What makes perfect sense to one person somewhere can seem totally bizarre to another elsewhere. The following list explains some niche sources of energy and the rationale behind them, giving credit to ingenuity whilst also raising questions.

Jellyfish protein-powered solar panels

This power source foregoes the need for expansive and geographically pinpointed materials like titanium dioxide to build PV panels by using the naturally assembled green fluorescent proteins (GFP) found in certain types of jellyfish. The current performance of these PV panels is well below standard, but GFP is continuing to be developed as a PV component because it incorporates a renewable resource – some sacrificial jellyfish – into PV manufacturing instead of using limited and costly resources.

GFP may be renewable but not vegetarian. Attempts to clone the gene would make it so, whilst streamlining the process and making production possible without the need for a jellyfish farm nearby.

Floating solar panels

This is a variation on the placement of PV panels. As we’ve seen in other examples, panels are an adaptable unit of power production: fitting on different roofs, as foldable phone chargers for camping weekends, and integrated onto farms (known as agrivoltaics).

‘Floatovoltaics’ sit atop bodies of water, symbiotically reducing evaporation while remaining at an optimal temperature by keeping cool in the water. A similar strategy was used in an LA reservoir where black shade balls were floated on the water to protect it from sunlight. Floatovoltaics would instead harness that sunlight.

‘Exploding’ lakes

This is a geographically specific method that relies on detecting stored gases deep within large lakes. The only standout case is Rwanda’s Lake Kivu, where a deposit of liquefied methane gas was detected. This gas is stored under the pressure of the water’s weight but is at risk of ‘erupting’ should the water be disturbed or water levels drop and the pressure relieved. The main risk of a limnic eruption is the release of a large cloud of gas capable of asphyxiating people and wildlife nearby, or even exploding.

A strategy to avoid an eruption is to harness the gas to power generators. In an operation similar to oil drilling, pipes extract the high-density methane liquid mixture to be distilled into usable gas. In context, it could be considered ‘clean energy’ given the harm it is alleviating.

Ultimately, the process’ main goal is to avoid disaster rather than purely produce energy, but it could be used as a model for tackling similar threats.

Kinetic tiles

Kinetic tiles generate power each time they are stepped on. Thin, slick tiles dip under the weight of a step, and that small, single moment can generate 7 watts. Each pad costs £279.00 before installation.

However, energy production scales up fast in high-footfall areas, accumulating huge energy savings from a previously unharnessed source:

• On average, approximately 60,000 people cross Tokyo’s iconic Shibuya crossing each hour.

• It takes someone with an average stride 55.8 steps to cross the average crossing distance.

(55.8 × 60,000) × 7 watts = 23,436,000 watts, or 23,436 kW.
This average hourly energy production could charge 3,255 EVs on a Type 2 charger – the equivalent of £2,714.00 of energy costs per hour.

It would take ~7,037 of Pavegen’s 45 cm × 60 cm tiles to cover the entire crossing, costing ~£1,963,323.00. The energy-saving figures suggest a payback time of 4.3 days! However, this does not factor in installation costs nor the disruption caused to the busy landmark. It does demonstrate its feasibility in popular urban areas. Energy can be immediately used in streetlights and traffic lights, requiring no storage but only simple optimisation.

Their gapless design seems resistant to cigarette butts, bottle caps, and other city rubbish getting lodged between them. I do not know what they are like to walk on – people may object to sinking into the ground and having their walking pace slowed.
The appearance of the tiles would also change the urban landscape. What blends well into Tokyo or Singapore might not be so popular in Rome or Athens.

Kinetic roads

Sibling to kinetic tiles, kinetic roads capture energy from vehicles by having their weight put pressure on piezoelectric materials, which have the unique property of generating a charge when under weighted stress – at a rough average of 118 watts per vehicle.

Kinetic roads have greater challenges to address than pedestrian-suited tiles. They must integrate into a robust road surface and take longer to install with greater disruption. Installation and energy production are at odds with one another, as the busier the road network, the less approachable it is to install.
It is a fascinating concept but not yet scalable.

Wind Trees

Blending form and function, machine and sculpture, Wind Trees are wind turbines in the form of trees with shell-shaped spinning leaves and branches of solar panels. Wind Trees, along with the Wind Bush and Wind Palm, are suited to integration into urban areas, representing innovation and regeneration.

Their small, silent movements generate 49.3 kWh per day, providing the bulk of a household’s (including an EV) energy needs once the ~£43,363.00 cost is accounted for.

This is a much more scalable technology, adaptable to different urban environments and able to rely on existing energy storage systems used by rooftop solar installations.

Solar wind energy

A bit out there in more ways than one, this theoretical energy source seeks to harness charged particles flowing outwards from the sun. The extreme heat radiating from the sun charges particles with enough energy to escape its gravitational pull. Japan’s interplanetary IKAROS already uses this technology – the big challenge is bringing the energy back to Earth. If realised at its full potential, solar wind energy could provide the planet with 1 billion gigawatts of electricity, which is 100 billion times more power than the planet currently consumes.

With this in mind, the name of Japan’s spacecraft is indeed worthy.