Weekly newsletter - Monday 27th of December 2010
Best Green Supermarkets
The latest Ethical Consumers Buyers’ guide (released on the
17th of December) has named The Co-op and Marks & Spencer as
the UK's greenest supermarkets. 19 of the UK’s supermarkets
were surveyed and their corporate and social responsibility
policies were put under the spotlight. The co-author of the guide
admitted that although it was best to buy from a sustainably
stocked local store the reality was that many of us regularly shop
at supermarkets and that we should make our choice in favour of the
most sustainable and ethical stores. The guide looked at how
supermarkets source food, how they transport goods and how they
power stores. For example the Co-op aims to use 98% renewable
electricity in its 5,500 sites across the UK. The worst performing
companies were Tesco, ASDA and Netto.
Full press release and link to buy the guide.
New Solar Fuel Cell
A prototype solar fuel cell called a “solar cavity-receiver
reactor” has been created which uses solar rays to break down
water and carbon dioxide into fuels of hydrogen and carbon
monoxide. It is also possible to create methane using the device.
It works by concentrating sunlight into a cavity lined which cerium
oxide which strips compounds of oxygen as it cools. Cerium is the
most abundant of the rare earth metals. At the prototype stage the
device is only 0.7-0.8% efficient but this is limited by scale and
design rather than the underlying chemistry. Researchers expect to
be able to achieve 19% efficiency in the long run. When scaled up
the devices could be used to create fuel that is then transported
or to store fuel and burn it overnight providing 24 hour power.
Full story
here.
Although not an instant fix, this development is promising and
shows that work in the field of solar power is progressing. Most
photovoltaic panels have an efficiency of 20% (to which the solar
cavity-receiver reactor compares agreeably) and even the most
advanced designs using silicon are only able to achieve around
40%.