Most houses use energy lots of it. We use energy for heating, lighting, for running our household appliances: TV's, washing machines, fridges, and so on. In winter time, most houses use dozens of kilowatts of electricity every day, or the equivalent in gas.
The house in the photo, on the other hand, uses virtually nothing: most of the energy that it uses comes straight from the sun, the wind or the ground. This is an experimental house at the University of Nottingham, and it could be the kind of house that most people are living in fifty years from now.
During the daytime, it is rarely necessary to turn on an electric light, even in rooms without windows. Sunlight, or daylight, is "piped" through the house, into each room, through special high-reflection aluminium tubes. You can see how well they reflect light, by looking at the reflections of the faces in the picture!
At night, of course, energy is necessary but most of this comes from the sun or the wind. The house is fitted with photovoltaic solar panels that generate electricity during the daytime, and a wind turbine power generator too; electricity from these can be used directly, or else stored in batteries, and used when it is needed.
For heating, the house uses direct solar energy (sunshine heating water that circulates through a radiator system), or geothermal energy. This takes low-level heat out of the ground, and uses a heat-pump to convert it into high-level heat for use in radiators the same principle as a refrigerator, but in reverse.
As for water, most daily needs are provided for by the house's own supply; rainwater is collected on the roof, filtered, and used for all toilets, baths and showers.
TEXT 2.Computers
Generally, any device that can perform numerical calculations, even an adding machine, may be called a computer but nowadays this term is used especially for digital computers. Computers that once weighed 30 tons now may weigh as little as 1.8 kilograms. Microchips and microprocessors have reduced the cost of the electronic components required in a computer. Computers come in many sizes and shapes such as special-purpose, laptop, desktop, minicomputers, supercomputers.
Special-purpose computers can perform specific tasks and their operations are limited to the programmes built into their microchips. There computers are the basis for electronic calculators and can be found in thousands of electronic products, including digital watches and automobiles. These computers do the ordinary arithmetic operations such as addition, subtraction, multiplication and division.
General-purpose computers are much more powerful because they can accept new sets of instructions. The smallest fully functional computers are called laptop computers. Most of the general-purpose computers known as personal or desktop computers can perform almost 5 million operations per second.
Today's personal computers are know to be used for different purposes: for testing new theories or models that cannot be examined with experiments, as valuable educational tools due to various encyclopedias, dictionaries, educational programmes, in book-keeping, accounting and management. Proper application of computing equipment in different industries is likely to result in proper management, effective distribution of materials and resources, more efficient production and trade.