Monday, 7 August 2017

Finding new ways to power the world - kinetic energy

Potential power sources rushing to work (via Flickr, by Scott Robinson)

An energy we rarely think about is the kinetic energy we release while moving around. This energy, and its potential for electricity production has been noticed by scientists and engineers. They have devised, and are already beginning to implement intriguing new methods of harvesting the energy of human movement. Walking, jumping and dancing are all starting to contribute to clean energy.

PowerWalk by Bionic Power in action (via Bionic Power)PowerWalk by Bionic Power in action (via Bionic Power)
The first kinetic harvester on this list is the PowerWalk from Bionic Power, a device that uses walking movement to recharge batteries. It fits onto the user's legs and adjusts its tension based on the speed of walking and the terrain. Additionally, this device "reduces muscle fatigue during downhill walking, easing metabolic effort and reducing potential for injury" (Bionic Power website). The PowerWalk is scheduled to begin military trials this year.

Partygoers lighting up the Sustainable Dance Floor (via Energy Floors) The empty floor still lit up (via Energy Floors)
But it's not all serious business, and innovative energy sources are great for days off too. That's exactly what the Sustainable Dance Floor by Energy Floors is all about. This floor is made up of individual tiles, each containing an electromechanical system that converts the pressure of the weight applied to it (the movement of dancing people) into electricity for LED lights. The Sustainable Dance Floor creates an interactive experience for clubgoers, and can be used for specific DJ-controlled  effects, such as an "energy battle" (electricity generating contest) in the audience.

A grid of Pavegen tiles (via Pavegen) A single Pavegen tile (via Pavegen)

Producing energy through movement doesn't have to be obvious or exceptional. In fact, a piezoelectric floor can blend into everyday life seamlessly. This has been proven time and again by Pavegen, a London-based company whose tiles inconspicuously harvest energy at over 150 sites worldwide. Much like the Sustainable Dance Floor, these tiles are activated when stepped on by a pedestrian, and collect energy (primarily) to contribute to LED lighting. Instead of illuminating a party, the Pavegen tiles often power streetlights, and even USB ports for charging mobile devices.

Pavegen tiles at Dupont Circle, Washington (via Pavegen)

While not yet widely used, kinetic energy from human movement presents amazing potential, and is already becoming an applicable alternative.

Friday, 4 August 2017

Designing ecosystems to clean wastewater

Untreated wastewater is devastating to the environment. Luckily, sewage can be rehabilitated into environmentally safe and reusable water through a multi-step process. This often involves pools of murky water and thick muddy substances stewing in large vats, but that isn't the only way.

Wastewater pipe via Water Technology Sewage Water Re-Treatment Plant (via Acroama)

Conventionally getting rid of sludge (concentrated wastewater that has completed the first stage of treatment) involves mixing it with a bacteria and protozoa cocktail called the biological floc. This mixture is then aerated (supplied with oxygen) which enables the bacteria to process the sludge.

Schematic of wastewater flow through wetland
© United Nations Environment Programme 2003
An innovative approach to the wastewater problem is to create a wetland ecosystem where naturally occurring bacteria and fungi digest and eliminate the pollutants. Not only are these wetland environments efficient and effective as a water cleaning method, they are also more self-sustaining, with the roots of the plants providing aeration to the bacteria in the water.

Great Blue Heron via Mark Ahrens Photography
Arcata Marsh and Wildlife Sanctuary (via Humboldt State University)

One of the most successful examples of this is the Arcata Marsh and Wildlife Sanctuary. This interconnected complex of ponds, wetlands and marshes cleans sewage runoff in the most elegant and appealing way imaginable. In fact the water treatment facility has become a tourist attraction famous for its wildlife diversity and is now a great place to spot a wide variety of migratory birds.

Marystown Pilot Municipal Sewage Treatment Project via Abydoz Environmental Inc Holyrood Wastewater Treatment Facility Abydoz Environmental Inc.

But wetlands don't have to be so grand and expansive. Smaller water treatment ecosystems can be created on demand, and can still be effective in combating water pollution. For example, companies like Abydoz Environmental Inc. , WetlandsPacific Corp. and many others around the world have been creating wetlands that fit to specific environments, needs and locations, providing water treatment to communities, companies and even individual houses.

Using ecosystems to combat pollution is amazing, and one can only hope that we will continue to discover and implement sustainable, environmentally supporting methods to mitigate our impact on the world.