footsteps is transferred into electricity and quite literally keeps the lights on as thousands of people a day step on the energy converting tiles.
Despite all these developments and innovations in clean renewable energy one of the biggest driving factors for which type of energy to generate is always going to be cost. From 2010 – 2019 the cost of solar power has fallen 80% and from 2020-2022 the cost of solar has fallen a further 13%, onshore wind 15% and offshore wind 13%. Over the same period from 2020-2022 fossil gas has risen over 600% in Europe largely due to disruption to the supply chain following the war in Ukraine. This has made solar power cost-competitive when compared to fossil gas and the renewable energy infrastructure added in 2021 (about half of total global renewable infrastructure) will result in savings of around £45 billion globally in 2022 and reduce costs by £4.71 billion annually over the next 25-30 years.
Generating the energy renewably and making the cost-competitive case for renewables over fossil fuels is still only part of the picture as to have a reliable, resilient, long-term and large-scale energy system there will always be a need for energy storage infrastructure. This is typically in the form of lithium-ion batteries although some hydroelectric and hydrokinetic power plants can also be used as backup power during peak periods. The biggest issue with a reliance on lithium-ion (Li-on) batteries is the cost and availability of the raw materials. Some work is already taking place on lithium-sulphur based batteries with the material Boron Carbide made from hemp making them much more sustainable than Li-on batteries which rely on heavy metals like nickel and cobalt. They also outperform Li-on batteries on energy density, safety, cost and recyclability.
To sum up
With the focus of European states on energy security following the disruption to the fossil fuel market there is clearly both a need and a desire for more renewable energy in Europe and globally. The trends and innovations explored in this article shed some light on the great work that is taking place to make renewable energy a reality now, and what the future of cities and renewable energy generation and storage might look like.