by Oleksandr Afanasenko | Director Dela Energy Systems
Kyiv, Ukraine (SPX) Dec 12, 2021
The development of solar energy in countries with a limited resource of free land increasingly relies on bringing degraded and technogenically disturbed areas into use. Former agricultural yards, exhausted industrial sites, landfills, and abandoned factories constitute a significant land reserve, while simultaneously creating environmental and urban planning risks. Transforming such areas into sites for the placement of solar power plants (SPP) makes it possible to combine the objectives of the energy transition, land reclamation, and enhancement of the investment attractiveness of regions.
Ukrainian practice in the construction of ground-mounted and solar power stations for own needs demonstrates that, with a sound engineering and organizational approach, even extremely complex sites can be effectively integrated into the energy infrastructure. The project portfolio implemented by the author includes facilities located on former municipal landfills, abandoned vehicle fleet sites, sugar factories, brick production areas, as well as large solar power stations for own needs plants on the roofs and industrial yards of Nestle, MHP, Obolon, and other companies. Most facilities are characterized by non-standard geotechnical conditions, a high density of underground and overhead utilities, tight implementation schedules, and the need for reconstruction of grid infrastructure (the Vysokivska, Beryslavska, and other substations).
The portfolio of implemented projects demonstrates a wide range of scenarios for the redevelopment of problematic areas. A representative example is the ground-mounted PV power plant Tavanska 1 with a capacity of 8,56 MW in Kherson region. The facility is located on the site of a former landfill with soft soils and a significant slope. Implementation of the project required large-scale removal of surface waste, terrain grading, and the use of exclusively crawler machinery for movement over the weak foundation. To prevent erosion and pile undermining, a stormwater drainage system was designed. The scope of work included pile driving operations, laying of cable lines, installation of steel structures, installation of Jinko modules and SMA inverters, and construction of a transformer substation. The plant received a green tariff of 15,03 eurocents and ensured a reduction in electricity withdrawal from public grids by more than 11 000 MWh per year.
The PV power plant Asteria with a capacity of 6,4 MW is located within the service yard of a large farm, where silo pits up to 8 m deep and massive foundations from old buildings were present. To ensure the bearing capacity of the soil, the heaviest tamping rollers available on the market were used, interfering foundations were dismantled, and an innovative access road system resistant to high groundwater levels and loose soils was implemented. A key engineering and organizational solution was the development of a grid connection project with complete reconstruction of the substation Vysokivska, which made it possible to reduce the commissioning time of the plant by three months while maintaining a high level of reliability of the grid infrastructure.
The projects Blahovishchenska (2,72 and 2,86 MW) and Zlatopilska (4,72 and 7,11 MW) were implemented on the territories of a former sugar plant and low-value lands complicated by the need to lay cable lines under highways and through residential areas with a high density of utility networks. For these facilities, technologies of horizontal directional drilling, construction of vertical cable ducts, as well as in-house designs of integrated transformer-inverter substations were applied. This solution not only ensured the technical feasibility of the grid connection, but also increased the green tariff rate by approximately due to optimization of the equipment configuration and minimization of losses.
A special group is formed by solar power stations for its own needs PV power plants on the roofs and industrial yards of the enterprises Nestle, MHP, ECO-BERRY, Obolon. These projects are oriented toward self-consumption and were accompanied by participation in open tenders, coordination of technical solutions with international offices, strict time constraints, and the impossibility of interrupting the continuous production cycle. For rooftop PV power plants, technological solutions were applied that minimize the load on load-bearing structures and increase the non-combustibility class of roofing, as well as layouts for module placement on several dozen roofs, taking into account personnel safety and maintenance logistics. As a result, the enterprises achieved an average annual reduction in electricity consumption from the external grid of 20-35%, which confirms the effectiveness of integrating solar generation into industrial infrastructure.
Comparison of the projects considered makes it possible to conclude that a specific approach to PV plant development is being formed in Ukrainian practice, focused not on the search for ideal sites, but on the technological adaptation of complex territories. Such an approach requires from the design and construction team a high degree of flexibility, readiness to work with non-standard geotechnical conditions and a dense network of infrastructural constraints.
The implemented facilities demonstrate that competent preliminary elaboration of land issues and grid connection often determines the success of the entire project to a greater extent than the choice of a specific equipment line. The use of in-house designs of transformer-inverter substations, optimization of DC and AC connection schemes, as well as well-thought-out logistics of deliveries make it possible not only to meet tight deadlines, but also to obtain additional economic effects in the form of an increased tariff rate or reduced capital expenditures.
Of particular importance is the creation of sustainable models of interaction with grid companies. The substation reconstruction projects Vysokivska and Beryslavska show that active participation of the party interested in connecting a PV plant in the design, equipment supply and construction of substations can significantly accelerate the modernization of grid infrastructure without reducing the reliability of power supply to consumers.
The experience of ground-mounted and solar power stations for own needs plants implemented on former industrial, agricultural and municipal sites confirms that such territories should be viewed not as a problem, but as a resource. Given a clear engineering concept and well-established project management, even a landfill, an abandoned plant or an industrial yard overloaded with utilities can be transformed into a sustainable source of clean energy and long-term income.
The use of degraded and technogenically disturbed areas for facilities that generate solar energy is consistent with global trends in sustainable development and helps reduce land-use conflicts with the agricultural and residential sectors. The Ukrainian feed-in tariff model has created the necessary economic incentives for bringing such sites into use, while advances in pile structure technologies, cable products and inverter equipment ensure the technical feasibility of projects on complex soils and in conditions of high density of utilities.
Analysis of the implemented cases Tavanska 1, Asteria, Blahovishchenska, Zlatopilska and a number of solar power stations for own needs solar power plants showed that a combination of in-depth engineering and geological studies, the use of specialized machinery, innovative methods for laying cable lines, and proprietary designs of transformer-inverter substations makes it possible to successfully implement projects on former landfills, industrial yards, plant sites and areas with a high density of networks. At the same time, the tasks of land reclamation, modernization of grid infrastructure and reduction of energy consumption from public grids by thousands of megawatt-hours per year are being addressed.
The developed set of solutions can be scaled to other regions and countries with comparable conditions. The key success factors are early planning of grid connection schemes, active interaction with grid companies, the investor’s willingness to participate in substation reconstruction, and strict control of construction schedules. The transformation of complex sites into solar generation facilities should be considered an important tool for the post-industrial transformation of territories and for enhancing the energy resilience of industry and municipal infrastructure.
Thus, the aim of the article – to demonstrate the practical feasibility and effectiveness of rehabilitating complex and degraded areas for solar power plants (SPPs) – has been achieved. The experience presented can serve as a reference for developers, engineering companies and industrial consumers considering the implementation of solar generation projects under conditions of limited land and infrastructure resources.
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