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Archiv článků od 14.9.2009 do 19.10.2009

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19.10.2009
Bronislav Bechník

Energy Regulatory Office (ERÚ) announced „adequate“ feed-in-tarif (FiT) for photovoltaic electricity. Based on actual situation on Czech PV market it is recommended to reduce FiT for systems below 30 kWp to 11 200 CZK/Wp and for systems above 30 kWp to 9 000 CZK/Wp (actual exchange rate is 25,785 CZK/EUR, see this site).
The recommended values of FiT correspond with actual situation on Czech PV market. Unfortunately exchange rate of Czech koruna (CZK) to Euro is instable. Exchange rate of Czech koruna to Euro oscillate in wide range from about 28 in beginning of 2008 to about 23 in August 2008 and back to about 29 in February 2009. In case the exchange rate will be on upper level the growth of photovoltaic installations will cease. On lower level FiT will be very profitable again.
On other hand future prices of PV modules are unpredictable. Actual rapid fall of prices is mostly based on decrease of price of Silicon as raw material. If the price of Silicon will rise after financial crisis will end, the prices of PV modules will rise too. The prices of modules will probably never exceed last year level, however prices high above 2 €/Wp are possible. According to those uncertainties the FiT could become either excessively profitable or purely restrictive.

12.10.2009
Tomáš Matuška, ČVUT v Praze, Univerzitní centrum energeticky efektivních budov, Ústav techniky prostředí, Fakulta strojní, ČVUT v Praze

The application potential for solar energy use in buildings lies in supply of thermal and electric energy and natural daylighting. To use incident solar energy from building envelope effectively, multi-functional construction elements combining several purposes should be introduced as a standard part of building construction. Examples of such concepts are presented: hybrid air/liquid collectors for heating and ventilation purposes, hybrid photovoltaic-thermal (PV/T) collectors for combined thermal and electric energy supply (glazed, unglazed, air/water cooled), linear Fresnell lenses collectors for removal of heat load from direct component of solar irradiation to thermal storage and allowing the natural diffuse daylighting.

5.10.2009
Ing. Ondřej Šikula, Ing. Olga Rubinová, Ph.D., VUT v Brně, Fakulta stavební, Ústav technických zařízení budov

Solar collector is designed to obtain part of heating requirements of the buildings from the sun. Air-type collector that use air as the heat transfer medium is one of the simplest methods of solar heating. This solar heating technique can be made part of house design and construction.

28.9.2009

Even wind power plants need means of transportation to take service crews to their workplaces. At the moment, there is no European standard for this kind of equipment – though it is prepared, so let's have a look through the eyes of the author of this article at how this issue is seen in North America, and what was exhibited related to it at the trade fair in Chicago.

28.9.2009
Bronislav Bechník

From point of view of energy balance every biomass is accumulated solar radiation. It is estimated that about 30 % of biomass is used as food and feed and 20 % is production of forest. Despite fossil fuels the biomass is the most significant energy source in the world. Recently it is not issue however in case of large expansion the energy use of biomass can compete with use as food and feed.
In the Czech Republic it is assumed that the biomass will remain the most significant renewable energy source (RES) at least until the end of the next decade. Energy potential of biomass is limited by production ability of landscape on one hand and by other opportunities of use of biomass on other hand. Expansion of the other opportunities is usually not taken into account in energy predictions.
Energy balance (EROEI) of biomass plantation strongly depends on proportion of use of heavy machinery and transportation distance. EROEI of spatial energy crops is better than that of food production. Although energy yield is highest when the biomass is harvested in summer the biomass harvested next year in spring contains much less moisture and thus is suitable for direct combustion.
Compared to other RES the advantage of the biomass is easy accumulation or (if you like) possibility to harvest in desirable time, easy control of energy supply in accordance with actual demand. In most cases exploitation of equipment designed for fossil fuels is applicable. In renewable energy mix responsible position of biomass is (despite other potential) in balancing of production of sources that are fully dependent on weather - photovoltaic and wind.

21.9.2009
Ing. Tomáš Matuška, Ph.D., ČVUT v Praze, Univerzitní centrum energeticky efektivních budov, Ústav techniky prostředí, Fakulta strojní, ČVUT v Praze

Guaranteed solar results concept introduces a way how to assure the energy savings of realizied solar systems, the economics of installations and declared reduction of emissions. Guarantee of savings creates a pressure on system supplier to deliver the best quality automatically and provides a surety bond for investor at the same time.

14.9.2009
Bronislav Bechník

From point of view of energy balance every biomass is accumulated solar radiation. It is estimated that about 30 % of biomass is used as food and feed and 20 % is production of forest. Despite fossil fuels the biomass is the most significant energy source in the world. Recently it is not issue however in case of large expansion the energy use of biomass can compete with use as food and feed.
In the Czech Republic it is assumed that the biomass will remain the most significant renewable energy source (RES) at least until the end of the next decade. Energy potential of biomass is limited by production ability of landscape on one hand and by other opportunities of use of biomass on other hand. Expansion of the other opportunities is usually not taken into account in energy predictions.
Energy balance (EROEI) of biomass plantation strongly depends on proportion of use of heavy machinery and transportation distance. EROEI of spatial energy crops is better than that of food production. Although energy yield is highest when the biomass is harvested in summer the biomass harvested next year in spring contains much less moisture and thus is suitable for direct combustion.
Compared to other RES the advantage of the biomass is easy accumulation or (if you like) possibility to harvest in desirable time, easy control of energy supply in accordance with actual demand. In most cases exploitation of equipment designed for fossil fuels is applicable. In renewable energy mix responsible position of biomass is (despite other potential) in balancing of production of sources that are fully dependent on weather – photovoltaic and wind.


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