Monthly Archives: September 2011


On July 7th the German company SkySails GmbH was awarded the Sustainable Shipping Environmental Technology of the Year Award (for the second time) for its SkySail technology.

The SkySails system uses a computer controlled kite with an area of more than 160 square metres to harness the power of wind as an auxilliary power system for large marine vessels. The SkySails company claims it can reduce fuel consumption over long journeys by between ten and fifteen percent.

The SkySails system is a form of high altitude wind power (HAWP). HAWP systems are viable because the power available to wind power systems increases with the cube of the wind’s speed (e.g. if you double the speed the energy produced increases by a factor of eight) and wind speed increases rapidly with height. Companies like KiteGen are even working on using HAWP systems for electricity generation.

Lactose tolerance

Because most in the western world are able to digest dairy products it is often assumed that this condition (lactose persistence) is the norm. But if you are able to tolerate lactose then you are actually in a minority: ninety-eight percent of Southeast Asians and ninety-five percent of Chinese are lactose intolerant. Between them these two ethnic groups make up more than 28% of the world’s population.

The graph below shows some of the ethnic groups with over 50% of the population lactose intolerant:


Liquid cooling

Computer hardware produces a huge amount of heat when operating. Usually this heat is removed by a combination of heatsinks and fans

The grey heatsink conducts the heat away from the processor and the sink’s fins give the heatsink a larger surface area for the air moved by the fan to blow over. Some computers use very large heatsinks in order to do away with the need for a fan entirely, relying only on natural convection currents for cooling.

Some computers do away with fans by pumping water past the heatsink; water is a much better absorber of heat than air* and therefore the system uses less power for cooling.

Green Revolution Cooling have gone one step further – they actually submerge the computing hardware in a special non-conductive liquid. This liquid then circulates, transferring the heat away to an external evaporation tower.

They claim that their cooling system will pay for itself within 1-3 years.

* The specific heat capacity of air is 1.007 joules per gram per kelvin and the specific heat capacity of water is 4.187 J/g/K. This means that water will absorb more than four times the energy of the same amount of air for the same increase in temperature. Green Revolution don’t say what the specific heat capacity of the fluid they use is, but it’s likely to be greater than water’s.