Q & A

Question 1. What decided about the location of the investment in Grudziądz?

In Poland, an uneven distribution of installed power generation sources is observed, with a significant majority of power plants and utility combined heat and power plants located in the south of the country. Above the latitude of 53°N corresponding approximately to the location of Grudziądz there is a small part of the generating capacity of thermal power plants in NPS. This translates into an uneven load on the transmission network. Analysing the operation of the power system after connecting future wind farms with high load variability, it can be seen that most of the existing and planned locations of renewable energy units are situated in the north of the country. For this reason, the implementation of the investment of the Grudziądz Power Plant shall improve the operating conditions of the power system in this part of the country.

CCGT systems are also dedicated to peak operation. In the case of a significant number of RES installations connected to the power grid, this feature of the planned Power Plant may be its additional advantage. Based on the location analyses it was established that the city of Grudziądz, located within the Kujawy-Pomorskie Province, has the greatest potential for implementing the Project, both due to logistics at the construction stage and in terms of the functioning of the target facility. The facility is planned in the southern part of the City of Grudziądz, in the districts of Węgrowo and Pastwisko. This location provides access to both national gas transmission and electricity networks, as well as the rational access to the reservoir/watercourse for the Power plant cooling system.

Question 2. What distinguishes CCGT power plants from other conventional power generation sources?

Combined cycle gas turbine units are a commonly used technology for the production of electricity based on gaseous fuels. Systems of this type allow to meet applicable and future stringent technical and environmental standards set by national and Community legislation. The gas-steam unit that we plan to build in Grudziądz is a compact gas turbine and steam turbine system, characterised by high energy conversion efficiency reaching even over 60 percent. For comparison, the maximum efficiency of high power gas turbines operating in a straight system is a maximum of 42 percent, while of modern coal-fired blocks - 46 percent. The high efficiency will, in turn, save fuel and significantly lower CO2 emissions. An additional advantage of the planned unit is its high flexibility, which means the ability to quickly start and stop the unit, as well as the possibility of dynamic load changes during operation. Such characteristics mean that the unit can dynamically respond to market signals, as well as balance RES installations that are not available power sources, such as wind turbines and photovoltaics. Gas and steam units are also characterised by a high degree of reliability and availability.

Question 3. How does the CCGT unit operate?

A single CCGT unit consists of a gas turbine, recovery boiler and steam turbine. High-methane natural gas type E (GZ-50) is fed into the combustion chamber of the gas turbine or in emergency situations replacement fuel, e.g. light heating oil. The air for the combustion chamber is directed from a compressor mounted on a common shaft with a gas turbine. The exhaust gas, with high pressure and temperature, resulting from the combustion process, drives the turbine. The mechanical energy associated with the rotational movement of the rotor is used to drive the compressor and generator. Due to the fact that the exhaust gas at the gas turbine outlet is at a sufficiently high temperature, the three-pressure recovery boiler "recovers" the thermal energy of exhaust gases for the needs of the steam system. The steam generated in the boiler drives a steam turbine working on a common shaft with a gas turbine and a generator. Thanks to this, it is possible to generate additional electricity and the total efficiency of electricity generation increases from 35 to 40% for a simple gas turbine system, to 55÷60% for a combined gas and steam system. In the combined cycle system, about 2/3 of the electric power is generated in the gas turbine and 1/3 in the steam turbine. About 30% of the heat energy introduced into the system by burning natural gas is received by the cooling system.

Question 4. Why gas as a fuel?

Natural gas is described as a transition fuel in the transformation of the energy sector, today still based mainly on hard (bituminous) coal and lignite, but in the future also on low-carbon and zero-emission technologies, such as renewable energy sources. The characteristic feature of gas fuel and generating installations based on it is low carbon dioxide emission. Currently, the average emissivity determined for the entire Polish manufacturing sector, taking into account both conventional and renewable units, is about 800 kg/MWh. New coal-based ultrasupercritical power generation plants allow obtaining carbon dioxide emission indicators at the level of 700-750 kg/MWh, while in the case of CCGT power plants this indicator is only 350 kg/MWh. The above causes that units of this type will be less burdened with the costs of purchasing CO2 emission allowances. In addition, it should be remembered that new power plants participating in power generation market auctions must have the emissivity below 550 kg/MWh starting from 2020.

Question 5. What conditions decided about the announcement of the tender procedure?

There was a chance to obtain additional, in addition to the sale of electricity, revenue from the implementation of the power capacity service. The results of auctions conducted in 2018 with delivery periods for 2021-2023 prove that the power market is a real stimulus stimulating investment in conventional generation assets. Contracting the CCGT Grudziądz power plant to the power market may significantly strengthen the business justification of the investment. We are currently planning that the project will be put up in a power auction, with the final decision
in which year it will take place would depend on the progress made in the tender procedure.