Distributed Generation Projects Research Articles

PROBLEMS OF GROWTH OF ALTERNATIVE ENERGY SOURCES IN CHINA

The article is devoted to the analysis of the problems of alternative energy in China. Ensuring economic growth is achieved by stable and sufficient supplies of energy to the needs of industry. Geopolitical tensions give rise to the development of national energy resources and, above all, renewable energy sources, development of which has a number of issues. A detailed examination of the 14th Five-Year (2021–2025) Energy Plan revealed challenges to China’s energy goals. Firstly, the main issue of alternative generation is the high level of «losses», i.e. the need to balance energy production with its consumption. The unevenness of energy production throughout the day, the lack of high-power batteries, as well as high-voltage lines for energy transmission, heighten this problem. Secondly, the struggle for land gives rise to competition with agriculture, construction and industrial sectors. Thirdly, alternative energy generation faces the problem of its insufficient efficiency (characterized by the ratio of energy production/ installed capacity, as well as energy density), which leads to reduction in subsidies and the replacement of renewable energy sources with more efficient, but currently less developed reserves of unconventional gas in China. The problem of subsidies is partly solved by the introduction of «green» financing as well as financing from special funds (AIIB, Silk Road Fund, NDB), that allows the implementation of distributed generation projects by attracting investor funds, as well as supporting promising energy production technologies. Most of the shortcomings relate to renewable energy sources, so China is actively developing other areas – nuclear generation, hydrogen production, and optimizing energy flows between inner regions.

Comprehensive Benefit Evaluation of SZ Distributed Photovoltaic Power Generation Project Based on AHP-Matter-Element Extension Model

With the introduction of the “dual carbon goals,” there has been a robust development of distributed photovoltaicpower generation projects in the promotion of their construction. As part of this initiative, a comprehensive and systematicanalysis has been conducted to study the overall benefits of photovoltaic power generation projects. The evaluation processencompasses economic, technical, environmental, and social aspects, providing corresponding analysis methods and datareferences. Furthermore, targeted countermeasures and suggestions are proposed, signifying the research’s importance forthe construction and development of subsequent distributed photovoltaic power generation projects.

A multi-criteria decision-making framework for distributed generation projects investment considering the risk of electricity market trading

Under the background of distributed generation (DG) participating in market trade, the scale of DG has developed rapidly. The investment decision of DG is actually a multi-criteria decision-making (MCDM) problem, nevertheless the current framework rarely considers the risk of market trading. Thus a framework containing scheme attributes and market risks needs to be established. Firstly, an index system including economic benefit, environmental and social benefit and market risk is established. Secondly, subjective and objective weight are combined by using game theory in weighting process. Among them, the subjective weight of each index is determined based on the plus-minus decision-making trial and evaluation laboratory model (plus-minus DEMATEL); the objective weight is determined by the combination of triangular intuitionistic fuzzy number (TIFN) and integrated determination of objective criteria weights (IDOCRIW) model. Finally, the TODIM model is used to rank the alternatives. Taking Shanghai as a case study, the robustness of the proposed framework is verified by sensitivity analysis and comparative analysis. The results show that the weights of index C34 is 0.12, indicating that market participants have a greater influence on market risk. The research will provide an effective tool for investment decision of DG in market trading.

DEVELOPMENT OF DISTRIBUTED GENERATION OF HEAT AND ELECTRIC ENERGY BASED ON EDDY CURRENT GENERATORS-UTILIZERS

The article analyzes ways of transforming Ukraine's energy system based on the "Smart Grid" concept with the implementation of distributed generation projects. The expediency of using new tools for the decentralization of thermal and electrical energy sources as a component of small-scale energy, focused on renewable types of uncertified biofuel of local origin, is substantiated. The energy, economic, ecological and social significance of the introduction of systems of thermochemical destruction of bio-waste with the help of jet-vortex generators-utilizers in energy-intensive technologies has been proven. New approaches to the process of heat energy generation in energy-intensive processes of the agro-industrial complex are proposed using the example of grain drying. Thermal engineering means of thermochemical destruction of biowaste, heat exchange system and disposal of combustion products have been developed. A full cycle of production tests of automated jet-vortex generators-utilizers was carried out, taking into account non-deterministic technological parameters (temperature, humidity, productivity, physico-chemical properties of fuel). The cost of thermal energy in technological processes of grain drying is 5...7 times lower than traditional hydrocarbon. Given the presence of a functional heat exchanger, the drying process takes place with heated clean air, which has a positive effect on the quality indicators of the grain. Taking into account the challenges that exist in the electric power industry of Ukraine, a project of a cogeneration plant based on a generator-utilizer and an air turbine is proposed, which, with the help of a heat exchanger and a compressor, converts part of the thermal energy into mechanical energy. With the help of an electric machine converter, electricity is produced, which meets the needs of the heat engineering module of the installation. The total efficiency of the cogeneration plant is about 80 %.

Impact of increasing transmission capacity for a massive integration of renewable energy on the energy and environmental value of distributed generation

Distributed generation (DG) can offer significant value to power systems by reducing some of the energy and emission marginal costs of centralized generation. These costs can change significantly with the expansion of power systems, especially when renewable energy integration is supported on large new transmission capacity. Accordingly, these cost and price changes could have a potentially large impact on the system value of DG. In this paper, we assess the impact of increasing transmission capacity, for a massive integration of renewable energy, on the energy and environmental system value of solar PV, wind, and energy storage DG. To illustrate this, a case study is presented based on the main Chilean electric power system. We found significant variations in the DG value with different transmission line capacity levels. For instance, just the energy value of PV and storage DG changed up to 43% and 100%, respectively, for line capacity levels growing from 0% (no line) to 200%, in one key transmission line analyzed. This can also represent a strong impact on the revenue of DG projects, generally paid based on this energy value. Furthermore, DG revenue losses can be problematic considering that DG still offers a significant environmental value.

Impact of regulatory changes on economic feasibility of distributed generation solar units in Brazil

In 2019, the Brazilian National Electric Energy Agency proposed that the cost of accessing the electrical grid should be shared among all consumers. This would do away with cross-subsidies, where normal consumers without installed solar distributed generation (DG) units effectively cover the costs of access to the grid for consumers with DG units. The economic viability of the two scenarios were compared, one before and the other after the proposed changes, to understand how this legislature will affect the viability of DG projects. This was achieved by studying all five geographic regions covering the entire Brazilian territory by analyzing data on average solar radiation, demand, and energy prices. After the proposed rule changes, in the general Brazilian scenario, the net present value (NPV) had a reduction of 39.74% and internal rate of return of 26.85%, while the worst happened with Discounted Payback, which rose 52.89%. Stochastic analysis was conducted by varying the investment costs, demand, and energy prices for the solar DG units. The probability of NPV greater than zero was reduced by 2.41% on average after rule changes. Lastly, a stochastic analysis for the national scenario by varying the discount rate was conducted, and a positive NPV probability of 79.60% was found. The study indicates that there is a statistically significant reduction in economic viability for solar DG units when the new regulation proposed is enacted, while the payback period is increased, and other financial indicators are reduced in all analyzed regions. It was confirmed that solar radiation is not the decisive factor in determining the economic viability of solar DG production.

Combining Value-Focused Thinking and PROMETHEE Techniques for Selecting a Portfolio of Distributed Energy Generation Projects in the Brazilian Electricity Sector

This article aims to propose a multi-criteria model to support decision-making from a portfolio in selecting technologies for Distributed Generation of Energy (DGE) projects based on the characteristics of the geographic space in Brazil. The decision model involves using multi-criteria to support the evaluation, prioritization, and selection of projects under a multistage decision-making process that fits into a strategic management cycle within the energy sector of Mato Grosso do Sul (Brazil). The over-classification techniques Preference Ranking Organization Technique for Enrichment Evaluations (PROMETHEE) II and V were applied under the Value-Focused Thinking (VFT) approach, reflecting the decision-maker or manager preferences among several conflicting criteria in the investment context of sustainable distributed energy generation projects. Based on real data, a numerical application is employed to view the steps of this decision model and illustrate the adequacy and effectiveness in practical issues of portfolio management.

Comprehensive Benefit Analysis of Distributed Power Grid Connection

Distributed generation can not only improve the utilization level of energy, but also bring huge economic and environmental benefits, which is conducive to the sustainable development of economy and society [1]. With the expansion of distributed generation scale and the implementation of market-oriented trading pilot, it is necessary to accurately evaluate and analyze the economic and environmental benefits of distributed generation, so it is necessary to establish an accurate evaluation model to guide grid companies and government departments to better develop and utilize distributed generation technology. As a whole, the connection between distributed generation and large power grid is helpful to save investment, reduce energy loss and give full play to their respective advantages. From the perspective of distributed generation project, it is helpful for investors to construct cost, invest reasonably and quote accurately. The benefits of distributed generation access to power grid mainly include reducing line loss, reducing power construction cost, reducing electricity price, delaying the construction of distribution and transmission cost, and improving environment and climate.

Reliability Assessment of Electric Power System with Distributed Generation Facilities

Modern power supply systems that have distributed generation and are connected to the electric power system, renewable energy sources, and storage devices, require changes in the assessment of their reliability indices. The complexity of the energy, technological, and organizational structures of power systems with distributed generation does not allow the traditional concept of "failure" to be used to assess their reliability. Many technological solutions used in the distributed generation projects can become sources of vulnerabilities in the infrastructure of an intelligent electrical network. The study shows that power systems with distributed generation are the structures with overlapping service areas, which determines their specific features represented by an integral characteristic - efficiency. It characterizes the extent to which the use of distributed generation facilities in various operating conditions is feasible. The paper proposes an approach to quantifying the efficiency of such systems. The presented examples demonstrate the calculation of relatively simple power systems with the distributed generation that perform several tasks simultaneously.

A model for measuring the success of distributed small-scale photovoltaic systems projects

Small-scale Distributed Generation through photovoltaic technology is promising, driven by government policies and lower component prices. However, the large amount to be invested, the characteristics of photovoltaic energy, and the uncertainties regarding this technology make it difficult to secure the investment decision and to visualize the success potentiality. Our objective is to propose a success measurement model for the small-scale distributed generation projects' implementation of photovoltaic energy. The methodological approach to modeling encompasses the concepts of Key Performance Indicators and Multicriteria Decision Analysis based on Analytic Hierarchy Process. We researched with 19 experts (researchers) and 32 investors in photovoltaic energy. The model made it possible to weigh the indicators and measure the projects' success under evaluation. Of the projects diagnosed, 15 achieved a Global Success Index of over 76%, considered “Full Success” and 17 were judged as “Potential Success”. We identified that improvement in some Key Performance Indicators could advance to “Full Success” level projects framed as “Potential Success”. Thus, the model contributes to reflection and learning, given our indicators analysis. The main contribution we highlight is the measurement approach developed for the model serving to generate new measurement models. Such models may incorporate other themes, contextual factors, and considerations different from those performed in this case. Applying this model to future projects can provide consistent decisions or make robust new small-scale photovoltaic projects.

A Techno-Economic Approach for Increasing the Connectivity of Photovoltaic Distributed Generators

High penetration of distributed generation (DG) results in technical problems as voltage rise, voltage unbalance, substation reverse power, and transformer overloading. These problems adversely affect the connectivity of DGs either in the planning stage by decreasing the number of connected DGs, or in the operation stage by applying DGs' active power curtailment (APC). This paper presents a techno-economic approach for the enhancement of photovoltaic (PV) DGs connectivity. The proposed approach first employs a probabilistic economic technique for determining the non-curtailable portion of the PV DG power that ensures profitable DG investment. This portion is integrated, as an economic constraint, in the planning phase of the proposed approach that aims to maximize the number of PV DGs connected to the system. In the operation phase, the proposed approach utilizes the capabilities of the existing equipment on the system, i.e., regulators, capacitors, DGs reactive power, and DGs APC to mitigate all technical problems. The overall objective of this stage is to minimize the total DGs APC while fulfilling all technical and economic constraints. The proposed approach is tested on the modified IEEE 123-bus feeder. The results clarify the efficiency of the proposed techniques in increasing the connectivity of PV DGs while maintaining profitable DG project.

Integrated project of a smart microgrid allied with energy management: An initiative to reduce electrical energy costs

Abstract Electricity is undoubtedly one of the most important resources in the modern world. As the demand for electric energy increases, conventional resources that are transformed into electric energy are being exhausted, generating a need to search for alternative sources, resulting in a significant increase in energy costs. This study presents an integrated project of an intelligent microgrid and energy management aimed at reducing energy costs. At the Federal University of Parana (UFPR), electricity represents an annual cost of over BRL 13 million, which is the third largest operating expense of the university. In addition, the public education budget in Brazil has been decreased in recent years. Therefore, this study was conducted within the scope of UFPR and aimed to analyze three alternatives to reduce electric energy costs: i) demand management through an analysis of energy bills, ii) migration to the free energy market, and iii) the development of an in-house photovoltaic generation facility. A computational tool to optimize the contracted demand and simulate the annual savings with the free market and distributed generation projects was developed using Microsoft Excel. Payback, the net present value, and the internal rate of return were calculated. Finally, the economic viability of all alternatives was proven, with demand management demonstrating an economic potential of greater than BRL 500,000 per year, use of the free market saving more than BRL 300,000, and the developed in-house photovoltaic generation system achieving an economic impact of more than BRL 600,000 per year.

Co-construction of energy solutions: Lessons learned from experiences in Chile

The Energy Center has developed a co-construction methodology to address the challenges of technology transfer-based on distributed generation projects- in the context of energy transitions in isolated locations. Based on the experiences developed between 2010 and 2017, this paper analyses the process of preparing the Co-construction methodology. New tools were identified under the light of a theoretical-methodological reflection and a new version of co-construction methodology is proposed from this discussion. This learning process combines academic research and applied projects. It has provided Energy Center with an improved set of tools for current projects, and also contributed to a theoretical-methodological discussion based on new research activities. The main problems of method faced are presented during interdisciplinary work, such as: common understanding of fundamental concepts (sustainability, participation, community); the domination of one discipline over the others; the different visions of the priorities within the same project. And those problems given by the participation process under the paradox of “framing-overflowing”, where the constraints of actual projects (deadlines, budget, and specific KPIs) could limit the possibility of performing in depth diagnostics and building trust. One of the main challenges identified is that an actual impact on the overall experience is only feasible if lessons can be translated into concrete products (best practices, guidelines, tools), so can be adopted by future project developers.

Local network credits and local electricity trading: Results of virtual trials and the policy implications

Current charging methods for network infrastructure and recompense for distributed energy may not result in optimum system solutions. Once feed-in tariffs to support the development of renewable generation are phased out, the payment for grid exports is usually based on the wholesale energy value alone. Network charges are generally levied in full, with few attempts to offer a partial charge, or completely waived. Local Electricity Trading (LET) and Local Network Credits (LNCs) offer one approach to reforming charge structures. This paper examines the effects of LET and LNC on different stakeholders in four virtual trials of medium scale distributed generation projects around Australia, and the implications for policy. The trials found the large value gap between behind the meter systems and grid exports may lead to duplication of network assets, inefficient sizing and operation of distributed generators, and a lack of incentive for dispatchable generators to operate at peak times. The trials indicated that in most circumstances, the combination of LNC and LET addresses all four problems identified to some degree.

Post evaluation of distributed energy generation combining the attribute hierarchical model and matter-element extension theory

Abstract Distributed energy supply has a prominent impact on solving the contradiction between energy supply and demand, environmental degradation, and other issues. This paper analyzes the application of distributed energy supply for specific power projects. We developed a systematic post project evaluation index and evaluation model using the theory of matter-element extension, and determined weights for all indicators that influenced distributed energy generation projects, combined with the attribute hierarchical model. The proposed model was verified experimentally, and shown to enhance evaluation of distributed generation projects. In addition, (1) Distributed energy systems have been widely applied across the world due to their inherent advantages of flexibility, convenience, environmentally friendliness, and high reliability, so it is necessary to study. (2) This paper combined the matter-element extension theory (MEET) and the attribute hierarchical model (AHM) to develop an evaluation model for distributed generation projects. The proposed model was verified experimentally using actual distributed energy project data. (3) This paper enhances the evaluation theoretical research on the post-evaluation of distributed generation projects and capturing experience and lessons for subsequent projects.

Dynamic subsidy model of photovoltaic distributed generation in China

Abstract The differences in resources between regions and the environmental benefit are not currently considered in the subsidy policy on the photovoltaic distributed generation in China. To promote a further development of distributed generation, this paper establishes dynamic subsidy models for photovoltaic distributed generation from the aspect of the emission reduction benefit, based on a dynamic generation cost simulation, which is combined with the learning curve of cost. For projects that their internal rate of return does not reach the basic rate, a certain proportion of the initial investment subsidy will be provided. The calculated results show that with the gradual progress of photovoltaic power generation technology, the emission reduction benefit subsidy will be reduced with the reduction of unit cost. Moreover, factors such as the resources level, the proportion of generation internal consumption by the project and subsidies, all have an important impact on the internal rate of return of photovoltaic distributed generation projects.

Life Cycle Energy Consumption and Greenhouse Gas Emissions Analysis of Natural Gas-Based Distributed Generation Projects in China

In this paper, we used the life-cycle analysis (LCA) method to evaluate the energy consumption and greenhouse gas (GHG) emissions of natural gas (NG) distributed generation (DG) projects in China. We took the China Resources Snow Breweries (CRSB) NG DG project in Sichuan province of China as a base scenario and compared its life cycle energy consumption and GHG emissions performance against five further scenarios. We found the CRSB DG project (all energy input is NG) can reduce GHG emissions by 22%, but increase energy consumption by 12% relative to the scenario, using coal combined with grid electricity as an energy input. The LCA also indicated that the CRSB project can save 24% of energy and reduce GHG emissions by 48% relative to the all-coal scenario. The studied NG-based DG project presents major GHG emissions reduction advantages over the traditional centralized energy system. Moreover, this reduction of energy consumption and GHG emissions can be expanded if the extra electricity from the DG project can be supplied to the public grid. The action of combining renewable energy into the NG DG system can also strengthen the dual merit of energy conservation and GHG emissions reduction. The marginal CO2 abatement cost of the studied project is about 51 USD/ton CO2 equivalent, which is relatively low. Policymakers are recommended to support NG DG technology development and application in China and globally to boost NG utilization and control GHG emissions.

Using proxies to calculate the carbon impact of investment into electricity network assets

Replacement and upgrading of assets in the electricity network requires financial investment for the distribution and transmission utilities. The replacement and upgrading of network assets also represents an emissions impact due to the carbon embodied in the materials used to manufacture network assets. This paper uses investment and asset data for the GB system for 2015–2023 to assess the suitability of using a proxy with peak demand data and network investment data to calculate the carbon impacts of network investments. The proxies are calculated on a regional basis and applied to calculate the embodied carbon associated with current network assets by DNO region. The proxies are also applied to peak demand data across the 2015–2023 period to estimate the expected levels of embodied carbon that will be associated with network investment during this period. The suitability of these proxies in different contexts are then discussed, along with initial scenario analysis to calculate the impact of avoiding or deferring network investments through distributed generation projects. The proxies were found to be effective in estimating the total embodied carbon of electricity system investment in order to compare investment strategies in different regions of the GB network.

The implementation of capital budgeting analysis for distributed generation allocation problems

For the last 7 years, the Republic of Croatia has been witnessing a sudden increase of distributed energy resources connecting to its power system. However, a significant problem is how to find the financial equilibrium which will satisfy the independent power producers on one side and the distribution system operator on the other. In this paper, the authors discuss the capital budgeting analysis of distributed generation projects with a goal of maximizing their net present values. The evaluation of net present values will be the central tool for finding the optimal position and size of distributed generation units in the network. By simultaneously minimizing active power losses the interests of distribution system operator will not be neglected in this study. The power production of distributed generation and power consumption of network loads will be modeled with characteristic average daily power curves with discrete hour intervals. The problem will be solved using genetic algorithm, and realized in Matlab programming environment.

The tidal energy potential of the Manukau Harbour, New Zealand

A renewable source of electricity generated near the demand in Auckland might help defer investment in grid infrastructure, avoid grid transmission losses and help achieve the target for renewable energy mix in New Zealand. The tidal energy at both ends of the entrance channel to the Manukau Harbour is calculated based on navigation chart current speed data. Calculation is done using the kinetic energy flux method, and a farm method calculation is used for comparison purposes.The peak current speeds are modest: 1.35 and 1.80m/s. These give estimated extracted electricity results of 7.2 and 7.9GWh/year for flux method and 13.3 and 11.2 GWh/year for farm method. This electricity could supply about 900–1400 New Zealand homes and is similar to the generation output of a small wind farm. Factors affecting feasibility for a future tidal energy project in the Manukau Harbour include New Zealand electricity demand changes, technology maturity, and environmental effects – especially on rare dolphins. The study concludes that the resource is sufficient to support a small-scale distributed generation project after technology costs reduce. A strong case is made for investment in another more detailed study in 2017.