The Stability and Development of the Transmission System – Current Issues

Even though a number of current topics in the Czech electric power system have already been ad-dressed in other parts of the text, the phenomenon of stability and development of the transmission system deserves its own space. The stability of the transmission and, hence, of the distribution system is for the fi eld of the electricity sector simply the key factor, both in terms of a balanced level of production and consumption¹⁸⁵ as well as in a purely technical aspect. Electricity lines and other parts of the power system need to be kept in good condition, which is impossible to achieve without investing in repair, maintenance and developing services. The stability of the transmission network is presently affected by several events, among these the planned completion of the Temelin nuclear power plant, integration of electricity from renewables into the grid as well as the problem of sudden fl uctuations in the grid due to electricity from wind power plants in northern Germany, which at points of overvoltage in Germany fl ow through the Czech Republic. CEPS, as the owner of an exclusive license to run the transmission system, is bound by law to maintain and develop the transmission system.

The Temelin nuclear power plant has 2 x 1,000 MWe of installed capacity. Even though this volume is never sent to the grid in its full capacity, the outgoing clean active power¹⁸⁶ must be coupled with a suf-fi ciently loaded line. The reactive power of one block in Temelin is 19 MWe (the energy efsuf-fi ciency of one block is therefore 98.1 %), operational energy spending amounts to 69 MWe, while in its full operation capacity it truly adds to the network 2 x 912 MWe of active power (see ČEZ, a. s., n.d.b). Presently there are two V051 and V052 lines of 400 kV connected in the Temelin nuclear power plant, aimed at delivering power to the Kocin substation and for potential supply for consumption of its own producing blocks. The outlet from the Kocin substation counts a total of fi ve lines at the voltage level of 400 kV (V476, V475, V432, V473 a V474) and eleven lines at the voltage level of 110 kV (see ČEPS, a. s., 2009). The

trans-185 Consumption is the amount of energy which an electric appliance draws from the electricity grid in order to function. A colour television, for example, consumes 100 W/h, a washing machine 500-2200 W/h, an iron 1,000 W/h, a notebook 40 W/h, a PC with LCD monitor 80 W/h, central air conditioning 3,500 W/h, kettles 2,000 W/h, a vacuum cleaner 1,000 W/h, toasters 1,200 W/h, microwaves 900 W/h, refrigerators 25 W/h and freezers approximately 30 W/h (see Šedivý, 2003).

186 The installed capacity is the maximum theoretically possible capacity of a specifi c system. Reactive power should be excluded from overall installed capacity; since it is power that in reality does not work (it is given by the energy effi ciency of a system). Active power is truly achievable power that can be sent to the grid. In the case of power plants, this capacity is further reduced by the electricity necessary for the functioning of the power plant itself.

mission system in the condition we have had it so far is insuffi cient for maintaining the additional nuclear plant: “If the tender is won by a project proposing 2 x 1,200 MWe, it will prove necessary to connect the 400 kV Kocin substation with the Mirovka 400 kV distribution point with a double 400 kV line and en-hance the connection of the Mirovka 400 kV distribution point to the transmission system by looping the existing Reporyje–Prosenice V413line to this station” (see Cieslar, 2010a, p. 59).

CEPS is obliged to publically release the expected development of the transmission system over the course of a minimum fi ve years. However, as a result of the demanding allocation of investment in infrastructure, CEPS in reality has the plans briefi ng a 15 years development, not only fi ve (see Vnouček, 2010, p. 30). Only the system development for enabling the integration of the new nuclear blocks with 1,200 MWe of capacity requires the investment of 8.08 billion CZK by 2020. Here we cannot but wonder whether the investments associated with the development of the producing portfolio of a private company should be paid by the investor, namely CEZ, and not in any case by end users, especially in regions cov-ered by other companies than CEZ.

Next to investments related to the completion of the Temelin nuclear power plant, CEPS needs to refl ect a number of other changes, among which, for example, the construction of a coal-fi red block in the Ledvice power plant and the Pocerady combined cycle power plant, modernization of the Prunerov II power plant, decommissioning of two blocks of the Detmarovice power plant and the increasing number of applications for connection of electricity plants employing renewables (aside from the photovoltaic sector, for example, wind parks in Krusna hora and Karlove Vary regions).

The entire situation forces CEPS to invest substantial fi nancial assets for maintenance and sustain-ing of a stable grid, whereas the Czech Republic should by 2018 invest 24 billion CZK for development of its transmission system, 2 billion per year for restoration of the existing components by 2016, while CEZ Distribuce, a. s. by 2020 intends to invest 130 billion CZK in the distribution system (see Cieslar, 2009). The need to react to changes of the production electricity base and with that associated expenses is, furthermore, complicated also by complex permit procedures for line constructions, which in the Czech Republic last between 7 and 10.5 years (see table No. 8.10).

Tab. 8.10: The Example of the Construction Process of an Extra High Voltage Line

Activity Duration

Feasibility studies, route location and spatial issues 6–12 months

EIA “Environmental Impact Assessment” Study and public discussions 12–18 months Entry of the routes in the cadastral map (of a local plan), preliminary agreement with

the property owner, preliminary construction project, request and provision of access to the local plans

12 months

Public discussion and addressing objections 6 – 12 months

Agreements with property owners 6 months

Construction Implementation Project 6 months

Designing and construction procedures 12 – 18 months

Purchase of properties 3 – 6 months

Call for tenders, selection of a contractor, including the resolution of other applicants’

objections

The entire process is, in terms of time, enormously demanding, turning into a pretty great problem especially with respect to reaction to renewables’ development. The National Renewable Energy Action Plan of the Czech Republic has sets the goal that the Czech Republic will in 2020 have a power system with 743 MWe of installed capacity in public power plants and 1,695 MWe of installed capacity in pho-tovoltaic power plants (see MPO, 2010e, p. 69). Already by January 1, 2011, there has been, however, 217.8 MWe installed in wind power plants and 1,959.1 MWe in photovoltaic ones. The regulation of the unstable and hard to predict capacity of these power plants will cost the Czech Republic almost 50 billion CZK delivered to CEPS for its ancillary services.

The technical limit of electricity regulation in the Czech Republic is identifi ed, after a total of positive and negative regulation, as amounting to 1,585 MWe during daily regulation and 1,395 MWe during night regulation. According to a study by EGU Brno, a. s., the technical limit will in 2013–2015 reach 2,000 MWe, while the distribution companies show evidence that the sum of potential capacity (based on the issued connection approvals) was by January 31, 2010, 8,063 MWe from renewables (5,277 MWe from photovoltaic plants and 2,786 MWe from wind plants) (see Jabůrková, 2010, p. 320-321).

The Czech Republic has peak and semi-peak electricity regulation plants. Peak power plants are the Orlik wind power plant, Dlouhe strane pumped-storage hydroelectricity, hydropower plants with more than 1 MWe and the Vresova combined cycle power plant. Semi-peak power plants are the Melnik, Prunerov I, Tisova, Chvaletice, Detmarovice and Hodonin power plants (see Růžička, 2009). These sorts of power plants are selected for their capability of a quick change of capacity and quick connection to the grid, as previously described (see comparison in table No. 8.11).

Tab. 8.11: Comparison of Different Types of Power Plant

Type of Power

Nuclear Very low Constant, a low degree of regulation capacity

Tens of minutes 50-66 % Storage problems, it requires its

Wind Potentially low Varying capacity, cannot be regulated, completely

Photovoltaic (Solar

Source: Škoda, 2010; For capacity fi gures, see Štěrba, 2006. Modifi ed by T. Vlček, reprinted with the approval of R. Škoda.

With regard to the planned increase in photovoltaic and wind power plants, we can, therefore, assume that the coming years will see greater production of electricity from wind and photovoltaic facilities than enabled by the current technical regulation limit, without jeopardizing the stability of the power system.

There is generally, for example, a need to increase ancillary services by around 20 % of total capacity installed in wind power plants (see Belyuš, 2009, p. 582).

The whole regulation issue is, moreover, marked by sudden, hardly regulated cross-border fl ows of electricity from Germany, which enters the Czech Republic via the V445 and V446 lines from Röhrsdorf.

The Czech Republic is connected with ten 110 kV, six 220 kV and eleven 440 kV cross-border lines, while in the case of Germany it is four 440 kV lines, two at the north-western and two at the south-western border.

The installed capacity of German wind power plants located in the north in 2009 amounted to approx-imately 23,000 MWe, while it should by 2030 increase by another 30,000 MWe (see Belyuš, 2009, p. 582), which truly means a massive capacity of up to 53 thousand MWe (for comparison, the total installed ca-pacity of the Czech Republic was as of December 31, 2012, 20,520 MWe).

“This problem is far from being the Czech Republic’s concern only, but the production of the wind power plants in northern Germany overloads the lines of system operators in Poland, Slovakia, the Czech Republic, the Netherlands, Belgium, Switzerland, making up in the Czech Republic’s case 1,500 to 1,700 MWe of unexpected fl ows. The main reason is the problem of transmission of produced electricity from northern Germany to users in central and southern parts of Germany” (see Cieslar, 2010c). Germany in this relation lacks 3,600 km of electricity lines (see Neuerer, 2011). A surplus of German electricity from wind, which for technical reasons cannot be supplied to German users, is usually purchased by Russian and Swiss pumped-storage hydropower plants, which in that manner obtain less expensive electricity for pumping water also during the day. In addition to signifi cant expenses associated with power system regulation in the event of a fl ow of wind electricity from Germany, CEPS in the long term (approximately after 2015) plans to modernize and increase the capacity of 400 kV lines, which are the most loaded routes during the transfers from Germany to Austria, while these investments would require more than 3.8 billion CZK. The present model of fi nancial regulation of transmission system operators in the EU is solved separately, i.e.

“there is no possibility of fi nancial compensation for investment stimulated by external conditions and any compensation of fl ows from Germany is, therefore, paid for by the Czech user” (see Belyuš, 2009, p. 582).

Germany is, of course, aware of its problem and it is searching for the means to solve it. Besides the long-term cooperation of transmission system operators, for example, Minister of Industry and Trade, Mar-tin Kocourek, in April 2011 met with his German counterpart, Rainer Bruderle, to set up a working group for coordination of transmission networks development, which will with the greatest likelihood include Poland as well. Aside from this, there is the new Mittelsbüren gas power plant emerging in Germany, which should start running in 2013 with 440 MWe of installed capacity. The security aspect of this power plant is signifi -cant mainly for the German company Gemeinschaftskraftwerk Bremen, which intends with this plant to cov-er fl uctuations of electricity production in local wind powcov-er plants (see “Stabilizace dodávek,” 2011, p. 6).

The Czech Republic is currently building a new regulation plant, specifi cally the Pocerady combined cycle power plant with 838 MWe of capacity (it should undergo a test operation at the end of June 2013).

This power plant will, however, like other new combined cycle plants (Melnik, Mochov, etc., see above) function also as a base load and not only as a regulation reserve. Only one can hardly fi nd an investor to lend money for a new power plant which would be aimed at regulation purposes only. The ratio between invested fi nances and stable income is signifi cantly against the success of such a project.