Cable Cost Research Articles

A bi‐level optimization model and improved algorithm for wind farm layout

AbstractWind farm can obtain the maximize profit by optimizing micro‐locations and cables. The factors that affect profit include the power output of wind turbines, cost and et al., where power output is affected by wake effect, cable cost is related to the length and type of collector cable. The profit is calculated on the premise that the costs and power loss of collector cable are determined. Obviously, there is a hierarchical relationship between the above problems. Therefore, a bi‐level optimization model with constraints is constructed in this paper, where the upper‐level objective function is the maximum profit, and the lower‐level objective functions are consists of minimum the cable cost and the power loss of collector cable; Moreover, an improved algorithm (IDEDA), based on differential evolution and Dijkstra, is used to optimize above model; Finally, simulation experiments are carried out for IDEDA and four algorithms for two different wind conditions, and the results show that IDEDA performs better compared to the other four algorithms in terms of profit and cable cost.

A novel integrated optimization method of micrositing and cable routing for offshore wind farms

In traditional wind farm planning, the design of wind turbine locations and cable layouts is usually undertaken sequentially. However, this approach may potentially result in suboptimal solutions. While the increased spacing between wind turbines enhances power output by reducing wake losses, it also imposes a negative impact by raising cable costs. Addressing this challenge, we propose a novel multi-objective optimization model that simultaneously considers the micrositing of wind turbines and cable routing. A joint framework of the Non-dominated Sorting Genetic Algorithm II (NSGA-II) and the Mixed-Integer Linear Programming (MILP) is established to optimize the layout of wind turbine locations, points of connection, and cable paths. The results indicate that, compared to the traditional sequential optimization, our integrated optimization exhibits significant economic advantages since improved the balance between micro siting and cable routing. By strategically sacrificing a portion of power generation to reduce cable costs, the overall investment profitability can be remarkably improved, with a maximum gain equivalent to 10.02 % of the cable costs.

A platform to study defect-induced behavior in high-temperature superconductor cables

High-temperature superconductor (HTS) cables and magnets are enabling a range of high-current and high-field applications, including compact fusion devices aiming to achieve net energy. Defects in HTS pose manufacturing, cost, and operational challenges. A rigorous understanding and predictive capability for defect-induced behavior at relevant scale has not been established. To address this shortcoming, we have developed a cable-level defect characterization experimental platform coupled to high-fidelity computational modeling. The cable ( Ic∼ 438 A at 77.4 K, self-field) comprises a non-twisted 70 cm-long copper former containing a soldered stack of five rare-earth barium copper oxide (REBCO) tapes (each with Ic = 115.7 A/4 mm-w at 77.4 K, self-field), which can contain a variety of induced defects. Spatially-resolved electric fields are measured with a high-density voltage tap array and absolute current distribution with six custom-wound embedded Rogowski coils. 3D circuit modeling uses nodal analysis and self-consistently accounts for the magnetic field dependence of critical current. The model successfully predicts the experimentally measured spatial and operating current dependencies of electric field and current distribution with no defects, one defect, and two defects, validating the defect characterization platform as a tool for improving the design, cost, fabrication, and operation of REBCO cables.

A hybrid multi-agent metaheuristic for the offshore wind farm cable routing problem

A crucial task concerning offshore wind farm designs is connecting previously placed turbines to a substation, such that the total cable cost is minimal. An NP-hard optimization problem named Wind Farm Cable Routing Problem (WFCRP) models this task. Previous studies have proposed Mixed Integer Linear Programming formulations (MILP) and metaheuristics for the WFCRP. However, they faced difficulties in solving instances with many turbines. Hybridization is a widely-explored approach that has produced better solutions as it combines the best features of individual algorithms. This paper proposes a hybrid algorithm for the WFCRP that combines four state-of-the-art metaheuristics and a MILP formulation. The hybridization technique uses multi-agent and Particle Swarm Optimization concepts, where particles are cooperative agents that work together to find high-quality solutions. Experimental results on instances with up to 120 turbines show that the proposed hybrid algorithm outperforms the best algorithm from the WFCRP literature.

Corrosion Monitoring by Plastic Optic Fiber Sensor Using Bi-Directional Light Transmission.

In this paper, a new sensor is proposed to efficiently gather crucial information on corrosion phenomena and their progression within steel components. Fabricated with plastic optical fibers (POF), the sensor can detect corrosion-induced physical changes in the appearance of monitoring points within the steel material. Additionally, the new sensor incorporates an innovative structure that efficiently utilizes bi-directional optical transmission in the POF, simplifying the installation procedure and reducing the total cost of the POF cables by as much as 50% when monitoring multiple points. Furthermore, an extremely compact dummy sensor with the length of 5 mm and a diameter of 2.2 mm for corrosion-depth detection was introduced, and its functionality was validated through experiments. This paper outlines the concept and fundamental structure of the proposed sensor; analyzes the results of various experiments; and discusses its effectiveness, prospects, and economic advantages.

Feasibility of high temperature superconducting cables for energy harvesting in large space-based solar power satellite applications: Electromagnetic, thermal and cost considerations

The aim of this paper is to present feasibility of application of High Temperature Superconducting (HTS) cables for Space-Based Solar Power (SBSP) application. SBSP is a promising technology that can deliver an infinite amount of clean and eco-friendly energy to the Earth. To deliver the harvested solar energy to the power systems on Earth, efficient energy transmission is critically important. To address the challenges of conventional transmission means, an ideal solution would be using HTS cables. In this research, the design procedure of a Direct Current (DC) HTS cable considering electromagnetic, thermal, and cost constraints is presented. The study considered a 2 MW bipolar DC HTS cable in five operational temperatures: 20 K, 30 K, 50 K, 65 K, and 77 K. The results were showed that the cost and weight of the designed HTS cables were increased by operational temperature increase. However, the cooling cost of HTS cable in higher temperatures, was less than lower temperatures. Also, the total efficiency of the HTS cable and cooling system were increased, when operational temperatures were changed from 20 K to 77 K, from 99.70% to 99.97%, respectively.

METHOD OF EVALUATION THE EFFICIENCY OF FIBER-OPTIC CABLES MODELS WITH MULTI-MODULAR DESIGN BASED ON MASS AND DIMENSIONAL INDICATORS

Context. Today, the leading cable production plants in many countries of the world manufacture single- and multi-module designs of fiber-optic cables (FOC) with different protective covers and the number of fibers. This creates a wide range of possible FOC models for different consumer (buyer) requirements. However, the lack of openness of prices for FOC for the consumer, in particular for the project organization, and the desire of the manufacturer to save on production creates a need for the development and research of a method for evaluating the effectiveness of FOC of a multi-module design. In the work, it is proposed to do this by analyzing a number of optical cable models according to parameters-criteria – the compactness coefficient and the economic efficiency coefficient of the FOC by diameter. Objective. To develop a method of evaluation the efficiency of fiber-optic cables models with multi-modular design based on mass-dimensional indicators, which will allow to quickly choose an appropriate model of the FOC with the given initial data. Method. A method of evaluating the efficiency of the FOC modular design has been developed and proposed. It is based on the comparison of cable models and the selection of the most appropriate of them at given initial data. The paper proposed and introduced parameters-criteria for this – the compactness coefficient υ and the efficiency coefficient according to the diameter of the cable E0 – which show the connection of the design characteristics of the FOC to a certain parameter of its structure. At the same time, the most effective model (design) of the FOC compared to the basic models in terms of technical conditions, both from the point of view of the manufacturer and the customer, consists in lower material costs for its production while simultaneously ensuring the specified requirements for the cable (first of all, number of fibers and mechanical strength). This will allow, at the stage of cable design, to make an appropriate choice of its model with given initial parameters and to develop such a design of the FOC, which will allow to minimize the dimensions (and therefore the material capacity and cost) of the model without losing its quantitative and qualitative characteristics. Results. The paper presents the results of the development and research of the method of evaluating the efficiency of the FOC with multi-module structure based on mass and dimensional indicators. For example, using the developed method, it is shown that it is possible to choose a FOC model with a diameter smaller by 10.9% and save 15.5% of the cable cost for each kilometer of the fiber optic communication line while ensuring the initial requirements for the cable. Conclusions. The scientific novelty of the work results is that, method of evaluation the efficiency of a modular FOC design has been first developed, which allows at the cable design stage to compare the model with the cable design according to the technical conditions (TC) and the appropriate choice of this model with the given initial parameters. The practical significance lies in the possibility of using this method to make an accelerated selection of the cable model at the stage of its design, while simultaneously providing the necessary capacity of the FOC with optical fibers and minimizing the cost of its materials and dimensions.

Wind Farm Layout Optimization Subject to Cable Cost, Hub Height, and a Feasible 3D Gaussian Wake Model Implementation

We address the Wind Farm Layout Optimization (WFLO) problem and tackle the optimal placement of several turbines within a specific (wind farm) area by incorporating additional aspects of an economically driven target function. With this, we contribute three refinements for WFLO research: First, while many research contributions optimize the turbines’ locations subject to maximum energy production or energy efficiency, we instead pursue a strategy of maximizing a profit objective. This enables us to incorporate inner-farm wiring costs (underground cable installation). For this, we explore the impact of using MSTs (Minimum Spanning Trees) and adding junction (so-called “Steiner”) points to the terrain plane. Second, while most research focuses on finding optimal x and y coordinates (i.e., address two-dimensional turbine placement), we also optimize the turbines’ hub heights z. Third, we also provide a software implementation of the Gaussian wake model. The latter finds entrance to the open-source WFLO research framework that comes as package <strong>wflo</strong> for statistical software R. We find that taking wiring cost into account may lead to very different turbine placements, however, increasing overall profit significantly. Allowing the optimizer to vary the hub heights may have an ambiguous impact on the wind farm profit.

A*–Ant Colony Optimization Algorithm for Multi-Branch Wire Harness Layout Planning

The planning of multi-branch cable harness layouts holds significant practical importance in aircraft industrial contexts, yet it has received limited attention in prior research. This study aims to address the matter concerning the significance of managing multiple constraints and preventing loops. It formulates the problem as an optimization problem in 3D free-form space and resolves it using an extended A* path planning approach in combination with the ant colony optimization algorithm. Initially, a feasible search space for wiring is established through the repair and simplification of the input CAD model. Subsequently, the topology of a multi-branched wiring harness is identified, taking into account industrial requirements related to cable physics, turning, support, bundling, and electromagnetic compatibility constraints. Specifically, the disassembly or merging of branches and loops is employed to avoid wire loops. Ultimately, we propose an A*–ant colony optimization algorithm (A*-ACO) with an enhanced heuristic function for neighboring points, incorporating a concentration increment model. Experimental tests illustrate the effectiveness of this approach in minimizing wire loops and reducing the total cable layout cost, considering factors such as length, bundling, and turning costs. It results in a reduction of 67.0%, 68.5%, and 51.1% compared to A*, ACO, and manual wiring methods, respectively.

Aynı anma gerilimlerine sahip farklı iletkenlerden oluşan yüksek gerilim kabloları üzerine bir araştırma

Aluminum and copper conductors are commonly used in the transport of energy. In this work, high-voltage cables occurring aluminum and copper conductors exposed to the same rated voltage values were analyzed. In order to obtain the same current carrying capacity for copper and aluminum conductors, the relationship between the cross-sections has been determined and then the most appropriate cross-sectional values for each conductor were identified. Three different cross-sectional values have been selected for each conductor type and the calculations for the cables were carried out by using the Cable Ampacity Calculations Program (CYMCAP) within the framework of the International Electrotechnical Commission (IEC) standards. The performance of the cables has been compared in terms of material losses, cable structures and the cable costs. It is seen from the simulation results that aluminum conductor cables have lower cost and higher electrical loses than the copper conductor cables.

Comprehensive layout optimization of the transmission system in a deepwater wind farm cluster

Compared to nearshore wind farms, deepwater offshore wind farms have better wind resources and broader development space and will be the main trend of wind power development in the future. Due to the long distance from the shore, the investment and operation costs of the transmission system in a deepwater wind farm cluster are high and the electricity generated by the cluster is commonly transmitted by high-voltage direct current transmission technology to decrease power losses. For a given converter station, the comprehensive optimization of the layouts of the substations, AC export cables from the substation to the converter station, and cable arrays within each wind farm are complex and have not been well studied. This paper proposes a multi-level nested optimization strategy to minimize the total cost of the collection cables for a deepwater offshore wind farm cluster. The proposed method applies the Informed-RRT* method to optimize the layout of AC export cables while the cable arrays are arranged by Prim’s algorithm. During the optimization process, the gradient descent algorithm is used to optimize the positions of the substations, obtaining the transmission system scheme with the minimum cable investment. For a certain deepwater wind farm cluster, the total cable cost after optimization is reduced by 3.58%, which indicates the effectiveness of this method.

Comparative study of power production using a generic empirical model in a tidal farm

This study presents a generic model for estimating the velocity deficit and turbulence intensity ina tidal turbine farm. The proposed model considers a range of ambient turbulence intensity, the rotor diameter-to-depth ratio, and the rotor thrust coefficient in realistic applications. We evaluate the power generation of a large-scale tidal farm composed of 16 turbines in an in-line and staggered configuration in an ideal channel similar to the Alderney Race in the English Channel. The added turbulence effect is taken into account when assessing the velocity deficit in the farm. As supported by previous studies, the results show that the staggered array produces more power than the rectilinear array. The staggered arrangement benefits from flow acceleration and wide turbine spacing, which improves wake recovery. According to the results, the farm can be resized by decreasing the lateral spacing in the rectilinear array and decreasing the longitudinal spacing in the staggered array without affecting the farm’s efficiency. The reduction in farm size will reduce cable costs and provide an opportunity for future expansion. For the tidal turbines in shallow water regions, the ratio of rotor diameter to depth is shown to affect the power generated by the turbines. The power produced in the farm decreases with an increase in the rotor diameter-to-depth ratio due to the limited wake expansion along the vertical plane. This low-computational model can be useful in studying the wake interaction of tidal turbine parks in different configurations.

Selection of an optimal cable brand for high-voltage overhead power lines based on criterion analysis

This paper is aimed at developing a versatile approach to selecting an optimal cable brand for overhead transmission lines for use in design practice, adapted to conventional and new-generation cable types. To implement multi-criterion evaluation of external factors and limitations when selecting a cable type, the methods of systems, hierarchy and comparative analysis were used. A method for selecting an optimal cable brand based on hierarchy analysis was developed along with an algorithm for its implementation when designing new or modernizing existing overheadlines. The developed approach is demonstrated on the example of construction and modernization of 220 kV overhead lines with the conventional AC cable and such new-generation domestic brands, as АСВТ, АСВП, АСк2у and АСТ. In the considered examples, the technical feasibility of the construction of a new overhead line was limited by the value of the sag. For the modernization project, the specific weight of the cable was of greater importance. The selection criteria included the span length, cable cost and admissible continuous current. The АСВП and АСТ cable brands showed the greatest compliance with the selection criteria (27.5% and 55.9%, respectively). Therefore, at minimum capital investments, the АСВП brand ensures the optimum span length in the construction of a new overhead line, whereas the ACT brand ensures the maximum capacity in the modernization of an existing line. The conducted verification calculations confirmed the feasibility and versatility of the proposed method for selecting a cable brand.

FARKLI YÜKLEME ŞARTLARI İÇİN XLPE İZOLELİ DENİZALTI KABLOLARININ ISIL ANALİZİ

Submarine cables are critical assets that play an indispensable role in interconnected power systems, particularly in cross-sea energy transmission and offshore wind turbines. Their importance is further accentuated in exigent situations such as natural disasters and war, which emphasize the need for secure, reliable and uninterrupted energy supply. Furthermore, the investment and operating costs of submarine cables are relatively higher than other power system equipment, making it essential to operate them under the rated operating conditions to prevent possible faults and ensure power system stability. As thermal stress can lead to damage of cable insulation, it is an essential parameter to consider. Overloading increases thermal stress, resulting in rapid aging of the cable insulation and a shorter cable lifetime. Therefore, it is imperative to determine the maximum conductor temperatures and current carrying capacities of submarine cables under varying loading rates and ambient conditions using thermal analysis. In this study, thermal analyses are carried out for a three-phase, 220 kV HVAC, XLPE insulated submarine cable under different loading conditions. The findings demonstrate that the maximum temperature, current carrying capacity, and total losses of the cable are significantly impacted by loading rate, phase imbalance, and seawater temperature.

A bi‐level programming model and differential evolution for optimizing offshore wind farm layout

AbstractThe optimization of offshore wind farms is mainly performed through the deployment of wind farms and submarine cables to maximize power output and minimize cable costs. However, the above results are affected by the wake effect, equipment layout, and the cost of cables. To effectively complete the deployment of wind turbines and submarine cable lines, first, a bi‐level constrained optimization model based on maximum profit and the shortest route of cable is proposed in this paper; then, a differential evolution and improved Prim algorithm (IPADE) are used to optimize the upper‐ and lower‐level objective function, respectively. Moreover, the fitness values are used to divide the population, and a surrogate model is used to evaluate approximate fitness values for the sub‐population with poor performance; the best individual is selected as the offspring individual according to the approximate fitness values. Next, a clustering method is used to divide the position of the wind farm, and a Prim algorithm based on roulette wheel selection is designed to deploy submarine cables of every subwind farm. Finally, the proposed algorithm is compared with five other popular algorithms under the two wind conditions. The simulation experimental results show that algorithm IPADE performs better than other algorithms in terms of the power output, profit, and the length of cables.

Combined layout and cable optimization of offshore wind farms

Reducing wind energy costs is a crucial goal to promote renewable energy and reduce dependencies on fossil fuels, both to fight climate change and to increase energy independence. Two main optimization problems arise during the design of offshore wind farms: the Wind Farm Layout Optimization (WFLO) problem and the Wind Farm Cable Routing (WFCR) problem. The goal of WFLO is to find the optimal turbine locations within a given area to maximize revenues from energy production minus construction costs. The goal of WFCR is to minimize the costs of subsea cables that transfer the electricity produced by turbines. Traditionally, the two NP-hard problems have been studied separately and are solved sequentially, despite being strongly related. The output of WFLO defines the input to WFCR, and their goals are opposing: while larger distances between turbines have a positive effect on WFLO due to reduced wake losses, they negatively impact the cable costs in WFCR. Hence, we study the combined optimization problem, unifying the two problems. We propose a novel heuristic that uses a combined local search to modify solutions of WFLO and WFCR simultaneously. While the combined approach is more computationally demanding than the sequential approach, the proposed method solves industry-scale problems and improves up to 12 million Euro the Net Present Value (NPV) of wind parks, particularly when the energy density is low. Furthermore, the combined approach reduces the up-front investment costs by up to 10%, significantly reducing investment risks, and enabling a faster expansion of wind energy.

Assessment of energy production and costs associated with a massive exploitation of wind power in the North Sea

A study to assess the potential of a massive exploitation of offshore wind power in the North Sea has been performed. The study includes both a prediction of the available wind resources and the costs associated with such a large-scale exploitation of the wind power in the North Sea. The main parameters of the model are wind turbine size, average distance between the turbines (determined from area and number of turbines), as well as wind resources (i.e. mean wind speed Weibull distribution) and water depths conditioned on specific locations within the North Sea. The cost model includes expressions for the most essential wind farm cost elements, such as costs of wind turbines, support structures, cables and electrical substations, as well as costs of operation and maintenance - all as function of wind climate, rotor size, interspatial distance between the turbines and water depth. A main outcome of the study, is that exploiting an area of 180.000 km2, corresponding to about 1/3 of the North Sea, covered with 60.000 20 MW wind turbines, may in average produce electricity corresponding to the consumption of Europe at a price of 6.2 €cents/kWh (in 2020 prices). Furthermore, more energy could actually be captured by installing the wind turbines closer to each other. As an example, doubling the average power by installing more wind turbines on the same area will increase the levelized cost of energy from 6.2 €cent/kWh to 10.1 €cent/kWh. Still, this may be relevant in case of scarcity of suitable sites for a massive exploration.

Application of smart wayside object controllers to railway signalling systems for decarbonisation

In railway signalling systems, trackside equipment and signalling devices are controlled by wayside object controllers (OC). With the application of radio communication to wirelessly transmit command control and signals, the cost of cabling and installation has been significantly reduced. However, for non-electrified regional lines in rural areas, dedicated cables are still installed along the track to drive the wayside object controllers, which increases both capital and operational costs. With the development of renewable energy sources (RES) and wayside energy storage systems (ESS), a concept of smart wayside object controllers (SWOC) is proposed, which are autonomous, off-grid and powered by local renewable energy sources to reduce the related costs. To assist future system development, this work develops methods to not only calculate power and energy demand for system configuration but also estimate the life cycle cost in long-term operation. A case study based on a railway test site in Sweden is performed. This study shows that it is sufficient to use 100% local renewable energy sources to power the SWOC, trackside equipment and signalling devices. Compared with the existing system, the SWOC shows a significant cost saving in long-term operation by removing cabling and installation, reducing trackside maintenance and replacing the power supply with renewable energy power sources for decarbonisation. Therefore, the SWOC shows its significant benefits over the existing system from both economical and environmental aspects. In the end, some suggestions for future development and implementation of SWOC are given.

Ways to ensure the attenuation coefficient within the limits of normal values of single shielded twisted pair cables for industrial Ethernet networks

In recent years, the concept of Industry 4.0 and IioT has seen an intensive transition of industrial networks to wired data transmission based on the Ethernet family of technologies. The given chronology of the development of international standards of industrial Ethernet and corresponding cables based on twisted pairs proves the perspective of using a single twisted pair with the possibility of transmitting a power signal, which significantly reduces the number, weight and cost of cables in the network. According to international standards on cables for industrial Ethernet, shielded solutions based on a single shielded twisted pair must ensure the transmission of digital signals in the frequency range of up to 20 MHz over a distance of up to 1 kilometre. The need to use a shielded twisted pair is due to operating conditions under the influence of strong electromagnetic interference. An analytical review of scientific publications shows that shielded cable designs have increased values of electrical capacity. On the basis of numerical modelling of the electric field in the twisted pair, the value of the electrical capacity is determined depending on the design of the screen. It is shown that the shielded twisted pair has significantly larger (by 80 %), electrical capacity values compared to the unshielded one, provided the insulation, screen and protective polymer shell are of the same thickness. The effectiveness of the use of a two-layer aluminium polymer screen is substantiated. It has been proven that varying the thickness and dielectric permeability of the screen film material allows optimizing the cable design to ensure lower values of the working capacity compared to an unshielded pair. On the basis of numerical calculations, it is shown that when the two-layer screen is placed with the film outwards, the working capacity increases significantly and does not differ from the capacity shielded with a solid metal screen. The validity and adequacy of the performed numerical calculations of the electrical capacity of twisted pairs is confirmed by experimental results of measurements of the attenuation coefficient in the frequency range up to 20 MHz of unshielded and shielded twisted pair with a two-layer laminated screen.

Techno-economic assessment of hydrogen production from seawater

Population growth and the expansion of industries have increased energy demand and the use of fossil fuels as an energy source, resulting in release of greenhouse gases (GHG) and increased air pollution. Countries are therefore looking for alternatives to fossil fuels for energy generation. Using hydrogen as an energy carrier is one of the most promising alternatives to replace fossil fuels in electricity generation. It is therefore essential to know how hydrogen is produced. Hydrogen can be produced by splitting the water molecules in an electrolyser, using the abondand water resources, which are covering around ⅔ of the Earth's surface. Electrolysers, however, require high-quality water, with conductivity in the range of 0.1–1 μS/cm. In January 2018, there were 184 offshore oil and gas rigs in the North Sea which may be excellent sites for hydrogen production from seawater. The hydrogen production process reported in this paper is based on a proton exchange membrane (PEM) electrolyser with an input flow rate of 300 L/h. A financially optimal system for producing demineralized water from seawater, with conductivity in the range of 0.1–1 μS/cm as the input for electrolyser, by WAVE (Water Application Value Engine) design software was studied. The costs of producing hydrogen using the optimised system was calculated to be US$3.51/kg H2. The best option for low-cost power generation, using renewable resources such as photovoltaic (PV) devices, wind turbines, as well as electricity from the grid was assessed, considering the location of the case considered. All calculations were based on assumption of existing cable from the grid to the offshore, meaning that the cost of cables and distribution infrastructure were not considered. Models were created using HOMER Pro (Hybrid Optimisation of Multiple Energy Resources) software to optimise the microgrids and the distributed energy resources, under the assumption of a nominal discount rate, inflation rate, project lifetime, and CO2 tax in Norway. Eight different scenarios were examined using HOMER Pro, and the main findings being as follows:The cost of producing water with quality required by the electrolyser is low, compared with the cost of electricity for operation of the electrolyser, and therefore has little effect on the total cost of hydrogen production (less than 1%).The optimal solution was shown to be electricity from the grid, which has the lowest levelised cost of energy (LCOE) of the options considered. The hydrogen production cost using electricity from the grid was about US$ 5/kg H2.Grid based electricity resulted in the lowest hydrogen production cost, even when costs for CO2 emissions in Norway, that will start to apply in 2025 was considered, being approximately US$7.7/kg H2.From economical point of view, wind energy was found to be a more economical than solar.