It is thirty years ago that scientists from the University of Cambridge, England, discovered the hole in the ozone layer, the earth’s shield against lethal solar radiation. The discovery changed our lives in many ways, from international relations to the production of cosmetics. Ozone is a form of oxygen which absorbs ultraviolet radiation, which can cause skin cancer, among other things. Two years after the discovery, the Montreal Protocol was signed by 46 states, the first United Nations treaty to be universally ratified. 25 years later, consumption of 98% of the chemicals controlled under the treaty had been phased out by the signatory countries. The discovery of the ozone hole brought environmental issues to the center stage of international politics.
Researchers at the Aalto University in Finland and the Universitat Politècnica de Catalunya in Spain have achieved a 22.1% efficiency rate on so-called ‘black’ silicon solar cells. The average efficiency rate for solar cells is between 15% and 17%. The energy conversion efficiency is only one factor; black silicon cells are also capable of capturing solar energy from lower angles than traditional cells, so that they generate more energy over the course of a day. This is also an advantage in Northern regions, where sunlight comes in at low angles during most of the year.
Also from Spain comes a new type of wind turbine, the Vortex Bladeless, which is nearly noiseless and much smaller than traditional wind turbines, making it well suited for residential applications. The energy it produces can be stored in the same cells as solar energy, The technology makes use of the changes in air flow patterns when wind hits an obstruction – the same phenomenon that caused the famous collapse of the Takoma Narrows bridge in Seattle in 1940, but now put to good use. The current version is 10 feet high and produces 100 watts. The next version will be 40 feet high and produce four kilowatts.
PLASTIC VS GLASS
Only 1 in 5 water bottles is recycled. The decomposition time of the other 4 is 450-500 years. Not too bad, compared to a glass bottle, which takes a million years. However, a glass bottle decomposes into the sand it was made of, while a plastic bottle decomposes into the plastic it was made of.