Energy is the capacity to move, to change, or to work.
Power is "strength", the speed of work, the speed of energy use. A horse has the power of about 20 men.
A human needs about 2600kCal=3kWh food energy per day, of which 1kWh/day can be used to perform work.
All our energy is basically derived from incoming sunlight.
Fossil energy is sunlight that nature has accumulated and stored over a time span of hundreds of millions of years.
Our current life-styles are almost totally depend on stored energy, depleting it at a speed that is one million tiimes faster than the daily amount of incoming sun energy. This cannot last.
Modern life depends on machinery, which depend on fossil energy.
Even so-called "renewables", like solar, wind and hydraulic electricity, depend on fossil fuels for the construction and maintenance of solar panels, wind turbines and electricity dams.
Modern agriculture requires fertilers, irrigation, and farm machinery, which largely depend on fossil fuels. The conversion of crops into food products in the supermarket requires transportation and factories, all dependent on fossil fuels.
Energy units are kcal, BTU, GJ, kWh, QUAD, barrils of crude oil, tons of coal.
Power units are Horsepower HP, kilowatt kW, Britisch thermal Units per hour BTU/h, and Man-Power MP. One MP is approx. one twentieth of a HP. A horse can perform work at the speed 20 men. [energy conversion tables]
under development (5 November 2010) > click to comment
Letter on Sustainability and Bio-fuels to the former Dutch Prime Minister Ruud Lubbers
- The perpetuum velobile,
- The green growth machine
striving for the highest possible scientific validity.