Nejnavštěvovanější odborný web
pro stavebnictví a technická zařízení budov
estav.tvnový videoportál

Obnovitelná energie a úspory energie
Archiv článků od 6.5.2013 do 28.10.2013

Archiv recenzovaných článků

zpět na aktuální články

CO2
28.10.2013
Ing. Bronislav Bechník, Ph.D.

The article is a commentary on Czech TV report about the feasibility of reducing CO2 in the atmosphere. To eliminate carbon dioxide from the atmosphere has been proposed a number of methods, many of which are currently at the stage of mere concept. Namely, this includes the artificial trees mentioned in the report. Even if such methods work, there still remains the question of what to do with the captured CO2. Storage in geological formations is uncertain and material recovery faces high energy demands. In some cases there is a misunderstanding resulting from the confusion of CO2 and other emissions. Namely on the facade, which allegedly eliminate CO2 from the air, but in fact it eliminates nitrogen oxides. The only reliable way to reduce CO2 emissions permanently is to reduce energy consumption.

Fotovoltaické panely na střeše
14.10.2013
Ing. Bronislav Bechník, Ph.D.

Solar radiation can be utilised in two basic ways. You can either gain heat from solar thermal collectors or electricity in photovoltaic panels. So far, heating of water by photovoltaics was too expensive to compete with conventional solar thermal collectors.
Weight , durability , and currently even the price of solar thermal collectors is comparable with commercially available photovoltaic modules.
Annual energy yield per unit area is approximately twice in the solar thermal collectors compared to the highest quality photovoltaic modules with cells made ​​of monocrystalline silicon, due to the higher efficiency.
In the summer the photovoltaic modules are better when the working fluid is heated to temperatures above 100 °C. In the winter the breaking point is about 40 °C. The advantage of photovoltaics is the absence of heat transfer fluid and easier transfer of energy produced to the point of use. Electricity can also be used more versatile than heat.
If the investment cost of a complete solution of heating water by electricity from photovoltaic panels, either directly or using a heat pump, is lower than the investment cost of the solar thermal system, the PV water heating can be considered as effective utilization of electricity from photovoltaic plants. Such a solution could then be included as an alternative to any grant support for solar water heating.

komíny chrlící kouř
12.10.2013
Ing. Bronislav Bechník, Ph.D.

IPCC Working Group I is pleased to announce the launch of the new website as part of the Working Group I contribution to the IPCC Fifth Assessment Report.

9.9.2013
Ing. Vladimír Stupavský, redakce TZB-info, Klastr Česká peleta

The joint program to promote the replacement of boilers is spreading to various regions of the Czech Republic. The aim is to reduce subsidies to air pollution from small combustion plants using solid fuels. Refers to the local heating of the heat output of 50 kW. The subsidy is provided to the various types of boilers and applies only to the replacement of existing manually filled with solid fuel boilers with new efficient low-emission sources.

nová tramvaj ve městě
2.9.2013
Ing. Bronislav Bechník, Ph.D.

It is much more efficient to produce mechanical work by electrical engine "fuelled" by photovoltaic modules than produce the same amount of mechanical work by internal combustion engines running on fossil fuel or first-generation biofuel. The first choice could be much cheaper and produce order of magnitude more energy from agricultural land than biofuels. Therefore photovoltaics could hypothetically contribute significantly to the fulfillment of national and European target for the share of renewable energy sources (RES) in transportation.

obnovitelné zdroje
18.8.2013
Ing. Bronislav Bechník, Ph.D., redakce

The Chamber of Deputies approved the stopping of subsidies (feed-in-tariff) for renewable energy sources beginning January 1 2014. Support for combined heat and power generation from fossil fuels and support combustion of waste based on the same legislation remained unchanged.
By the opinion of the Chamber of RES the provisions of the law requiring a proof of beneficiaries structure is insufficient "especially because it does not apply to owners up to 10% of the shares and efficiency is only proposed from 1 July 2014, which gives a disproportionately large space to conceal the ownership structure."

12.8.2013
Ing. Marian Brázdil

The thermoelectric transformation of waste heat into electric power is considered to be a promising technology enabling to enhance electric efficiency of current energy processes, fuel saving and emissions reduction. The submitted paper deals with the construction of thermoelectric generators, current thermoelectric applications and their potential utilization.

29.7.2013
Hermann Laukamp, Robin Grab, Heribert Schmidt

Recently broad media in the Czech Republic coverage on hazards from PV systems to fire fighters. Similar situation was in Germany two years ago. That is why Fraunhofer-Institut für Solare Energiesysteme ISE together with TÜV Rheinland and other partners implemented a research project „Assessment of fire risks in PV systems and development of safety concepts for risk mitigation“. The project concluded that the fire risk of PV system is much less than it is publicly alleged in Germany.
There is a small risk that fires can be started by PV components. This risk can be reduced by careful installation, initial verification i.e. inspection and testing, periodic verifications, (yield) monitoring to detect degradation problems, and verification of test procedures and maintenance requirements for conventional AC- components. Overall conclusion is that PV systems are not maintenance free.

Whole presentation from EU PVSEC (in English).

Mikrořasy jako zdroj surovin
15.7.2013
Ing. Luboš Stříteský, prof. Ing. Petr Hlavínek, CSc.

The potential of microalgae as a source of renewable energy received lately large attention. Microalgal biomass is a potential source of renewable energy and it can be converted into energies such as biodiesel, ethanol, combustible gasses or it can be used to produce pharmaceutical, food additives and other. If microalgal biofuel production is to be sustainable and economically acceptable, further optimization of microalgae production and its conversion to viable compounds is needed. Microalgae are photosynthetic microorganisms with simple growing requirements (light, sugars, CO2, nitrogen, phosphorus, and potassium) that can fixate CO2, produce lipids, proteins and carbohydrates in very short periods of time.
These products can be processed into both biofuels and valuable co-products. Municipal, agricultural and industrial wastewaters are able to satisfy growing requirements of microalgae and hence provide cost-effective sustainable biofuel production with simultaneous wastewater treatment. Integration of biofuel production and wastewater treatment has major advantages for both industries, however major challenges needs to be overcome in order to implement such facilities in large-scale. This paper reviews current status of this topic with focus on fuel production with simultaneous algae wastewater treatment and major technological challenges.

Co s krachujícím trhem s emisními povolenkami?
8.7.2013
Klára Sutlovičová, Centrum pro dopravu a energetiku

The emissions trading scheme, EU's flagship climate policy tool, is at a turning point. With the price of carbon hovering way below €5 per tonne and a glut of permits on the market, something must be fixed or the instrument will turn to dust. As a first step towards correcting the problem, the European Commission has proposed a measure to withhold pollution permits temporarily, a process called ‘back-loading'. Back-loading appears harmless enough as all withheld allowances would re-enter the market before the end of this decade. Therefore the European Commission and many stakeholders recognise that structural measures are needed so that the ETS would support the transition towards a low-carbon economy.

27.6.2013
Ing. Bronislav Bechník, Ph.D., redakce

List of all companies that offer recycling of photovoltaic modules in the Czech Republic is included. Already 9 companies is on the list, of which 4 already received marketing authorization, 5 more likely to gain the authorization in the coming days. Contract can be concluded even with a company that has not received the marketing authorization yet.

Výroba elektrické energie z obnovitelných zdrojů v českých domácnostech
24.6.2013
Mgr. Hana Škopková, Univerzita Karlova v Praze, Centrum pro otázky životního prostředí a Fakulta humanitních studií

In order to assess the diffusion rate of solar and wind power plants in the Czech residential sector, we analyse data on licenses for business in the energy industries. We arbitrary set the maximum installed capacity for installations on residential roofs on 10 kWe and find out that the current number of such installations corresponds to 0.5 % of inhabited family houses in the Czech Republic, with most installations being in the Pilsen region and least in the Karlovy Vary and Liberec regions.
When compared with the overall development of solar power plants, it shows that the installations of up to 10 kWe accounted for about 35 % of all the solar power plant installations, but only for 1.9 % of the total installed capacity. Micro wind turbines are up to now not very expanded; we found only 20 installations of micro wind turbines.

11.6.2013
Ing. Bronislav Bechník, Ph.D.

Recycling of PV modules in the Czech Republic is not guaranteed despite of that four companies offer the recycling already. Besides two (specialised to recycling of PV modules) subsidiaries of traditional recycling companies, third traditional recycling company cooperate with PV Cycle, and fourth company was recently established by ten stakeholders including Czech Photovoltaic Industry Association and some large operators of PV power plants. Czech legislation does not guarantee that collected money will be available when recyclation will occur.

Změny v druhové skladbě českých lesů
3.6.2013
prof. Ing. Vilém Podrázský, CSc., prof. Ing. Jan Kouba, CSc., Ing. Daniel Zahradník, Ph.D., doc. Ing. Igor Štefančík, CSc.

Forestry and forest management plays many roles in the landscape and in the socio-economic area. Forests represent a landscape stabilizer, the best preserved part of the landscape of predominantly natural character with significant application of natural, spontaneous process. It also serves as a source of material benefits to human society. The wood-producing function of forests was questuioned in this country in recent years. Above all, leaders of various environmentalist movement are demanding ever greater proportion of forests without economic activity. However, forestry is afflicted by such influences by decades and the aim of this paper is to demonstrate possible implications of these trends for forestry and subsequent economic sectors.

Obnovitelné zdroje v českých domácnostech k vytápění a přípravě teplé vody
3.6.2013
Mgr. Hana Škopková, Univerzita Karlova v Praze, Centrum pro otázky životního prostředí a Fakulta humanitních studií

The paper analyses available data sources on the use of renewable energy in Czech households from which it is possible to derive the current distribution of these sources in the Czech residential sector. Available data provide information about biomass, solar and heat pump installations. The data indicate that the most frequently used renewable energy source among Czech households is biomass, which is the main source of heating in approximately 8 % of inhabited dwellings. Heat pumps are installed in 0.5 % and solar energy is used in at least 1 % of all the Czech inhabited dwellings. It also indicates that these renewable energy sources are far more used in detached family houses rather than in apartment houses. Overall, most of the renewable energy sources used in Czech households are in the Central Bohemian Region, the least in Karlovy Vary Region and the capital city of Prague. Although the datasets do not provide enough evidence to derive any reliable development trends, they provide useful information on the minimal distribution of these resources in the past 10 years and also the effect of selected policy instruments to support the use of these resources on Czech households in comparison with the situation before they came into force.

Obnovitelné zdroje energie v českých domácnostech
27.5.2013
Mgr. Hana Škopková, Univerzita Karlova v Praze, Centrum pro otázky životního prostředí a Fakulta humanitních studií

The paper analyses available data sources on the use of renewable energy in Czech households from which it is possible to derive the current distribution of these sources in the Czech residential sector. Available data provide information about biomass, solar and heat pump installations. The data indicate that the most frequently used renewable energy source among Czech households is biomass, which is the main source of heating in approximately 8 % of inhabited dwellings. Heat pumps are installed in 0.5 % and solar energy is used in at least 1 % of all the Czech inhabited dwellings. It also indicates that these renewable energy sources are far more used in detached family houses rather than in apartment houses. Overall, most of the renewable energy sources used in Czech households are in the Central Bohemian Region, the least in Karlovy Vary Region and the capital city of Prague. Although the datasets do not provide enough evidence to derive any reliable development trends, they provide useful information on the minimal distribution of these resources in the past 10 years and also the effect of selected policy instruments to support the use of these resources on Czech households in comparison with the situation before they came into force.

Malá spalovací zařízení na pevná paliva
20.5.2013
Ing. Aleš Bufka, Ministerstvo průmyslu a obchodu

This report is the result of processing all the available statistical sources that relate to the development of small combustion devices supply on the domestic market and its structure. Department of Resources and Energy Statistics acceded to this investigation due to the lack of comprehensive information about the number of devices, and to demand for this type of information.

20.5.2013
Ing. Antonín Lupíšek, doc. Ing. Tomáš Matuška, Ph.D.

The University Centre of Energy Efficient Buildings is a newly established interdisciplinary research institute of Czech Technical University focused to energy efficient buildings having the healthy indoor environment that, at the same time, are environmentally friendly. The main objective for the Centre establishment is the development of technologies for the energy demand reduction and the efficient improvement of natural sources concerning new constructions and reconstructions of existing buildings. The objective is to be achieved by the holistic approach, the expert knowledge concentration from the field of architecture, construction, mechanical engineering, information technologies, and hygiene of indoor environment and the top instrument equipment of the Centre.

13.5.2013
Ing. Miroslav Urban, Ph.D., prof. Ing. Karel Kabele, CSc.

In relation with the implementation of the revised EU Directive 2010/31/EU on the energy performance of buildings are currently changing some of Czech legal regulations and new methodology for energy performance assessment is introduced . This article focuses on an example rating the standard family house with conventional solution of building envelope and technical systems, using the new evaluation method. For this object will be also an obligation to issue an energy performance certificate as required by the Consolidated Act No. 406/2000 Coll., as amended.

Jak funguje net metering
6.5.2013
Mgr. Jiří Zilvar, redakce

Net metering is a way of trading electricity from renewable sources. It also works as an effective incentive to purchase renewable energy source and represents an alternative to other forms of support. In the easiest way it can be described as “turning the meter in both directions”.


zpět na aktuální články
 
 
Reklama