The energy radiating to the Earth from the sun is free, and will never run out during human lives. Its use is essential if we are to reduce the combustion of fossil fuels. However, it will not be enough simply to increase the supply of energy: it is also vital that we should learn to use energy more efficiently. Concepts such as energy economics, energy accounting and energy management will become increasingly important in the future. Various initiatives intended to improve the efficiency of energy use are being expressed in the form of new EU directives. The phasing out of incandescent lamps, for example, is expected to reduce the quantity of electricity used in Europe by an amount equal to the entire electricity use of Hungary.
Energy supply is also bound up with independence and security. Present-day energy systems, with their dependence on oil and raw materials, are extremely vulnerable to economic and political disturbances. Prices represent a considerable risk element, and energy can quickly become bound up in market wars and political struggles.
olar energy, as a form of energy source, has an inherent stability and reliability. Its production technology is fully costable, so that its price over the next 20 30 years can be calculated. In addition, a solar energy plant means that an energy purchaser is in a better negotiating position than he would be if he were able only to choose a specific energy source from a specific supplier.
Solar energy will not be our only source of energy, even though the insolation on the roof of a typical Swedish detached house supplies five times more energy per year than the house uses in total. Additional energy will be needed on cold winter days, which means that thermal solar energy in particular will have to be complemented by other forms of energy, such as biofuel based district heating. We therefore need an acceptance of the limitations and conditions of the technology, together with an understanding of how other forms of energy systems work and how they can all work together in a single system.
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COP of 50 200 for solar energy
The Coefficient of Performance (COP) is a concept used to indicate the efficiency of (for example) heat pumps or other means of delivering energy. It is given by the result of dividing the quantity of useful energy delivered by the amount of energy put into the process. COP is an important indicator of the efficiency of heat pumps. Heat pumps have a COP of about 3–4, which means that one unit of energy input (electricity) delivers 3–4 units of useful energy (heat). If we apply the COP concept to a solar energy plant, delivering electricity or heat, we obtain COPs in the range 50–200.
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