Peculiar power sources
With an increasing awareness of our finite fuel resources, researchers are investigating how we can extract energy from some of the most unlikely sources
Exploding lakes
So-called ‘exploding lakes’ contain massive reservoirs of methane and CO2. Under normal conditions the water’s density keeps the gasses trapped below, but when a lake’s temperature (and therefore density) changes the gasses can violently erupt with a cloud of deadly, suffocating gasses called a limnic eruption. However, harnessing these dangerous substances could both save lives and provide power. The Kivuwatt project in Rwanda extracts methane from Lake Kivu and sends the gas via a pipeline to a power plant to generate electricity.
Body heat
Buildings can be heated efficiently by harnessing the body heat of crowds – particularly those in shopping centres and train stations. In Stockholm Central Station, Sweden, the body heat of around 250,000 passengers a day is used to heat a nearby office block. In the station’s ventilation system, heat exchangers transfer the thermal energy from the air to water in the pipes, which is then pumped to the neighbouring office’s heating system. Imagine hitting the dance floor to your favourite songs and knowing that while you were dancing you were helping to power homes? Club Watt in The Netherlands is doing just that by using floor vibrations to power the lights. The company Energy Floors have created tiles that contain an electromechanical system, transforming small vertical movements – when they’re stepped on – into a rotating movement, which drives a generator positioned below to produce electricity.
Poo power
It might sound gross, but this is one power supply that will never run out! When bacteria feed on faeces under anaerobic conditions they produce methane and carbon dioxide gas, which can be stored and used as fuel. Some companies even process human waste into a hygienic solid fuel that can be used as a replacement for coal.
Coffee grounds
Globally, over 2 billion cups of coffee are drunk each day. But rather than binning the leftover grounds, what if we could use them as fuel? Bio-bean are a UK company that have turned this idea into a business, collecting waste coffee grounds from businesses and turning them into various biofuels and biochemicals. By removing moisture from the grounds and compressing them into pellets, the company can create coffee ‘logs’ that customers can use instead of traditional wood on fires.
Jellyfish
Current technology limits the amount of energy we can collect and store from solar power, but scientists are now investigating how we can use ‘biosolar’ sources. Golden jellyfish host large amounts of algae-like organisms – which photosynthesise very efficiently – within their tissues. By harvesting the photosynthesising ‘reaction centres’ of these organisms scientists could create much more efficient biosolar panels.