The concentration of greenhouse gases in the atmosphere has been dramatically rising for the past 150 years. This fact and the possible link between GHG concentration and rising temperature of the Earth caused that the reduction of greenhouse gases has recently emerged as widely discussed issue.
First step to cut CO2 emissions is to identify countries with the highest contribution to the worldwide emissions. From this point of view the emissions of China and USA are very similar.
However the information about absolute CO2 emissions per country is not fully correct for most of comparisons. Much better is to compare CO2 emissions per capita. From this point of view, which comes from idea that every people have the same right to consume the natural resources and produce waste, the emissions of China are much lower than that of the USA.
Information about CO2 emissions is relatively simple indicator. There are more complex indicators that should be used in case of sustainable development assessment.
In the 1970's the interest in renewable energy sources increased considerably due to the energy crisis. At that time, the fist extensive and reputable studies were published, which talked seriously about the fact that conventional energy sources are exhaustible. The Czech republic adopted its first energy policy in 1992 in agreement with the regional environmental limits of coal.
The article deals with real experiences of growing of an energetic crop - the sorrel. There are described four selected locations concerning the crop production and applied treatment, including future outlook. The article also includes the price estimation of energy of 1 GJ from the sorrel, based on available data.
The second article on heat saving when adjusting heating systems is focused on the importance of good transfer of heat between external and internal networks. including the effect on the activation of temperature sensors and economical operation of dynamic heating systems, including the effect on the activation of temperature sensors and high-economy operation of the dynamic heating systems (thermostatic valve reverse curve, the dependence of operating parameters on the system differential pressure and problem solving of the central heating supply thermal hydraulics)
The article contains supporting evidence for the treatment of heating systems, describes the effect of adjustments to the internal wiring and piping on the outside heat supply network of central heating (CPP), analyzes the causes of low heat savings and provides information on the best solution practices for actual adjustments.
Air conditioning and ventilation systems show big energy consumption in buildings. Measure of the consumption of electrical energy for the conveyance of air is SFP. SFP is defined as the total consumption of electrical energy by the all of fans in the air-distribution systems, defined by the total volumetric air flow through the operated space under nominal loads. The article presents influence of design equipment on energy consumption.
Products resulting from the combustion of gas that contain harmful substances (carbon monoxide CO, carbon dioxide, CO2, water vapor, H2O) can penetrate into a room during the activity of Type A gas appliances. The concentration of oxygen, O2, also decreases during the combustion of gas. Water steam should also be considered harmful. The results of calculations show that the rate of humidity is most important for determining the minimum volume of the room or the minimum volumetric flow rate of ventilation air.
Lately, the Czech Association of Technical Equipment has been approached by several manufactures who wanted to know whether it is possible, in accordance with Czech legal practices, to have their products certified by a variety of accredited certification bodies, and very often applied to products that have already been certified by an authorised person. These additional certifications are very often a condition for the use fo some products in the field of gas equipment.
The article reacts on changes that were made in program "Zelená úsporám" in recent days. Previous article described how to reach required standards for successful subsidy application in two ways. Following text focuses on changes in this approach both from subsidy amount and possibility of subsidy itself viewpoints. In general, portfolio of potential subsidy applicants has been extended, but necessary quality of subsidized measures has been kept.
Contrary to the long term norm, the heating period has been considered 6% less intensive. After having examined a number of recent years, it can be said that the consumption of heating during this winter was within the normal. The distribution of the heating demand, however, shows an imbalance in individual months, with the consumption until January being below the average. In comparison with a thirty year average and the previous eight heating seasons we have a continuation of a subnormal, i.e. warmer, period.
The author deals with a numerical analysis of temperatures and flow fields in heated rooms in relation to the location of the radiator. Two designs for radiators are discussed in the form of four possible solutions. A radiator with a classical design was placed under a window on the wall cladding, on an inner wall and on an inner wall opposite. A radiator designed with a balance method was placed only under a window.
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.
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.
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.
The article includes the epitome of project documentation that is not available in the technical practice or that is newly elaborated but that is necessary for the reconstructions, replacements of obsolete radiators and for adaptations of heating units performance connected with the heat cladding of the construction objects.
