Local Power Plant Research Articles

Prospects for Using Wind Energy in the Western Sector of the Arctic

The aim of the study is to estimate the wind energy potential in the western sector of the Arctic and to identify possible ways for using wind resources for power and heat supply to regional consumers. The data of long-term wind velocity observation series at meteorological stations in the western sector of the Arctic were processed. Based on the obtained results, a map showing the distribution of annual average wind velocities in the coastal regions of the Barents and White Seas has been drawn; the recurrence of wind velocities has been studied, and the wind energy resources in the region have been estimated. It has been established that in the majority of coastal regions, the annual average wind velocities at a height of 10 m above the ground level are in the range 5 to 8 m/s. The highest wind intensity is observed during the winter months. The seasonal maximum of wind velocities coincides with the maximum demand for heat and electricity in the cold season, which is a favorable prerequisite for successful use of wind energy for meeting the consumers’ electricity and heat supply needs. The presented data testify the possibility of efficiently using wind power plants (WPPs) in the following three main areas: the development of systemic wind energy (operation of large wind farms as part of the power system), participation of WPPs in supplying power to autonomous consumers (joint operation with local diesel power plants), and heat supply to consumers (joint operation with boiler units). Based on the study results, promising sites have been determined for construction of large wind farms on the Kola Peninsula northern coast near the hydroelectric power plants operating as part of the Kola power system. The indicators characterizing possible joint operation of WPPs with local diesel power plants and boiler units in decentralized power supply areas have been obtained. It has been shown that the major effect from using wind energy boils down to saving expensive fossil fuel, which is delivered to consumers in the Arctic regions at high transportation costs. In the areas of decentralized power supply, the use of WPPs helps save from 20 to 70% of annual fuel consumption depending on the wind energy potential.

Automatic detection, classification and localization of defects in large photovoltaic plants using unmanned aerial vehicles (UAV) based infrared (IR) and RGB imaging

This study aims to build a photovoltaic (PV) plant maintenance and operation system, using an unmanned aerial vehicle (UAV) carrying a thermal imager to take images. In the proposed system, the infrared (IR) image was used for detecting PV module thermal defects, and the RGB image was used for detecting module surface defects. The two images were employed to cross validate the causes for module defects.In Part I, the PV plant information pattern was created, and the Taiwan PV plant (1,482 PV modules, 410 kW) was taken as an example. The PV system image feature points were detected by using the Scale Invariant Feature Transform (SIFT), in order to solve the feature variation problems, such as image luminance, rotation, and zoom in/out. The same feature points of multiple local power plant images were matched. Afterwards, the optimal number of feature points was calculated by homography transformation and random sample consensus (RANSAC) to form the PV plant panorama by image stitching. The PV plant panorama background noise was removed by image hue. The module segmentation of PV systems was performed by using image luminance, and the PV module was geometrically reconstructed by using morphology. The PV module edge contour was extracted by the Laplace operator to obtain the perimeter, area, and centroid features. The quantity and positions of PV modules were recognized and calculated to form the PV plant information pattern. In Part II, the PV module defect recognition and classification system was built. The defects in seven PV plants in Taiwan were collected, and the image features were enhanced using a convolutional neural network (CNN). Besides using the convolution layer to capture the image features, Max Pooling and local response normalization were used to enhance the image features. Color space transform was used to intensify the color features, increase the accuracy of the classification modules, and recognize and position the PV module defects. The IR image hot spot recognition accuracy was 100%. The classification accuracy of eight modules, including one normal module and seven defect modules, is 97.52%. The classification accuracy of six modules, including the appearances of one normal module and five defects in RGB images, is 99.17%. The classification accuracy of 14 defects in IR thermal images and RGB images is 97.52%. The causes of defects were cross validated by IR thermal image and RGB image. This study applied the K-fold cross validation to select the optimal model, and the recognition time of one image was shorter than 0.3 s, which is lower than the camera time constant. The results show that the system is applicable to real-time detections. In Part III, the PV plant defect information pattern was created. The PV module with defects was labeled during detection, and the defects in the power plant PV module and the positions thereof were obtained, which would be favorable for PV plant maintenance.

Hybrid photovoltaic‐liquid air energy storage system for deep decarbonization

AbstractNowadays most photovoltaic (PV) plants usually use battery energy storage technology to smooth fluctuant power, but batteries have the drawbacks of a short lifetime and environmental pollution. The existing renewable power networks have serious problems with decarbonizing electricity on the end‐user side. This paper investigates a new hybrid photovoltaic‐liquid air energy storage (PV‐LAES) system to provide solutions for the low‐carbon transition for future power and energy networks. In this article, a local PV power plant cooperates with its maximum power point tracking (MPPT)‐based boost converter, to generate low‐carbon electricity with some uncertain fluctuations. Then a zero‐emission‐air‐based LAES unit is used to absorb the surplus power from the PV plant, and also compensate power for the local load with inadequate power level. This makes the new system save a large proportion of power from main grids, which can also indirectly reduce greenhouse gas emissions. For the MW‐class PV‐LAES case, results show that the surplus renewable electricity (6.73 MWh) generates 27.12 tons of liquid air for energy backups during the day time, and then the LAES unit has a round‐trip efficiency of 47.4% that can discharge a flexible power compensation to the load in the night. Accordingly, the grid power demand reduces significantly from 12.78 to 3.33 MWh in a day. In this way, the annual power savings is estimated to be 3449.25 MWh, and the corresponding carbon emission can be reduced by 2607.63 tons. Regarding the economic performance, the PV‐LAES system presents a dynamic payback period of 9.33 years and an accumulated life‐cycle net profit of $2,260,011. Overall, the proposed PV‐LAES scheme is economically feasible from a life‐cycle perspective, and can potentially realize flexible energy interaction with local renewables to achieve an integrated low‐carbon power generation and storage system.

Comparison of environmental impact on various desalination technologies

The environmental impacts of desalination of saline water were studied by membrane i.e., Reverse Osmosis with Non-Renewable Energy (RONRE), Solar Renewable Energy (ROSRE), and phase change methods i.e., solar thermal systems, including the Waterfall Cascading Distillation with Linear Parabolic through Solar Concentrator (WCDLPC), Distillation with Stand-Alone Point-Focus Parabolic Solar Concentrator (DSPPC), Distillation With Linear Parabolic Concentrator, and Vacuum Pump (DLPCVP). The PVsyst software was used to design a local photovoltaic power plant to supply energy, and SimaPro software (Impact 2002+ method) was used to calculate the environmental indicators. The results showed that electricity consumption in RONRE, photovoltaic panel in ROSRE, WCDLPC and DLPCVP, and iron in DSPPC desalinations methods had the highest effects on the creation of environmental indicators. The highest values of human health, ecosystem quality, climate change, and resources depletion occurred in DSPPC, WCDLPC, RONRE, and RONRE, respectively. It is worth mentioning that the lowest values of these indicators occurred in ROSRE. The results of the final environmental index showed that the highest and lowest final environmental index of 2119.87 μPt and 176.71 μPt were observed in ROSRE and RONRE, respectively. The results indicated that changing the energy from fossil to solar energy form reduces the final environmental index by 91 %.

Physicochemical Properties of Ti3+ Self-Doped TiO2 Loaded on Recycled Fly-Ash Based Zeolites for Degradation of Methyl Orange

The extensive production of coal fly ash by coal combustion is an issue of concern due to its environmental impact. TiO2-zeolite composites were synthesized, at low cost, using recycled coal fly ash from a local thermoelectric power plant to produce the zeolite using the hydrothermal method. TiO2 was loaded by means of the impregnation method using ethanol and titanium isopropoxide between 8.7 and 49.45 wt% TiO2. The samples were characterized by X-ray diffraction, Raman, electron spin resonance, high-resolution transmission electron microscopy, N2 adsorption-desorption, doppler broadening of annihilation radiation, and diffuse reflectance techniques, and the photocatalytic activity of the composites was evaluated according to the degradation of methyl orange under UV light. The results show that TiO2 crystallizes in the anatase phase with a Ti3+ oxidation state, without post-treatment. TiO2 particles were located within the pores of the substrate and on its surface, increasing the surface area of the composites in comparison with that of the substrates. Samples with TiO2 at 8.7 and 25 wt% immobilized on hydroxysodalite show the highest degradation of methyl orange among all studied materials, including the commercial TiO2 Degussa P25 under UV light.

Tackling climate change through circular economy in cities

Circular economy principles can lead to a series of opportunities to tackle climate change, particularly in cities of developing countries where the generation of waste, consumption and demand for energy is growing rapidly. This paper aims to advance the understanding of the expansion of circularity for tackling climate change using biomass for energy at the urban scale. In addition, little is known about how Circular Economy (CE) flows can be quantitatively integrated, what potential trade-offs exist in promoting Circular Economy using biomass, and how governance models can integrate these flows and contribute to a Circular Economy transition in cities. Based on an empirical study of a city in India, where the private sector participation through an innovative Public-Private Partnership (PPP) model enabled the use of urban wastewater in thermal power plants, the study presents the viability of Circular Economy models at the city scale. The feasibility of a further expansion of this circularity by co-firing biomass in local thermal power plants was analyzed, as a potential solution for reducing pollution and carbon emissions in a hard-to-abate sector. The result indicated an average 20.5 MJ kg−1 calorific value for torrefied mixed biomass pellets from crop residues, which, if applied to about 447 kt y−1 surplus biomass available in Nagpur would amount to 9.18 PJ of energy (per year). Overall, local power plants demanded about 19.85 Mt of coal in 2017–18, equivalent to 297.8 PJ in that fiscal year. Thus, the supply of torrefied pellets from peri-urban crop residues can meet between 2 and 3% of the demand from coal-fired power plants, resulting in a 0.3% decrease in the emissions from the power sector in India in 2017–18 (i.e., 922 MtCO2), benefiting different sectors and levels of government. The analysis provides a framework for understanding the technical and institutional possibilities for strengthening the relationship between circular economy and climate change in the cities of developing countries by connecting flows and systems within and beyond urban centers. Therefore, the expansion of Circular Economy in cities can occur by integrating urban sectors and policy coordination at different levels of governance. Partnerships between local governments, utilities, and civil society for co-managing energy, water, and waste in cities can reduce the financial burden on national governments, including meeting national emission targets.

An equilibrium model of NOx emission in gas turbine combustors

In this study, an equilibrium model for NOx emission in gas turbine combustors was developed. The model is based on the governing thermodynamic, materials, and energy balance equations. Results obtained from the model simulation were compared with operational data from a local gas turbine power plant. There was about a 3 to 6 percent deviation for the periods considered. Consequently, the model is reliable in the design of new combustors and in assessing the pollutant emission during operations. It was established that factors that affect NOx formation include flame temperature and quantity of excess air used. Furthermore, the results revealed that the most important parameter that governs the formation of NOx is flame temperature, as the formation of NOx rises exponentially with an increase in the combustor flame temperature.

Occurrence and sources of microplastics and polycyclic aromatic hydrocarbons in surface sediments of Svalbard, Arctic.

Due to the distinct environment condition and geographic location, Svalbard has been recognized as a potential pollution reservoir in the Arctic. In this study, 8 surface sediment samples were collected from two fjords in Svalbard (Kongsfjorden and Rijpfjorden) in 2017, and they were searched for microplastics and polycyclic aromatic hydrocarbons (PAHs). PAHs were also investigated in 10 soil samples of Ny-Ålesund for local anthropogenic source analysis. The level of microplastics and other anthropogenic particles ranged from not detected (ND) to 4.936 particles/kg dry weight (DW). Fiber was the only shape of the microplastics found and three polymers (polyester, rayon and cellulose) were detected, which suggested that fisheries-related debris and textile materials were possible sources of microplastics and anthropogenic particles. For PAHs, the level of ∑26PAH was 9.2ng/g to 67.1ng/g (DW), and were dominated by lnP and BghiP, indicating petroleum combustion source. Further analysis revealed that traffic emissions from cars and diesel combustion from a local power plant were major sources of PAHs in soils of Ny-Alesund, while traffic emissions from ships were the dominate source of PAHs in sediments of Kongsfjorden and Rijpfjorden. A higher level of PAHs was observed in Ny-Alesund, confirming an anthropogenic input, while transport via ocean currents might contribute to the higher abundance of microplastics in Rijpfjorden. Further research and even long-term observation of pollutants are needed to fully understand the pollution status in polar regions.

Bioenergy as an Alternative Energy Source: Progress and Development to Meet the Energy Mix in Indonesia

Government policies in Indonesia have been pushing in the past decade towards 100% electrification target by end of 2020. However, many of the new energy policies are reused from previous policies designed for different objectives causing overlap in policies between the central and local governments. Local distributed generation are not fully controlled by local stakeholders and community, and with the lack of long-term planning, continuous government incentives and support, they are bound to fail due to the lack of maintenance. The use of solid biomass for household has decreased significantly due to the government support for LPG stoves that overtaken other government projects supporting biomass. Small-scale biomass research is showing good progress towards the implementation of novel methods for biomass utilization. However, majority of the medium and large-scale projects are still relying on old technologies such as direct biomass combustion in boilers rather than the more environment friendly gasification technology. Another major biomass contribution to national energy mix is through liquid biofuels. This work summarizes the current and prospective energy mix in Indonesia and the main conventional and non-conventional energy sources and their environmental concerns. This work also gathers the latest local biomass research and biomass power plant projects.

Integrated unit commitment and economic dispatch of combined heat and power system considering heat-power decoupling retrofit of CHP unit

Low-carbon development of a power system is realised via the flexibility retrofit of thermal power units with heat-power decoupling (HPD) of combined heat and power (CHP) units providing the necessary transformation pathway. First, this study examined the primary measures of HPD of CHP units and their impact on unit flexibility. Thereafter, aiming to realise flexibility retrofit of thermal power units, a detailed HPD model on the power side was proposed. In addition, the heat delay and heat loss in the process of heat transmission were also considered, followed by the establishment of a simulation method for unit commitment and economic dispatch (UCED) of CHP system considering HPD. Subsequently, based on IEEE RTS-79 test system, the effectiveness of the model and method proposed in this study was proven. Moreover, the proposed UCED method was applied to systematically analyse the comprehensive benefits achieved via the use of the HPD retrofit of the CHP units. The results showed that HPD retrofit has significant benefits in reducing dispatch costs, enhancing units' flexibility, and promoting wind and solar energy consumption. Finally, combined with the actual power supply and heating in Zhangjiakou, China, the HPD effect in the area was analysed to provide guidance and suggestions for the flexibility retrofit of local thermal power plants.

How much solar PV, wind and biomass energy could be implemented in short-term? A multi-criteria GIS-based approach applied to the province of Jaén, Spain

The progress made in the penetration of renewable energy (RE) sources in most parts of the world is not fast enough for achieving the international climate mitigation targets. Furthermore, there is a lack of energy planning strategies, methods and tools for assessing the implementation of RE technologies which considers the social support. In this work, we present a replicable multi-criteria spatial approach based on geographical information system to estimate the potential of solar photovoltaic (PV), wind and biomass energy technologies that could be implemented in the short-term in a given territory. This potential includes environmental, technical (with economic attributes) and geographical (with social-acceptability attributes) constraints, together with existing local power plants considerations for calculating the electricity generation by technology, and then estimating its jobs creation and greenhouse gas emissions reduction. The approach was applied to the province of Jaén (Southern Spain), which has a pronounced unbalance between its inner electricity production and consumption and apparently is a territory with great technical potential for the aforementioned technologies. Results show that this province has a short-term implementable potential that would annually produce 8.9 TWh from solar PV, 911 GWh from wind energy and 683 GWh from biomass plants; which is 3.8 times greater than the current electricity consumption and would require 1.5% of the total surface of Jaén. This potential can create about 92,800 direct jobs and avoid the emissions of 3.78–8.61 MtCO2 to the atmosphere. The proposed approach can be useful for energy planning processes and for allowing decision-making to accelerate the implementation of RE power plants in order to achieve the climate mitigation goals.

Is China's energy policy effective for power plants? Evidence from the 12th Five-Year Plan energy saving targets

We propose the meta-frontier hybrid data envelopment analysis (MHDEA) model, a non-parametric methodology, to assess the total factor carbon performance index (TCPI) of China's fossil fuel power plants from 2005 to 2015. The model allows for both proportional and non-proportional variables within the production technology. In contrast to conventional DEA models, the MHDEA model simultaneously incorporates the characteristics of group heterogeneity, undesirable outputs as well as hybrid measures. In accordance with the definition of the Malmquist-Luenberger (ML) index, we further explore the driving factors of productivity progress, including efficiency change (EC), best-practice gap change (BPC) and technology gap change (TGC). We employ the difference-in-differences (DID) strategy by combining the variations across regions and years to identify the effect of the 12th Five-Year Plan (FYP) energy saving targets on the TCPI of power plants. Frist, we find that the average TCPI of power plants is 0.50 and the average growth rate is 3.58% per year. Second, the productivity progress of the central group is driven by the innovation effect, while the local group stems from the catch-up effect. Third, the energy intensity reduction target is 1% above the average value and the TCPI is expected to increase by 0.32%. We suggest that the Chinese government design different policies for the central and local power plants based on this heterogenicity.

Recent advances in removal of Congo Red dye by adsorption using an industrial waste

The Congo Red dye was removed from a simulated textile wastewater solution using fly ash from a local power plant. The characterisation of fly ash was studied in detail by SEM, EDX, XRD, FTIR, BET surface area and TGA techniques. The influence of four parameters (contact time, initial concentration, adsorbent dose, and temperature) was analysed, the results showing that the adsorption capacity depends on these parameters. Thermodynamic and regeneration investigations as well are presented. The fit to pseudo-second-order kinetics models suggests that the removal process is a chemical adsorption. The Langmuir model fitted the experimental data, with a maximum adsorption capacity of 22.12 mg/g. The research is a preliminary case study that highlights that fly ash posed a very good potential as a material for Congo Red dye removal.

Future Development of Renewable Energy in Russia: A Case of Solar Power

Currently, there is a growing number of studies related to assessing the cost-effectiveness of renewable energy projects around the world. This topic is also very relevant for the Russian energy market that is otherwise dominated by oil and gas. The Russian Ministry of Energy forecasts that local power plants running on the renewable energy sources (RES) may not become economically efficient until 2025 or later. However, a research question arises: Is it possible to effectively implement RES projects in Russia without any state support? In order to answer this question, the authors need to assess the economic feasibility of seven scenarios for the construction of a solar power plant in the Orenburg region of Russia. The methodological basis of this work is the widely used in the energy sector classic method of investment analysis based on the calculation of discounted indicators: net present value (NPV), payback period (DPP) and internal rate of return (IRR) of the project. All our calculations are based on industry-specific initial capital investment estimates, energy storage equipment costs, and related annual operating costs. This led to the development of the scenarios on the basis of an analysis of the features of electricity and capacity generation in the Orenburg region, the existing options for joining the trading system of the energy market, energy storage applications, as well as the availability of the Russian government support and funding for the solar energy projects. Our results demonstrate that the economic feasibility of the development of renewable energy in Russia can become a reality. Out of the seven scenarios, three yielded the positive economic outcome (among them there were the two project scenarios without government support). These two projects featured the sale of electricity in retail markets and the installation of an additional energy storage system, despite an almost twofold increase in capital investments. The projects in question achieved the best economic results according to the three calculated criteria. In particular, the scenario that provided for the work on the retail market directly to the energy consumer receives an NPV of more than 1.5 times higher than other projects, an IRR of 10% and pays off at least 3 years faster. Achieving a positive economic result in the wholesale market was possible only in case of state support for the project. In addition, this scenario of the project numerically reached almost identical indicators, as in the case of selling energy on the retail market in the region where the power facility operates: NPV is almost 127 million rubles, IRR is within 13.9%, and DPP is 15 years. Other scenarios that do not provide for the use of energy storage systems or do not have state support for working in the wholesale market are not self-sustaining even during the 25-year life of energy equipment. These results might have practical significance and will be used in developing an approach to creating a profile of regions in terms of the advancements of renewable energy, as well as in developing strategies for the incentives of this sector in Russia.

Local energy production scenarios for emissions reduction of pollutants in small-medium ports

Environmental impact produced by ships in ports is a relevant problem, especially when they are located close to urban areas. This paper, taking Ancona (Italy) as a case study, analyzes the CO2 (and other chemical species) emissions produced by the auxiliary engines of ferry ships at berth. Three different configurations have been investigated, one grid-connected and two with local power plants. Cogenerative and photovoltaic scenarios have been considered varying the power size and the presence of a storage system. A computational model, based on maritime traffic and meteorological data over a one-year period, returns the percentages of the energy covered by the plant, the grid and the storage system. Environmental analysis shows that the grid-connected cold ironing scenario reduces the CO2 emissions by 34.5% compared to on-board diesel generators emissions. Cogeneration systems reduce CO2 emissions by 60–62%, while photovoltaic ones around 39%. All scenarios prove to be economically feasible.

Analysis of Drinking Water Treatment Process in The Regional Drinking Water Company of Cahaya Negeri Village

Clean water treatment for the needs of the people of Bengkulu is carried out by several agencies, one of which is managed by The City-Owned Water Company PDAM of Cahaya Negeri Village which is a business entity owned by the local government. This type of study was a qualitative research using interview guidelines and conducting observations. There were 3 informants in this study, namely, the head of the processing unit, the head of the laboratory and the processing operator. The research was conducted in Janaury 2021. The results of the study indicate that PDAM Cahaya Negeri was running well, the processing units were also complete, from maintenance of intake, type of intake pump, coagulation equipment and coagulant material, flocculation building is still very good, sedimentation process is also good, filtration material with silica sand is also appropriate, because the absorption of silica sand is good, and the last is disinfection, using chlorinated material is good for killing bacteria in treated water. The processed water has also met the standard of the Minister of Health Regulation No. 32 of 2017, concerning clean water standards. However, rainfall greatly affects the condition of raw water quality for processing and moreover the local power plant which often shuts down is an obstacle for PDAM CahayaNegeri to carry out processing. It is expected that the PDAM of CahayaNegeri can maintain its achievements and find solutions to its obstacles, in order to meet the need for clean water.

Investigation on Individual and Collective PV Self-Consumption for a Fifth Generation District Heating Network

Renewable Energy Communities have been recently introduced in European legislation to promote distributed generation from renewable energy sources. In fact, they allow to produce and consume energy from shared local power plants. Low temperature district heating and cooling networks with distributed heat pumps have demonstrated their capability to exploit renewable and waste heat sources in the urban environment. Therefore, they are considered a promising infrastructure to help decarbonize the building sector. As their main operating cost is the electricity purchased by the utility for heat pumps and circulation pumps, this work investigates whether a Renewable Energy Community could help mitigate such cost by sharing electricity produced by local photovoltaic (PV) systems. The research relies on computer simulations performed with both physical and statistical models for the evaluation of electrical load profiles at the district level. Results show that due to the different seasonality between heating demand and PV production, the increase in self-consumption due to the distributed heat pumps is lower than 10%. The use of batteries does not seem convenient for the same reason. The environmental benefit of the proposed system is evident, with CO2 emissions reduced by 72–80% compared to the current situation depending on PV power installed. It also emerged that PV sharing significantly improves the self-consumption at the district level, in particular when the installed PV power is limited (+45%). In conclusion, results suggest that current incentives on PV-sharing make Renewable Energy Communities a viable option to improve the techno-economic performance of fifth-generation district heating and cooling networks.

A transparent invasion: a first Mediterranean record and an established population of the glassfish Ambassis dussumieri Cuvier 1828

In this study, we document the first record of the glassfish Ambassis dussumieri in the Mediterranean Sea. Confirmation for taxonomic identity has been conducted using morphological and molecular approaches and was based on a sub-sample of six individuals that were collected from a large school that resides within an artificial protected bay of a local power plant in Tel Aviv, Israel. This unique occurrence of an undisturbed school of invasive species is hereby discussed.

Conservation of the Shaft #1 Headgear at the Tsumeb Mine, Namibia: Corrosion Protection

ABSTRACT The Tsumeb Mine in Namibia represents one of the best-preserved mining sites in the world and is rapidly gaining cross-disciplinary interest among cultural and engineering scientists. Most of the open pit and the shaft mining equipment are still in place, including the ore processing units and the local power plant. The mining area thus deserves recognition as an industrial world heritage site, especially due to the rarity of such locations on the African continent. The Shaft #1 headgear, built in 1924, represents one of the oldest known riveted steel headgears of the Promnitz design worldwide. In contrast to similar steel structures located in the northern hemisphere, it has been exposed to a different rural semi-arid climate since it is located in the Otavi Mountain Land, characterized by semi-annual change of rainy and dry seasons. Parts of the Shaft #1 headgear have remained largely untouched for more than 70 years. Besides its outstanding heritage value, it thus also represents an interesting object for studying the composition of corrosion layers formed on mild steel surfaces when exposed to continental and industrial mining atmospheres. To find a suitable transparent corrosion prevention coating, various on-site coating samples were evaluated after 11 months of outdoor exposure, including Owatrol Oil®, which is based on natural oil and alkyd resin with strong wicking potential. The substance is frequently applied for the conservation of single components but is not yet widely used on large steel structures in the field of industrial heritage conservation. However, it represented the most stable anti-corrosion coating under the local atmospheric conditions in the on-site tests. Thus, the suitability of Owatrol Oil® as a transparent coating for corrosion protection of riveted mild steel structures in such climates was further investigated as a more recent approach for the conservation of large steel structures. Since the protective coatings are exposed to strong UV radiation in the local climate, the addition of a specific UV stabilizer mixture was also tested. For such laboratory tests, two mild steel samples were taken. The first one originated from a diagonal strut of the 1920s and the second one from a handrail mounted in the early 1960s. Using corresponding high-resolution scanning electron microscopy (HR-SEM) and energy-dispersive X-ray spectroscopy (EDX) it was found that the corrosion layers are predominantly composed of lepidocrocite and goethite. A weathering program simulating the specific environmental conditions at Tsumeb in a UV climate chamber was developed and the corrosion resistance of the mild steel surface was subsequently evaluated by potentiodynamic measurements. Such tests proved to be a fast and reliable procedure for ranking the corrosion resistance of the old mild steels. It was found that the long-term corrosion layers already provide significant protection against further corrosion in the simulated environment. However, the study also showed that this can be further improved by the application of the Owatrol Oil® as a protective coating that also seals crevices. The addition of the UV stabilizers, however, led to a significant deterioration in corrosion protection, even in comparison to that of the uncoated long-term corrosion layers on the surface. Regular overcoating seems more advisable for the long-term preservation of the Shaft #1 headgear than modifying the Owatrol Oil® coating with the tested UV-stabilizing additives.

Расчет выработки электроэнергии местной солнечной электростанцией при оптимальных параметрах

Расчет выработки электроэнергии местной солнечной электростанцией при оптимальных параметрах