Monday, May 25, 2009

Wind Power

The Earth is unevenly heated by the sun resulting in the poles receiving less energy from the sun than the equator does. Also, the dry land heats up (and cools down) more quickly than the seas do. The differential heating drives a global atmospheric convection system reaching from the Earth's surface to the stratosphere which acts as a virtual ceiling. Most of the energy stored in these wind movements can be found at high altitudes where continuous wind speeds of over 160 km/h (100 mph) occur. Eventually, the wind energy is converted through friction into diffuse heat throughout the Earth's surface and the atmosphere.Humans have been using wind power for at least 5,500 years to propel sailboats and sailing ships, and architects have used wind-driven natural ventilation in buildings since similarly ancient times. The use of wind to provide mechanical power came somewhat later in antiquity.

The Babylonian emperor Hammurabi planned to use wind power for his ambitious irrigation project in the 17th century BC[4]. The ancient Sinhalese utilized the monsoon winds to power furnaces as early as 300 BC evidence has been found in cities such as Anuradhapura and in other cities around Sri Lanka[5] The furnaces were constructed on the path of the monsoon winds to exploit the wind power, to bring the temperatures inside up to 1100-1200 Celsius. An early historical reference to a rudimentary windmill was used to power an organ in the 1st century AD.[6] The first practical windmills were later built in Sistan, Afghanistan, from the 7th century. These were vertical-axle windmills, which had long vertical driveshafts with rectangle shaped blades.[7] Made of six to twelve sails covered in reed matting or cloth material, these windmills were used to grind corn and draw up water, and were used in the gristmilling and sugarcane industries.[8] Horizontal-axle windmills were later used extensively in Northwestern Europe to grind flour beginning in the 1180s, and many Dutch windmills still exist.

Wednesday, May 20, 2009

Economics-Supply and Demand

Today we are studying economics and haw the market works. The Practical uses of supply and demand analysis often center on the different variables that change equilibrium price and quantity, represented as shifts in the respective curves. Comparative statics of such a shift traces the effects from the initial equilibrium to the new equilibrium.
When consumers increase the quantity demanded at a given price, it is referred to as an increase in demand.

Wednesday, May 6, 2009

Eco Houses

Hi everybody it's bobby here did you know that an internationally renowned energy expert believes New Zealand could generate all its electricity from renewable sources within twenty years. Wow!!!!!!!!

Eco House are built in such a way that reduces energy consumption and waste. Eco Houses reduce the buildings bad impact on human health and the environment, through better design, construction, siting, operation and maintenance. Eco Houses are a combination of sustainable design, sustainable development and sustainable living. Eco houses are designed and built as part of the larger ecology of the planet; the design and construction of the building are done in harmony with the natural environment. Studies have shown that buildings are the most damaging polluters on the planet, consuming over half of all the energy used in developed countries and producing over half of all the climate-changing greenhouse gases. A successful eco house should give the owner the ‘best of both’ by providing less of an impact on the environment along with a healthier place to live and lower ongoing running costs. Eco Bob

Personly I go for Eco. On the Matai island I will stay eco and try to keep it going through my family.