Some experts say that a cleaner future will mean focusing on ever-larger lithium-ion batteries. Others argue that green hydrogen is better – as in a hydrogen refuelling station, sitting by the road in the Orkney Islands, an archipelago off the north-east coast of Scotland.
And then there are those placing their bets not on chemistry, but the limitless force that surrounds us all: gravity.
“What goes up, must come down” – this is the immutable Newtonian logic underpinning gravity batteries. This new field of energy storage technology is remarkably simple in principle. When green energy is plentiful, use it to haul a colossal weight to a predetermined height. When renewables are limited, release the load, powering a generator with the downward gravitational pull.
Gravitricity, an Edinburgh-based green engineering start-up, successfully trialled a gravity battery prototype tower above ground, and is now looking to sink its own purpose built shafts using disused deep mine shafts.
Southern Switzerland has a gravity battery space prototype from Energy Vault.
Innovative experiments
The 130-square-foot two-story Solar Greenhouse is at Valldaura. The team of students and researchers from the Institute for Advanced Architecture of Catalina (IAAC) designed a prototype that could be used in both rural and urban areas to generate both energy and produce food without emitting greenhouse gases.
What about power being generated from pond scum? Researchers from the University of Cambridge have successfully kept a computer running from blue-green algae for 6 months. Read more
The South Koreans designed a 20mile long bicycle lane, in the middle of a highway covered with a solar panel roof. And the Dutch invented The solar bike path. Located in one of the busy suburbs of Amsterdam, It covers a modest stretch of 70m long and 3.5m in width. The path is made of concrete slabs with a layer of crystalline silicon solar cells and covered with strong protective translucent tempered glass, which allows the light to penetrate through.
Primary energy from clean sources
In 2020 renewable energy sources included hydropower, solar, wind, geothermal, bioenergy, wave and tidal. Our World in Data website has different interactive maps showing this worldwide distribution.
Since the industrial revolution, about half of the UK’s slag – a stony by-product of making iron and steel – has been used as a construction material. But the other half is an unseen and unused potential resource, with around 180 million tonnes.
As an alkaline material, slag can react with CO2 in the air and lock it away in solid minerals, offering a long-term form of carbon storage.
Carbon capture and storage (CCS) involves capturing, transporting and storing greenhouse gas emissions from fossil fuel power stations, energy intensive industries, and gas fields by injecting the captured greenhouse gases back into the ground.
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