Modernisation and Ecologisation of ČEZ’s Coal Power Plants
ČEZ has desulphurised a total of 6,462 MW of installed capacity. The desulphurisation programme reduced emissions of sulphur dioxide, ash solids, nitrogen oxide and carbon monoxide, compared to levels in the early 1990s.
1990s – PROGRAMME FOR ‘GREENING’ COAL POWER
The main event in recent history of the Czech coal-fired power industry has been the ‘greening’ of power plants, i.e. bringing all coal-fired energy sources into a technical condition that would limit any further destruction to the environment. In 1992–1998, the ČEZ power company implemented probably the largest and quickest environmental and development programme in Europe. Under this programme, CZK 46 billion of direct investments and CZK 65 billion of related investments were channelled into installing 28 desulphurisation units and 7 fluidised bed boilers, upgrading ash separators and modernising power plant control systems at the company’s coal-fired power plants.
ČEZ has desulphurised a total of 6,462 MW of installed capacity. Of this amount, 5,930 MW was desulphurised through flue gas scrubbers (5,710 MW wet limestone scrubber, 220 MW semi-dry lime method), 497 MW was desulphurised by replacing old boilers with modern fluidised bed combustion, and fuel was changed for 35 MW. Along with progress to green the more modern sources of coal, ČEZ also launched a programme to restrict the oldest facilities. Before initiation of the programme to modernise and desulphurise ČEZ’s coal-fired power plants, total installed capacity of this type of plant was 8,482 MW. Under the programme, older coal-fired power plants with a total installed capacity of 2,020 MW were decommissioned.
The desulphurisation programme reduced emissions of sulphur dioxide, ash solids, nitrogen oxide and carbon monoxide by 92%, 95%, 50% and 77%, respectively, compared to levels in the early 1990s. Almost 90% of energy by-products from the desulphurisation process are no longer waste but can be recycled.
Construction of Desulphurisation units in coal power plants
| Power plants | Capacity | Technique | Installed |
|---|---|---|---|
| MVV - wet limestone scrubber, PSV - semi-dry lime method | |||
| Prunéřov 1 | 4 x 110 MW | MVV | December 95 |
| Prunéřov 2 | 5 x 210 MW | MVV | August 96 |
| Počerady | 2 x 200 MW | MVV | November 94 |
| Počerady | 3 x 200 MW | MVV | November 96 |
| Ledvice | 2 x 110 MW | PSV | December 96 |
| Tušimice 2 | 4 x 200 MW | MVV | May 97 |
| Tisová | 100 MW | MVV | November 97 |
| Chvaletice | 2 x 200 MW | MVV | December 97 |
| Chvaletice | 2 x 200 MW | MVV | November 98 |
| Dětmarovice | 4 x 200 MW | MVV | June 98 |
| Mělník | 720 MW | MVV | November 98 |
Construction of fluidised bed boilers
| Power plant | Capacity | Installed |
|---|---|---|
| Tisová | 86 MW | December 95 |
| Hodonín | 60 MW | September 97 |
| Poříčí | 55 MW | October 96 |
| Hodonín | 45 MW | October 97 |
| Tisová | 86 MW | November 97 |
| Ledvice | 110 MW | October 98 |
| Poříčí | 55 MW | September 98 |
Decommissioning of coal power plants
| Power plant | Decommissioned capacity | Decommissioned |
|---|---|---|
| Total | 2020 MW | |
| Prunéřov 1 | 110 MW | January 1991 |
| Tisová 2 | 100 MW | January 1991 |
| Tušimice 1 | 110 MW | January 1991 |
| Prunéřov 1 | 110 MW | January 1992 |
| Tisová 2 | 100 MW | January 1992 |
| Tušimice 1 | 110 MW | January 1992 |
| Hodonín | 55 MW | January 1993 |
| Počerady | 200 MW | January 1994 |
| Ledvice | 110 MW | February 1994 |
| Hodonín | 50 MW | January 1995 |
| Hodonín | 50 MW | August 1996 |
| Tušimice 1 | 110 MW | September 1996 |
| Hodonín | 50 MW | April 1998 |
| Tušimice | 110 MW | April 1998 |
| Tisová | 50 MW | June 1998 |
| Ledvice | 200 MW | December 1998 |
| Poříčí | 55 MW | December 1998 |
| Tušimice 1 | 110 MW | December 1998 |
| Tušimice 1 | 110 MW | December 1998 |
| Mělník 2 | 110 MW | December 1998 |
| Mělník 2 | 110 MW | December 1998 |
21st century – second renewal wave of coal power
Because desulphurisation facilities installed during the first wave of ecologisation had a lifetime of approximately 15 years, and as a result of tightening requirements for coal-fired power plants and concurrent dwindling lignite reserves, ČEZ launched another wave of ecologisation of its coal power plants in the Czech Republic in the latter half of the first decade of 2000s. ČEZ renewed its sources through a combination of replacing obsolete technologies (retrofits), constructing new thermal lignite power plants and executing a controlled and definitive restriction of some technically and morally obsolete units.
This project was unique in the European Union. The ČEZ Group either modified or completely replaced its coal-fired power plant technologies within a relatively short time. Investing a total of approximately CZK 100 billion, no other European Union nation has conducted a project to reduce harmful emissions from electricity generation to such an extent.
By mid-2012, the Tušimice II power plant had been comprehensively overhauled, and updates to the Prunéřov II power plant were complete by summer 2016. All four Tušimice production units, each with a capacity of 200 MW, were fully modernised. The second project involved three of the five production units and increased capacity from 210 to 250 MW. All the modernised units are now fitted with the best available technology for operations. In both cases, the engine rooms, boiler rooms, desulphurisation units, electrical separators and other equipment necessary for operating the power plants were upgraded for another 25 years of use.
Modernisation of the Tušimice plants increased net efficiency from 34% to 39%, effecting savings of about 14% of primary fuel, i.e. coal. At the same time, nitrogen oxide, sulphur dioxide and particulate matter emissions were reduced by 70%, 79% and 87%, respectively.
Modernisation of the Prunéřov II power plant was launched in September 2012, almost immediately after overhauls at Tušimice were completed. Efficiency in combination with heat production at Prunéřov II increased to over 40%, and all emission parameters improved by an average of 60%. Specifically, the results included savings of 15% in primary fuel and reductions of nitrogen oxide, sulphur dioxide and particulate matter emissions by 70%, 80% and 88%, respectively.
The third significant project was construction of a 660 MW supercritical unit in Ledvice. The new source in Ledvice is a highly ecological production unit with supercritical parameters and also one of the most modern conventional power plants in Central Europe.
In the recent past, a biomass analysis laboratory, biomass sorter and transport line for biomass pellets with a conveying capacity of 20 tonnes per hour commenced operation. In January of this year, an automatic biomass sampler also commenced operation.
State-of-the-art technology and the establishment of operating and production parameters in the project decreased all monitored emissions at the Ledvice power plant by an average of 50%.
The ČEZ Group and Ledvice power plant have also been involved in an ornithology conservation programme by ALKA Wildlife, o.p.s. A nest box for falcons has been installed since 2015 on one of the chimney galleries. Every year, a pair of endangered peregrine falcons raise 1–3 chicks.