Mirroring European Change
By Ronald Rovers – Novem
The design and visual appearance of roofs across Europe has always been the source of much variety - with every roof portraying subtle details of its inhabitant's specific life-style and their immediate environment.
In Northern Europe and the Alps roofs are characterised by their slight incline - steep enough to guide rain downwards but not so steep as to discourage settling snow, which serves to insulate the building during severe cold.
Throughout the middle of Europe roofs get a great deal steeper, this is most true of densely populated city areas. In these scenarios steepness is due to space limitations and fiscal restrictions - a steep roof can provide vital extra living space in such an over-crowded environment. In contrast, the norm in undeveloped areas of Southern Europe is that of a flat roof. Such roofs are characteristic of warm climate buildings and the elevated flat space is well employed as a roof terrace.
At the moment a fascinating period of solar development lies before us, and the solar panel will be challenged to adapt and complement all these differing established roof-forms. It is yet to be fully observed how Europe's varied cultures will react to the introduction of new and exciting renewable roofing. However, it is certain that Europe is already mirroring the shape of the things to come and looking forward to a sustainable future.
New roof on an old school in Gothenburg with new built lanterns for natural ventilation and daylight (Thermie-96 projects. MEDUCA group)
THE SUSTAINABLE ENERGY INDUSTRY JOURNAL, September 2003
Questions for text:
Tell about peculiarities of roofs in Northern Europe.
What can you say about roofs in South Europe?
How does the period of solar development influence upon roofing?
Geothermal Energy
Outlook for Geothermal Energy
Geothermal resources occur throughout the world, and are particularly abundant in many developing countries where their utilization can displace the development of polluting fossil fuel-fired power plants. This is an important consideration because once the investment is made in a fossil plant, the global atmospheric commons will be expected to absorb the resulting pollution stream for decades. Geothermal power plants are available in size ranging from about 300 kilowatts net electrical output to 55 megawatts. They can be installed in modules as electrical demand grows. Although not generally recognized, geothermal power generation can and will play a significant part in rural electrification of developing countries. Geothermal plants are generally operated at constant output to furnish base-load power, but their output can also be varied between reasonably wide limits depending on the thermal cycling limitation of production wells and steam delivery equipment.
Presently, about 7000 megawatts of geothermal electrical power generation are on line in some 20 countries, including (but not limited to) China, Costa Rica, El Salvador, Iceland, Indonesia, Italy, Japan, Kenya, Mexico, New Zealand, Nicaragua, Philippines, Romania, Russia, Thailand, Turkey, and United States. The largest operating geothermal field is The Geysers in USA, which currently produces about 1300 megawatts. By some estimates, as such as 80000 megawatts of geothermally generated electrical power are available from volcanic systems in developing countries throughout the world. Indonesia alone estimates its potential 19000 megawatts.
Direct applications of geothermal resources are also important, and comprise more than 12000 thermal megawatts of use. The vast of majority of the homes and buildings in Iceland are geothermally heated, and district heating systems also are operated in the Paris basin, in several US cities, in New Zealand, and elsewhere. Greenhouses heated with geothermal waters exist in many countries worldwide. Food drying is another established use. The vast potential for direct applications of geothermal resources has barely been touched.