The first solar house had southern siting with a collector surface of 40 squares meters on its roof. The water which was warmed up by the collector was pumped to a cistern located at the basement by a pump. It was a 70 square meters large cistern warming up the air in the basement. The hot air was blown into the accommodation by ventilators. The experiences showed, that the centigrade did not decreased to 22 Celsius even in winters. At the same time because of the collector’s big surface and the huge cistern it was so expensive, that it was impermissible in dwelling-houses settings.

The second solar house was built in 1947 in a quite different way from the first one. Heating temperature was supplied by double-glass-covered heating walls vertically located at the southern side. They were vapid metal boxes painted black and bordered by absorbs. From the heating wall the hot air was directed towards the inner part of the house by a natural connective flow. Against getting overheated the heating walls were covered by white blind curtain. In case of decreasing he temperature under 22 Celsius, the curtains were just pulled up.  As a result this solar house has not been found to be successful by the researchers. The heating walls were covering 38-48% of the hole heating energy, but the deficit was too much, and running the curtains have made it’s operation difficult, so this solution has finally been rejected.

The third solar house was built by qualified principle in 1949. Economic factors were more considered during the planning than they previously had been. In one hand, it wasn’t a goal to cover all amount of the heating energy  of the house from solar energy, so smaller collectors had been built in. On the other hand, further heating profit could be reached by large surfaced and southern siting windows. Water heated up by the collectors was also collected into a basic cistern, wherefrom the warm air –similarly first solar house- has been passed onto the accommodation by ventilators. However the cistern was much smaller than in the first solar house was.

Compearing to the previous tests it was new that this solar house was used as a dwelling house, and one of the university’s young tutors moved here with his family. Operating of this solar house was successful: 44% of the heating temperature was supplied by the collectors, 29% by the southern siting windows, while furniture and equipment accounted for further 16% and the just rest of 11% had to be supplied by the electric heating centre.
From all the test houses this one was the most successful, working successfully till 1953, when it burning down in a fire caused by an electric arrest.

The fourth solar house was built in 1958 according to the similar principals as the previous on in essence. Economic factors were more considered in planning and the house was deplored as a prototype of a standardized production’s model.  Unfortunately this design had not been fulfilled it’s hopes: as the collectors gave only 50% of the heading temperature. Anyway the house was working until the M.I.T’s end in 1962.

The most important result of this program was to prove that heading with solar energy of dwelling houses is even possible in cold temperatured territories such as Massachuset.

Transforming solar energy into electrical energy:
Edmund Becquerel the Nobel-prize winner Henry Becquerels father discovered the Becquerel effect in 1839. The juice of this: a metal electrode interlocking with an electrolyte changes its potential if it gets light. This is the root of PV panels. An American inventor, Charles Fritts made the first selenium PV panel in the end of the year 1880. However this panels efficiency was lower than 1%. After discovering the photoelectric effect (in the beginning of the year 1930) a number of persons started again to deal with the execution of PV panels, but the bad efficiency of the discovered selenium PV panels didn’t motivate the further researches. In 1954 in the Bell Laboratory three investigators:Gordon Pearson, Darryl Chapin, and Calvin Fuller started to experiment with silicon. In the first experiments they achieved an efficiency of 4%,than after other perfections they generated the 15% efficiency PV panel. Their results were very famous, numbers thought PV panels to be the futures “green” (it doesn’t pollute the nature) energy sources. Not, much later it turned out that its costliness so it can’t be used everywhere. However in some special cases it is integral. Such is the distant territories energy-supply, and principally the space researches. The USA during its space researches generated a significant PV panel industry. PV panels are used in many other little energy using up electrical appliances. For example in calculators, radios, and in some electric torches. The solar energy should be used in more places, and should be preferred against fossilized energy sources, because it doesn’t pollute the nature and the fossilized energy sources price will decrease.

The buildup and attribution of PV panels:
It is an application made out of semiconductor, which transforms the energy coming from our Sun to electric current. It is made of two streaks in the one of them electrons and protons spring up while light is absorbed, the other streak is a potential barrier, which separates the electrons and protons. Usually it is made of silicon, but it could be made of semiconductor compound too (but this is more expensive that’s why it is used rarely). In favour of the better utilization the surface of the PV panels is muffled with an antireflection scale. Sun cells are primary important energy sources of space stations and satellites.

Solar power stations:
Between 1984 and 1990 the Luz International built eight solar power stations in California. The power stations operated with parabolic cross section, line focused collectors, and its all output was 355MW. The same time executions were made to engage power stations which have a furnace on a tower, and in the furnace the water is warmed up with mirrors focused on the furnace. The first power station like this was the Solar One. It stood on a 76m high tower. To its furnace 1860 pieces of mirror was focused, which were one by one 40 square meters. Every mirror could be moved in every direction. So the furnace could be warmed up all day. The output of this power station was 35MW. From the years 1880 several power supply stations were built.
One of these and the biggest was founded in Carissa Plains (USA) in 1984-85. The output of this power supply station was 5,2MW.
 

In 1990 the apparatus was dismounted because of the solar cells aging and setback and the cells were utilized in smaller energy supplier systems. Many solar systems were built, which efficacies were much smaller in the USA, in Germany, Switzerland, in Netherlands and so on. An interesting tentative power station was built in Florida in 1988. Its achievement was 15kW. Its modules were from amorphous silicon-diodes. These were much cheaper than the conventional crystalline silicon, but even their efficiency was less. The efficiency of this system felt off by 25% in three years, so in 1991 the efficiency was only 4%.

Solar energy or conventional energy?
Unfortunately producing energy by solar cells is still more expensive than by the traditional way. However nowadays the utilization of the solar energy is being urged, it is more favorable in many ways than the utilization of the conventional energy. Solar energy is a renewable energy so we won t run out of it while the sun shines. Besides the solar energy doesn’t pollute the environment, moreover it could be used even in those territories where anyway it is cold and winter. The disadvantage of the solar systems is that it is no use to build solar tentative system whereto it doesn’t return, because it costs much. However more tentative power stations should be built, we think it will return. By the time the quantum of the fossilized energy sources decrease, they will getting more expensive so the solar cells and solar tentative systems would be very usable. If every country had its own energy supplier, they wouldn’t depend on other countries.

Vehicles using solar energy:

Car with solar cells:it crossed Australia in 20 days in 1984. Its name is Quiet Achiever. This car also purports accumulators, which store the energy for night, cloudy weather or upgrades.

Plane with solar cells: an airplane called Solar Challenge reached the achievement of 2.5 kW by 161128 solar cells. This plane hopped the La Manche in 1981.