Stages of project implementation

Thermal power plants are an important element of industrial complexes. The high cost and technical complexity of these facilities impose special requirements on them:

The construction of a thermal power plant is always preceded by numerous administrative procedures, concession permits, land valuation, environmental studies, etc. The implementation of a thermal power plant project includes pre-design work and feasibility studies, design of TPP facilities and equipment, construction and electrical installation works, testing and commissioning. Under the terms of the contract, the contractor provides staff training, operation and maintenance of the thermal power plant.

Modern thermal power plants are complex technical facilities that cost millions of euros. The efficiency of capital investments during the construction of a thermal power plant is laid down at the design stage. Each design solution must be optimal to achieve the customer’s goal. In any case, the optimal solution must meet the quality requirements of the projected facility at the lowest possible cost of materials, financial and labor resources. It needs to be individually tailored to each project.

• Economic viability is assessed based on capital expenditures, construction and operation costs of the facility, and annual expenses for maintenance and servicing.

• Reliability is the ability of the equipment to perform designated functions within specified parameters under certain operating conditions.

• Operational convenience, indicating the minimal number of operations performed by personnel during the day-to-day operation of the equipment.

• Potential for future expansion and modernization of the facility.

A thermal power plant consists of several parts (subsystems), including the technological part, heating networks, electrical, building, hydraulic, transport, and auxiliary facilities. At the design stage, both comprehensive and local optimization of each of the subsystems can be performed.

While the electrical subsystems of different types of thermal power plants have a large number of typical elements and many common or similar design solutions, the technological subsystems of different plants are quite significant.

The design of the technological part of a thermal power plant solves the following tasks: selection of a structural technological scheme (communication between the main units), selection of the main equipment, design of the thermal system, selection of auxiliary technological equipment; design of auxiliary facilities.

The main power equipment of a thermal power plant includes steam generators and turbines. The main equipment should be of the same type, if possible, as this allows for maximum industrialization of construction and optimization of operating and maintenance conditions. The choice of turbines installed at thermal power plants is determined depending on the specific type of facility (COP, ChP) and design.

When choosing auxiliary equipment, the general principles apply:

• equipment performance should ensure long-term operation of the main TPP equipment with nominal power;

• a high level of equipment reliability should reduce the likelihood of unplanned main equipment outages;

• failure to supply auxiliary equipment should not lead to any damage to boilers, turbines, or steam generators.

  Engineers should have the broadest experience in implementing energy projects. They should have the latest information on the latest developments and equipment in project implementation, and use modern means of automation of design work, which speed up the development of technical documentation, and eliminate errors. Each of their decisions is based on their own knowledge, multiplied by advanced technologies.

The stages of construction work are planned individually in each case, depending on the specifics of a particular project. Below is an approximate work plan.

Provide all information about the start of construction works to the interested parties (including local authorities). At the same time, we obtain construction permits and other documentation for the start of construction work.

• Isolation of construction sites using polymer, metal, or wooden fences and other materials to reduce the impact on the landscape, dispersion of material particles, etc.
• Coordination of labor force hiring policies and the search for the necessary number of workers for construction and installation works.
• Installation of informational and warning signs at construction sites, including access roads to construction sites and explosive work zones.
• Organization of a temporary work camp, consisting of office trailers, emergency aid tents, workshops, warehouses, equipment, and material storage.
• Initial stage of earthworks to ensure the safety of the construction site if the power plant construction area is prone to flooding or accumulation of dirt.
• Construction of access roads and roads that will be used for the construction and operation of the power plant (roads for fuel delivery, staff access).
• Execution of basic earthworks, including excavation of excess soil on construction sites and filling these areas with selected material.
• Installation of foundations for structures that require them, such as smokestacks, power generating units, transformer substations, etc.
• Construction of essential facilities, including fuel storage, bunkers, water intake systems, wastewater treatment systems, conveyor belts, etc.
• Construction of auxiliary structures, nodes, and power plant systems, including security systems, video surveillance, remote monitoring, firefighting systems.
• Assembly and testing of control and measuring equipment in the control room.
• Conducting tests on various components, including water intake systems and other equipment (boilers, firefighting systems, conveyors).
• Monitoring fuel and water consumption; adjustment and calibration of main equipment and technological processes of the thermal power station.
• Clearing the area for the power plant ash dump, where the first slag shipments will be received; organizing environmental measures in the ash dump area.

Below is an approximate list of activities to be carried out for each project component. The specific list of activities for each TPP project will differ. Construction of the main equipment of the thermal power plant:

• Boiler room and its equipment.
• Water pretreatment system, including clarifiers.
• Facility for unloading, storage, and processing of fuel.
• Components of the water cooling system.
• Monitoring and safety systems.
• Electrical substation.
• Administrative office.
• Warehouse facilities.
• Workshops. Construction of the water intake system (technical water supply):
• Water intake structures.
• Pump systems and equipment.
• Auxiliary structures.
• Repair workshops.
• Electrical switchgear.

Construction of a storage facility for fuel processing (biomass):

• Biomass storage facility.
• Conveyor belt and shredding equipment.
• Loading and unloading complex for biomass.
• Administrative building.
• Repair workshops.
• Electrical switchgear, etc.

Below is information regarding construction methods, along with a listing of the preliminary conditions necessary for carrying out construction and installation works. Delivery of machinery, equipment, and materials The success of the entire project begins with carefully planned measures for the delivery of all necessary equipment, construction materials, personnel, and other cargoes. The movement of engineering personnel is carried out using light vehicles for activities related to site surveying, project coordination, procurement of goods and services, labor recruitment, and personnel accommodation.

As for the construction works themselves, the use of specialized machinery and equipment is required, such as bulldozers, dump trucks, excavators, graders, vibratory rollers, and so on. At this stage, heavy-duty transport will be needed for the transportation of materials and equipment (concrete, metal structures, prefabricated tower cranes). In some cases, trucks weighing around 50 tons, with a maximum width of over 4 meters, a maximum length of over 15 meters, and a height of over 4.5 meters, may be used. The use of this equipment requires the construction of suitable access roads and may even necessitate obtaining permits from competent authorities. Preparation of the construction site for the power plant During the preparatory stage, the demolition and/or relocation of existing infrastructure objects may be necessary, which could create obstacles for operation or construction.

Preparing a construction site for a thermal power plant

During the preparatory stage, it may be necessary to dismantle and/or relocate existing infrastructure objects that could pose obstacles to the operation or construction of new planned facilities.

The first step to initiate the work is the site breakdown, involving the identification and marking of plot locations. Specialists determine the placement of major components for each facility. The preparation of the construction site involves clearing and leveling the natural landscape, as well as removing the organic soil layer as required. Earthworks, despite being a relatively straightforward stage of construction, must not be simplified or reduced. The construction site surface must strictly adhere to the project specifications, including height variations, slope angles, trench depths, etc.

Remaining soil after excavation is usually applied to level-specific areas of the construction site. Only project-designated materials (sand, gravel) are used for backfilling trenches and pits. Steam turbine installations and other massive equipment are typically installed on sturdy reinforced concrete foundation slabs and pile foundations, the depth of which may reach 20 meters depending on soil conditions. Excavators, dump trucks, bulldozers, compactors, tracked tractors, graders, water tankers, and various construction equipment are used during earthworks.

Point excavations are carried out manually with appropriate equipment and tools. For foundation construction, excavators, concrete mixers, cranes, pile drivers, auxiliary construction equipment, and tools are used. Construction of the power plant’s drainage system is essential to ensure proper rainwater drainage during construction, especially in humid climates. Building the drainage system involves digging temporary trenches around the construction site perimeter to prevent rainwater from entering the work zones.

The main construction and installation works include the erection of buildings and the installation of core equipment such as boilers, generators, water circulation pumps, chimneys, electrical switchgear, transformers, communication systems, etc. This equipment may be manufactured according to project specifications both abroad and in the destination country. It is transported to the site using appropriate freight transport and assembled in specially prepared areas.

Auxiliary facilities for the power plant include the construction of fuel storage and unloading structures, offices, warehouses, repair workshops, vehicle parking lots, equipment refueling stations, auxiliary electrical equipment, sanitary facilities, and water treatment facilities, as well as areas for ash and slag waste storage. Construction and installation works involve the use of various types of cranes, welding equipment, hydraulic jacks, various pneumatic tools, air compressors, drilling and calibration equipment, etc.

Waste disposal information is provided below, including the location of construction waste burial sites and soil extracted during earthworks. The safe disposal and removal of waste are currently of significant environmental importance. During construction works related to the TPP and water intake areas, solid waste in the form of stones, soil, sand, crushed concrete, metal scrap, wood, organic waste, and other debris is generated. Initially, these wastes are stored in the future coal storage and ash dump territory, as these areas are developed last and require minimal work volume. Later, they will be buried or transported for further environmentally compliant disposal by country-specific regulations.

Before commencing operational tests, temporary structures located on the coal storage site will be dismantled. This is necessary for receiving and unloading coal before conducting equipment tests.

The tests include, among other things, the following stages:

• Hydraulic testing of mechanical circuits and water reservoirs.
• Load testing and insulation check of the electrical equipment of the TPP.
• Testing the steam turbine unit under different operating modes.
• Operational testing and sealing of the conveyor belt system.
• Verification of the auxiliary and main cooling systems.
• Inspection of the tightness of seams and connections of steam pipes.
• Hydraulic testing of boilers and other equipment.

After conducting tests, the commissioning procedure for the TPP will begin, consisting of chemical cleaning of boilers, blowing of pipes, checking safety valves, and other tasks preceding the equipment startup for full operation. With positive results from the comprehensive acceptance tests, the thermal power plant can be commercially operated by the contracting company.

If necessary, the engineering company provides training for personnel on equipment operation.

How much does the turnkey construction of a thermal power plant cost? Currently, the construction of a combined cycle thermal power plant costs between 400,000 and 700,000 euros per installed megawatt of capacity. The specific cost is calculated individually and depends on numerous factors and conditions. The overall project cost may vary based on the power plant configuration, equipment used, characteristics of the construction site, cooling method, etc. Labor costs in this case do not significantly impact the budget. The location of the power plant and the terrain of the construction site play a crucial role, in determining transportation costs for equipment and materials, the volume of required earthworks, the cost of building power transmission lines, etc. A significant portion of the investment in a thermal power plant project is allocated to the construction of structures and cooling systems. The cost of installed equipment has little influence on the budget, so careful consideration of technical specifications and the selection of the best available technologies are recommended. Most thermal power plants are currently designed and built under Engineering, Procurement, and Construction (EPC) contracts. While the overall costs may be somewhat higher compared to multi-contract projects, EPC contracting helps businesses save significantly due to a single point of contact. Finally, the cost of constructing a thermal power plant depends on the configuration and capacity. For example, a single 80 MW unit will be cheaper than two power plants with 40 MW each or a single power plant with two small units. At an average price of 550,000 euros per 1 MW of installed capacity, the total construction cost of a 400 MW capacity TPP may be around 220 million euros. The specific cost will depend on the aforementioned factors and the country where construction is planned. It’s also essential to consider that as the installed capacity increases, the cost per MW decreases.

The advantages of EPC contracts in the construction of thermal power plants are evident. From the client’s perspective, this type of contract allows shifting all responsibility for the project to the engineering company, establishing specific deadlines and investment volumes. The high responsibility placed on the EPC contractor sets the highest requirements for participating companies in the tender.