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Elektrotechnika
Archiv článků od 3.12.2012 do 24.6.2013

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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.

24.6.2013
Ing. Slavomír Entler

Fusion powered electricity will be an important part of the energy sector in the future. The European Fusion Development Agreement (EFDA) has published a roadmap which outlines how to supply fusion electricity to the grid by 2050. The key facilities of the roadmap are the International Thermonuclear Experimental Reactor ITER and the Demonstration Fusion Power Plant DEMO. The article brings in three parts physical basics of nuclear fusion and fusion technology, a short description of the Czech Republic's participation in fusion research and an overview of the key fusion projects.

10.6.2013
Ing. Vendula Nejedlá, Ing. Veronika Nídlová, Ing. Petr Vaculík, Ph.D., Ing. Jan Hart, Ing. Zdeněk Votruba

The question of reliability and at the same time quality of security systems is the most important criterion for selecting a particular type of security. The most dangerous from this point of view are perimeter systems that virtually in all modifications and technologies are greatly subject to the influence of external conditions and distractions. Due to this fact many false alarms quite often prevents their actual use (at least in civilian areas). This is why we (in the Laboratory of security systems Faculty of Engineering CZU) were searching for a way how to increase the efficiency of employment of the discussed perimeter systems. We wanted to enable problem-free utilization in the commercial area at a moderate price if possible. The solving of the problem by way of minimizing false alarms failed when changed to a different physical principle of detectors. Therefore we chose a different approach – we made a perimeter system with movable and automatic alarm verification.

3.6.2013
Ing. Juraj Krivošík, Ing. Mgr. Michal Staša, konzultant

The lighting research was carried out in 12 European countries in the fall 2012. The research was focused on several lighting aspects in households, ie. the most used types of bulbs (incandescent bulb, compact fluorescent bulb or LED bulb). Also, the location and usage of different types of bulbs and consumer behavior were investigated.

Postup a výsledky kontroly optických prevažovacích prístrojov
13.5.2013
Ing. Ján Ježko, PhD., Katedra geodézie, Stavebná fakulta, STU v Bratislave

Setting out and control of a vertical direction belong among often solved tasks in civil engineering. In order to setting out a plumb line the optical plumbing instruments are used. The most commonly used instrument for this activity is Zeiss PZL (Zeiss Zenitholt PZL 100). This contribution describes the procedure and results of testing according to STN ISO 17123-7: 2010 Optics and optical instruments – Field procedures for testing geodetic and surveying instruments. Part 7: Optical plumbing instruments.

22.4.2013
Mgr. David Hanslian, Mgr. Jiří Hošek, PhD., RNDr. Zuzana Chládová, PhD., Mgr. Lukáš Pop

Other important aspects of wind conditions over the area of the Czech Republic are discussed in the second part of the article. This include the distribution of wind speed and prevailing wind direction, which, can vary significantly between the sites in the Czech Republic.

15.4.2013
Mgr. David Hanslian, Mgr. Jiří Hošek, PhD., RNDr. Zuzana Chládová, PhD., Mgr. Lukáš Pop

While an actual map of the mean wind speed at the height of 100 m above ground (i.e. at the height of state-of-the-art "large" wind turbines) was created and published in 2007 – 2008, only less accurate older data were available for the conditions closer to the ground. This gap is filled by presented article and concurrently published map of the wind speed at the height of 10 m. Furthermore, other important aspects of wind conditions over the area of the Czech Republic are discussed. These results can form a useful tool for those interested in construction of small wind turbines.
To calculate the average wind speed at a height of 10 m above the surface the same procedure and the same input data as for “wind map” at a height of 100 m above the ground were used. The resulting wind map is a synthesis of three calculation models used for long time at the Institute of Atmospheric Physics AS CR: VAS, WAsP and PIAP.

15.4.2013

The European Union is committed to reducing energy consumption in the built environment. Since the heating, ventilation and air conditioning (HVAC) represents approximately 11% of the total electricity consumption in Europe, these systems are an important part of the commitment of the EU. In this article, we discuss two specific aspects of HVAC energy efficiency, both are based on that understanding how the commercial buildings work in real life is the first step towards reducing energy consumption.

Vývoj biometrického identifikačního zařízení
8.4.2013
Ing. Veronika Nídlová, Ing. Jan Hart, Ing. Petr Vaculík, Ph.D.

Today's world is connected with use of computer technology. Of course, there is an increase of security threats that are related to computer and computer networks. It is not just about IT security systems, but in terms of security objects and their parts into which access is restricted whether it be for any reason. Therefore, the user identification is one of the most important parts of the security access systems. To work on the development of functional, reliable and yet not too financially demanding system, is needed to be familiar with existing systems.

1.4.2013
Ing. Bronislav Bechník, Ph.D.

Czech legislation introduced special regime of responsibility and funding of recycling of the photovoltaic modules installed until 2012. The special regime was motivated by the fear that PV modules will remain in the field at the end of life as its owner will go bankrupt controlled.
For every other electronic devices their producers are responsible for recycling since 2005. For photovoltaic modules the producers responsibility in the Czech Republic starts from 2013. For the modules installed until 2012 the owners are responsible for recycling. Before June 30 2013 the owners must enter into contract with a recycling company dedicated to photovoltaic modules recycling, which must be founded by at least four manufacturers of electronic devices (not necessarily photovoltaic modules). The recycling company have to estimate a fee for recycling despite of that no company in the Czech Republic has experience with large-scale recycling of photovoltaic modules. The owners then must pay the fee between 2014 and 2019. Regarding 30-year lifetime of PV modules the recycling will only rarely occur before 2040.
There is no obligation to deposit the collected fees on a blocked account nor another restriction for its use. This implies there is fear the recycling company will go bankrupt controlled. The supposed problem was not solved it was only shifted to another level.

18.3.2013
Dipl.-Ing. Dietmar Staudacher, Fronius Česká republika s.r.o.

So far it was assumed that the PV systems with an east-west orientation need separate inverter for each orientation or at least inverter with two MPP trackers to avoid mismatch losses. Analysis of such system shows that with one MPP tracker losses are relatively small.

Střídač pro fotovoltaickou elektrárnu. Jakou technologii zvolíte?
11.2.2013
Ing. Petr Klimek, Ing. Bronislav Bechník, Ph.D.

Besides the photovoltaic panels, which were already described enough, there are the second major components of photovoltaic plants - inverters. The main parameter for each inverter in terms of energy use is its efficiency. It means how much power from a DC input AC output gets.

Blackout a obnovitelné zdroje energie
28.1.2013
Ing. Bronislav Bechník, Ph.D.

In the past there has been several large blackouts in the world. Risk of such blackout reportedly increases with increasing of share of renewable energy sources in energy mix. In fact neither of previous blackouts were caused by renewables. Main primary causes are age of transmission system components or operator error. Frightening with several days outage caused by renewable sources is exaggerated.

21.1.2013
Ing. Tomáš Maixner, Institut pro rozvoj měst a obcí, IRMO

Czech Technical Standard ČSN EN 12464-1 entered into force on April 1st. This standard is closely related to healthy light. It establishes rules for correct (and healthy) illuminating of workplaces. A number of changes occurred in the standard, small but important. Since the analysis throughout the standard would be impossibly large, I will assume that readers know the "old" version, and I will focus mainly on the kind of changes.

Zdravé světlo – Novela normy ČSN EN 12464-1
14.1.2013
Ing. Tomáš Maixner, Institut pro rozvoj měst a obcí, IRMO

Czech Technical Standard ČSN EN 12464-1 entered into force on April 1st. This standard is closely related to healthy light. It establishes rules for correct (and healthy) illuminating of workplaces. A number of changes occurred in the standard, small but important. Since the analysis throughout the standard would be impossibly large, I will assume that readers know the "old" version, and I will focus mainly on the kind of changes.

31.12.2012
Ing. Tomáš Bartoš, Mgr. Petr Strejček, Ph.D. MBA

Comparison of price developments in eight EU countries shows very interesting facts. Eg. for common Czech household with consumption 2.5-5 MWh / year electricity price increased in 2011 to 229% of the price in 2001. While the same household in Germany to only 115%. While the current price is very close (CR 3.07, Germany 3.50 CZK / kWh).

17.12.2012
Ing. Tomáš Maixner, Institut pro rozvoj měst a obcí, IRMO

Lighting in the school premises is not fundamentally different from the illuminating similar sites in other areas of human endeavor. School classroom is basically a big office. There’s no difference between offices and cabinets, headmaster's office, staffroom. Workshops, laboratories, gymnasiums in the school kitchen and dining room are exactly the same requirements for lighting as in public restaurants. It remains one speciality - school blackboard and its lighting.

Cestovní mapa evropské energetiky 2050
10.12.2012
Ing. Imrich Lencz, DrSc.

The article presents an extensive and detailed analytical study that explores in detail the possibility of directing the development of the European energy industry in order to achieve a significant reduction in greenhouse gas emissions and a significant decarbonisation of the energy sector. Roadmap is not to be predictions or plan for further development, its goals are more modest, to lend a hand in finding their own paths to member countries to a sustainable, economically viable and environmentally acceptable energy economy.

3.12.2012
Ing. Tomáš Maixner, Institut pro rozvoj měst a obcí, IRMO

The irregular series on healthy light can not ignore the amendment of Government Regulation No. 93/2012 Coll. [1], which is valid from April 1 this year. Regulation is dedicated to the protection of health at work and is related to the lighting of course.


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