The ViCTE Newsletter  

Helps professionals keep and improve their English through the Internet since February 2009: Study Technical English and get information about new technologies.

Number 31                                                                                  July 2011

Editorial

 

Giving a definition

In technical texts we often need to give definitions to new or unfamiliar technical terms or vocabulary items and concepts, or to explain ideas specific for the subject that is discussed. Let us consider possible ways of giving definitions or explanations.

  • Some expressions used to define a statement (i.e. a term, concept, idea) are as follows:   means, is taken to be, denotes, refers to, is defined as.    Example – Wind energy penetration refers to the part of electricity produced by wind compared with the total available generation capacity.      OR in an initial position:   by … we mean, by … is meant, in other words, that is (to say).     Example – By load shedding is meant an electrical power outage where electricity delivery is stopped for non-overlapping periods of time over geographical regions.
  •  Another very common method is to give the term being defined and say what it is, i.e. X is/are Y possibly providing some distinctive characteristics.   Examples – Energy demand management (X) is the modification (Y) of consumer demand for energy through various methods such as financial incentives and education.  OR – Energy demand management, also known as demand side management (DSM), is the modification of consumer demand for energy through various methods such as financial incentives and education.
  • One of the most frequent form of a definition is to use two nouns separated by comma.    Example – Transmission networks, a grid system, must already cope with outages of a generation plant and daily changes in electrical demand.

Studying the technical text below please take into consideration these notes and practice them when doing subsequent exercises. Moreover, I recommend drop a look at the text Intermittence of renewables for better understanding the topic. Learn by heart new technical terms and expressions. Doing exercises will help you to memorize them well. Keys to exercises are as usually found in Keys to Newsletters from Number 19 up to Number 31 .

Reference: English for Computer Science by Norma D. Mullen, P. Charles Brown, Oxford English, 1987

Variability and intermittency of wind energy

Electricity generated from wind power is highly variable at several time scales: from hour to hour, daily, and seasonally. Annual variations also exist, but it is not so significant. Like other electricity sources, wind energy must be “scheduled”. Wind power forecasting methods are used, but predictability of a wind plant output remains low for short-term operations.

Icon of Wind Turbines

Image via Wikipedia

 

Since instantaneous electrical generation and consumption must remain in balance to maintain grid stability, this variability causes substantial difficulties when incorporating large amounts of wind power (large penetration) into a grid system. The higher level of wind energy penetration the greater problems arise to incorporate wind power into a grid system.

The wind energy penetration refers to the part of electricity produced by wind compared with the total available generation capacity. There is no generally accepted “maximum” level of wind penetration. The limit for a particular grid depends on the existing generating plants, pricing mechanisms, capacity for storage or demand management, and other factors. Studies have indicated that 20% of the total electricity consumption may be incorporated with tolerable difficulty. These studies have been worked out for locations with geographically dispersed wind farms, or hydropower with storage capacity, demand management, and interconnection to a large grid area export of electricity when needed. Beyond this level, there are few technical limits, but the economic implications become more significant. At present (as of 2010), a few grid systems have penetration of wind energy around 10% or above: Denmark (21%), Spain (16%), Portugal (18%), Germany (9%) and the Republic of Ireland (14%).[3]

Intermittency and the non-dispatchable nature of wind energy production can raise costs for regulation, incremental operating reserve, and require an increase in the already existing energy demand management, load shedding, or storage solutions or system interconnection with high voltage direct current (HVDC) cables. Transmission networks must already cope with outages of generation plant and daily changes in electrical demand. Systems with large wind capacity components may need more spinning reserve (plants operating at less than full load).[[30]

Reference: Wikipedia, the free encyclopedia http://en.wikipedia

Vocabulary

English Russian Czech
demand management регулирование   нагрузки энергосистемы, управление электропотреблением řízení poptávky
economic implications экономические последствия ekonomický  důsledek/dopad
electrical demand потребность в электроэнергии, электрическая нагрузка poptávka po elektřině
financial incentive финансово-материальный стимул finanční  stimul/ podnět
generation capacity объём выработки výrobní kapacita
grid system. объединённая энергосистема, система сетей propojená  elektrizační soustava
HVDC (High Voltage Direct Current) постоянный ток  высокого напряжения stejnosměrný proud vysokého napětí
load shedding сброс нагрузки, снижение нагрузки omezení odběru, odpojení spotřebitelů
non-dispatchable nature неуправляемый  характер (вырабатываемой электроэнергии) neovladatelná povaha,  neřiditelný charakter
non-overlapping periods of time неперекрывающиеся промежутки времени nepřekrývající se časové úseky
operating reserve оперативный резерв мощности operační rezerva
penetration проникновение,   глубина проникновения proniknutí
power outage прекращение электроснабжения výpadek elektrické energie (proudu)
scheduled запланированный, планируемый, плановый plánovaný
spinning reserve вращающийся резерв,  горячий резерв točicí se rezerva
time scale масштаб времени,   шкала времени, временной масштаб časové měřítko, souřadnice času
transmission network передающие сети, магистральная сеть přenosová soustava přenosová síť
     
     

Exercises

 

Exercise 1  Make sentences putting the given words into a correct order (expressions used for giving a definition or explanation are highlighted):

  1. load – By – electricity – stopped – power – we mean – shedding – outage – delivery is – electrical – where – an -.
  2. of – is the – management – demand – energy – modification – consumer -  demand – for – Energy -.
  3. voltage – by the – national – networks – electric – transmission – UK – the high – In the – is meant – grid -.
  4. technology – for  – High – voltage – direct – than – greater – transfer – electricity – refers to – current -  600 km -.
  5. is taken to be – load – plants – Spinning – full – at less – than – reserve – operating -.

Exercise 2  Match technical terms in column X to their explanations in column Y:

  Column X   Column Y
1 Wind energy penetration A is the modification of consumer demand for energy through various methods such as financial incentives and education.
2 Energy demand management, in other words demand side management (DSM), B is the bulk transfer of electricity from generating power plants to substations.
3 High-voltage direct-current technology C means electrical power outage where electricity delivery is stopped for non-overlapping periods of time over geographical regions.
4 Load shedding D denotes the part of electricity produced by wind compared with the total generation capacity.
5 Electric power transmission, in other words high voltage electricity transmission, E refers to  high-voltage direct current (HVDC) electricity transmission systems for the bulk transfer of electrical power.

 

Exercise 3  Make questions to highlighted parts of the sentences below:

  1. By load shedding we mean an electrical power outage where electricity delivery is stopped.
  2. Energy demand management is the modification of consumer demand for energy.
  3. In the UK the national grid  denotes the high voltage electric transmission networks.
  4. High-voltage direct-current technology refers to electricity transfer for very long distances, typically greater than 600 km.
  5. Spinning reserve is taken to be plants operating at less than full load.

 And in conclusion, if you wish to improve your pronunciation and to gain knowledge about giving a good presentation, look at Secrets to Giving a Great Presentation in English. A short description of a situation:

Ken is doing a presentation. He isn’t very comfortable speaking in front of many people. He asks Adriana for some advice.

 

GOOD LUCK!

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