Nowadays, as we have already mentioned,
provide most of our energy: it is a “convenient” form of energy because it is
concentrated, easy to transport and easy to store. There is, however, another
side to the "coin". Fossil fuels pollute, give rise to the
are becoming more and more expensive and will run out in few decades or centuries.
It would be a good idea in the near future to introduce
programmes in industrialized countries, getting citizens directly involved;
each one of us should be sensitive to a more moderate use of electric energy for
Many small solar power stations and also larger ones of various types are foreseen in the future: we cannot evaluate whether they are useful, economically viable or efficiently maintained until much later.
in the very sunny, semi-desert area of North Australia, a very special, enormous
solar power station is under study. Its circular shape is 6 km in diameter, with
a surface area of 28 km2 (Fig. 1). The air under a transparent cover is heated
by the sun and conveyed towards a 1 km-high chimney in the centre of the disc,
thanks to the effect of an upward going current generated by the difference in temperature
between the base (hot) and the top of the chimney (cold). Several turbines
are situated inside the chimney which will generate electricity with an overall
power of 200
(a small prototype is working in Spain).
The electric energy generated will be transported by a high-tension network to
relatively large distances. One of the characteristics of this system, which
distinguishes it from all others, is that it will produce electricity day and
night. In fact, at night underground water reservoirs preserve the heat and thus
maintain the upward movement of the current, albeit with reduced efficiency
compared to the hotter daytime.
As far as photovoltaic panel technology is concerned, efforts should be made as soon as possible to improve both performance and electric components, and especially to reduce costs. Incentives should also be introduced, based on the effective production of electricity, and more efficient maintenance systems should be designed.