8 green-tech innovations you need to know about

Milk is coming out of the fridge and into the wardrobe. In Germany alone, up to 1.9 million tons of milk is wasted each year. Anke Domaske and her company QMilk are turning that waste into 100-percent natural fibers that only require 2 liters of water per kilogram, Domaske says. For comparison, producing one cotton t-shirt uses up to 2,700 liters of water.

What if every building and car produced its own green energy? German company Heliatek has developed solar panels that are almost as light, thin and flexible as a sheet of paper. These "solar films" can be combined with other materials, for example glass or concrete, to create functional facades of houses or vehicles. The material can also be recycled.

In Japan, concrete wave breakers line beaches to protect the shore from erosion. The Okinawa Institute of Science and Technology wants to replace them with turbines that generate renewable power, at the same time as protecting the coast. If these small, five-blade "sea horse" turbines covered just 1% of Japan’s coast, they could generate as much power as 10 nuclear plants.

Hundreds of millions of plastic bottles are thrown away every day. Besides creating an enormous amount of waste, their production relies on chemicals derived from fossil fuels. Dutch chemist Gert-Jan Gruter has developed an environmentally friendly alternative: a sugar-based bioplastic that requires no petrochemicals, is completely recyclable and cuts associated CO2 emissions by up to 70 percent.

Speaking of plastic, a British company is turning plastic waste into an asphalt mix for roads. Plastic makes the roads stronger and longer-lasting. Governments save on maintenance, and millions of tons of waste plastic is given a second life. The plastic asphalt mix already covers several roads in the UK in Bahrain.

French firm Zephyr & Borée has combined traditional sailing with wind energy technology for 21st century eco-friendly transport. "Nowadays we can consume products that are organic, recyclable … yet there [are] barely any companies that offer a green supply chain," say the pioneers, adding that their sailing vessels produce 70 percent less CO2 than fuel-powered ones.

Two out three people in sub-Saharan Africa don't have access to electricity, particularly in rural areas. A German start-up has developed modular shops powered by the sun. This example in Kenya provides internet access, water purification and fridges for medication. Locals can also scan and print documents and recharge their cellphones.