Renewal of Coal-fired Units
In 2007, CEZ Group launched another wave of environmental upgrades of its coal-fired power plants. This follows the environmental program implemented, at a cost of approximately CZK 50 billion, in the years 1992–1998. The principal objectives of the comprehensive retrofit program are:
- to replace old technologies with new ones (retrofits),
- to build new coal-fired power heating plants,
- to execute a managed, definitive decommissioning of installations that have become obsolete.
The program, with a price tag upwards of CZK 100 billion, is the biggest capital expenditure project in the country’s modern history, and will ensure that the company remains competitive. Should the entire comprehensive retrofit program be implemented, there will be a major reduction in emissions. Compared to 2007 the following reductions in annual emissions are expected:
- nitrogen oxides by 65%,
- sulfur dioxide by 67%,
- solids by 48%,
- CO2 by 30%.
The comprehensive renewal of Tušimice Power Station can serve as an example. In this project, we managed to achieve higher-thandesign efficiency in the generating units, leading to a reduction in the amount of fuel (brown coal) consumed per unit of power output. That, understandably, also reduces the amount of emissions per MWh generated. Tušimice II Power Station saw its net efficiency rating increase from 34% to 39%, which translated into a savings of approximately 14% in primary fuels, i.e. coal. At the same time, emissions figures were slashed: nitrogen oxides by 70%, sulfur dioxide by 79%, and solid particulate emissions by 87%.
Hydro Power Stations and Small-Scale Hydro Power Stations
CEZ Group’s 35 hydro power stations in the Czech Republic account for 14% of total installed capacity. Their share in overall generation volume is 3–4%. The large hydro power stations contribute greatly to the stability of the power system: they can be used to optimize the operation of power heating plants, thereby reducing the amount of fossil fuels needed as well as the amount of resulting greenhouse gas emissions. Smallscale hydro power stations are a renewable source of energy with relatively predictable generation output. Their advantages include open-ended lifespans and a very fast start-up time of 90–150 seconds.
Despite these advantages, regular maintenance is necessary, as well as periodic equipment upgrades. In particular, this means the replacement of major moving parts and mechanical overhauls of most hydro power installations owned by ČEZ. This renewal plan will make it possible, by 2022, to increase output by 60,000 MWh, enough to power over 17,000 homes, and reduce CO2 emissions by roughly 60,000 tons. Other indisputable advantages of the upgrades are that no land use is necessary and the landscape will remain unchanged.
In 2010–2011, overhauls of the following CEZ Group small-scale power stations were either completed or commenced: Kníničky, Pardubice, Vrané nad Vltavou, Slapy.