Flexible production of green hydrogen and ammonia from variable solar and wind energy: Case study of Chile and Argentina

We report a techno-economic modelling for the flexible production of hydrogen and ammonia from water and optimally combined solar and wind energy. We use hourly data in four locations with world-class solar in the Atacama desert and wind in Patagonia steppes. We find that hybridization of wind and solar can reduce hydrogen production costs by a few percents, when the effect of increasing the load factor on the electrolyser overweighs the electricity cost increase. For ammonia production, the gains by hybridization can be substantially larger, because it reduces the power variability, which is costly, due to the need for intermediate storage of hydrogen between the flexible electrolyser and the less flexible ammonia synthesis unit. Our modelling reveals the crucial role in the synthesis of flexibility, which cuts the cost of variability, especially for the more variable wind power. Our estimated near-term production costs for green hydrogen, around 2 USD/kg, and green ammonia, below 500 USD/t, are encouragingly close to competitiveness against fossil-fuel alternatives.     

Large scale hydrogen production utilizing carbon in renewable resources

By the year 2000 the hydrogen requirements could be met using about one third of available residues. The large and increasing amounts of wastes and residues from agriculture, forestry, other industrial and municipal activities are viewed as renewable resources to provide large amounts of hydrogen. In carbon content the current magnitude of such residues exceeds that in the current annual production of all of the coal mined in the U.S. The hydrogen would be produced from these residues by pyrolysis-gasification processes followed by completing the reaction between water and carbon monoxide. The resulting mixture obtainable from oxygen-blown gasifiers is principally hydrogen together with carbon dioxide and water vapor which are readily separated to yield nearly pure hydrogen. A net yield of one pound of hydrogen per five pounds of carbon in the residue is anticipated. Environmental concerns and intensified and expanding agriculture with the development of more effective residue collection and delivery systems assure that residues will be more economical than the conventional carbon resources which are to increase in cost and decline in availability. The demand for hydrogen has been projected to the years 2000 and 2020 at 14 and 50 quads respectively.     

Statistical analysis of wind energy in Chile

Bearing in mind the current and pressing need for an update of the existing Chilean power supply system – which has been remarkably influenced by new requirements – the search for new energy supply sources has become a top priority.The wind resource, vis-à-vis its associated mature technology features and its apparent availability throughout Chile, comes forward as a feasible option likely to play a more important role in any future national energy generation matrix.With a view to understanding the local wind resource, this document surveys a sample set of wind profiles available in the northern Chile area, thus becoming the first public survey of this kind. It also tackles theoretical energy production and capacity factors. Those became the basis of the wind modelling we undertook for Chile’s participation in COP15. This paper shows wind generation is a suitable option for curbing down Greenhouse Gas Emissions (GHG) in Chile.     

Evaluation of hydrogen production by wind energy for agricultural and industrial sectors

Wind power potential by itself is not a good indicator of the suitability of a region for wind power generation for different purposes. Economic attractiveness is a better indicator in this regard as it stimulates the involvement of private businesses in this sector. Naturally, the shorter is the payback period or the time required to reach profitability, the more attractive will be the project. Considering the high wind energy potential of some regions of Iran, this study evaluates the wind energy available for generating electricity as well as hydrogen by industrial and agricultural sectors in four cities of Ardebil province, namely Ardebil, Khalkhal, Namin, and Meshkinshahr, and then conducts an econometric analysis accordingly. Wind power potentials are evaluated using the energy pattern factor and Weibull distribution function based on 5-year meteorological data of the studied regions. Economic evaluations are performed based on the present worth of incomes and costs, which are estimated for two models of wind turbines with 3.5 and 100 KW rated power. Results indicate that the cities of Namin and Ardebil with wind power densities of respectively 261.68 and 258.99 W/m² have the best condition. The economic analysis conducted for turbines shows that for Ardebil, installation of the 3.5 KW and 100 KW turbines will have a payback period of 13 and 5 years, respectively. For Khalkhal, Namin, and Meshkinshahr, the only feasible option is installation of the 100 KW turbine, which would result in a payback period of respectively 10.2, 6.1 and 8.7 years. Then it is investigated how much hydrogen can be gained if these private sectors invest in producing hydrogen using nominated wind turbines.     

Techno-economic assessment of green hydrogen and ammonia production from wind and solar energy in Iran

This paper presents a comprehensive technical and economic assessment of potential green hydrogen and ammonia production plants in different locations in Iran with strong wind and solar resources. The study was organized in five steps. First, regarding the wind density and solar PV potential data, three locations in Iran were chosen with the highest wind power, solar radiation, and a combination of both wind/solar energy. All these locations are inland spots, but since the produced ammonia is planned to be exported, it must be transported to the export harbor in the South of Iran. For comparison, a base case was also considered next to the export harbor with normal solar and wind potential, but no distance from the export harbor. In the second step, a similar large-scale hydrogen production facility with proton exchange membrane electrolyzers was modeled for all these locations using the HOMER Pro simulation platform. In the next step, the produced hydrogen and the nitrogen obtained from an air separation unit are supplied to a Haber-Bosch process to synthesize ammonia as a hydrogen carrier. Since water electrolysis requires a considerable amount of water with specific quality and because Iran suffers from water scarcity, this paper, unlike many similar research studies, addresses the challenges associated with the water supply system in the hydrogen production process. In this regard, in the fourth step of this study, it is assumed that seawater from the nearest sea is treated in a desalination plant and sent to the site locations. Finally, since this study intends to evaluate the possibility of green hydrogen export from Iran, a detailed piping model for the transportation of water, hydrogen, and ammonia from/to the production site and the export harbor is created in the last step, which considers the real routs using satellite images, and takes into account all pump/compression stations required to transport these media. This study provides a realistic cost of green hydrogen/ammonia production in Iran, which is ready to be exported, considering all related processes involved in the hydrogen supply chain.     

A regional decision support system for onsite renewable hydrogen production from solar and wind energy sources

Hydrogen technologies driven by renewable energy sources (RES) represent an attractive energy solution to ensure environmental sustainability. In this paper, a decision support system for the hydrogen exploitation is presented, focusing on some specific planning aspects. In particular, the planning aspects regard the selection of locations with high hydrogen production mainly based on the use of solar and wind energy sources. Four modules were considered namely, the evaluation of the wind and solar potentials, the analysis of the hydrogen potential, the development of a regional decision support module and a last module that regards the modelling of a hybrid onsite hydrogen production system. The overall approach was applied to a specific case study in Liguria region, in the north of Italy.     

Analysis of hydrogen production from combined photovoltaics, wind energy and secondary hydroelectricity supply in Brazil

In this work, the technical and economical feasibility for implementing a hypothetical electrolytic hydrogen production plant, powered by electrical energy generated by alternative renewable power sources, wind and solar, and conventional hydroelectricity, was studied mainly trough the analysis of the wind and solar energy potentials for the northeast of Brazil. The hydrogen produced would be exported to countries which do not presently have significant renewable energy sources, but are willing to introduce those sources in their energy system. Hydrogen production was evaluated to be around 56.26 × 10⁶ m³ H₂/yr at a cost of 10.3 US$/kg.     

Evaluation of a wind energy based system for co-generation of hydrogen and methanol production

A novel idea of wind energy based methanol and hydrogen production is proposed in this study. The proposed system utilizes the industrial carbon emissions to produce a useful output of methanol. There are several pros of manufacturing the methanol as it has the capability to be employed as conventional automotive fuel as it carries the advantages of efficient performance, low emissions and low flammability risk. The designed system comprises of the major subsystems of wind turbines, proton exchange membrane fuel cell (PEMFC), methanol production system and distillation unit. The Engineering Equation Solver (EES) and Aspen Plus are utilized for system modeling and comprehensive analysis. The proposed system is also investigated to operate under different wind speeds and different wind turbine efficiencies. The proposed integration covers all the electric power required by the system. The industrial flue gas including CO₂ reacts with hydrogen to produce methanol. The designed system produces both methanol and hydrogen simultaneously. For the performance indicator, efficiencies of the overall system are calculated. The exergetic efficiency is found to be 38.2% while energetic efficiency is determined to be 39.8%. Furthermore, some parametric studies are conducted to investigate the distillation column performance, methanol and hydrogen capacities and exergy destruction rates.     

Heat transfer problems for the production of hydrogen from geothermal energy

Electrolysis at low temperature is currently used to produce Hydrogen. From a thermodynamic point of view, it is possible to improve the performance of electrolysis while functioning at high temperature (high temperature electrolysis: HTE). That makes it possible to reduce energy consumption but requires a part of the energy necessary for the dissociation of water to be in the form of thermal energy.

A collaboration between France and Iceland aims at studying and then validating the possibilities of producing hydrogen with HTE coupled with a geothermal source. The influence of the exit temperature on the cost of energy consumption of the drilling well is detailed.

To vaporize the water to the electrolyser, it should be possible to use the same technology currently used in the Icelandic geothermal context for producing electricity by using a steam turbine cycle. For heating the steam up to the temperature needed at the entrance of the electrolyser three kinds of heat exchangers could be used, according to specific temperature intervals.     

Operational challenges for low and high temperature electrolyzers exploiting curtailed wind energy for hydrogen production

Understanding the system performance of different electrolyzers could aid potential investors achieve maximum return on their investment. To realize this, system response characteristics to 4 different summarized data sets of curtailed renewable energy is obtained from the Irish network and was investigated using models of both a Low Temperature Electrolyzer (LTE) and a High Temperature Electrolyzer (HTE). The results indicate that statistical parameters intrinsic to the method of data extraction along with the thermal response time of the electrolyzers influence the hydrogen output. A maximum hydrogen production of 5.97 kTonne/year is generated by a 0.5 MW HTE when the electrical current is sent as a yearly average. Additionally, the high thermal response time in a HTE causes a maximum change in the overall flowrate of 65.7% between the 4 scenarios, when compared to 7.7% in the LTE. This evaluation of electrolyzer performance will aid investors in determining scenario specific application of P2G for maximizing hydrogen production.     

PEM electrolysis for production of hydrogen from renewable energy sources

PEM electrolysis is a viable alternative for generation of hydrogen from renewable energy sources. Several possible applications are discussed, including grid independent and grid assisted hydrogen generation, use of an electrolyzer for peak shaving, and integrated systems both grid connected and grid independent where electrolytically generated hydrogen is stored and then via fuel cell converted back to electricity when needed. Specific issues regarding the use of PEM electrolyzer in the renewable energy systems are addressed, such as sizing of electrolyzer, intermittent operation, output pressure, oxygen generation, water consumption and efficiency.     

Assessment of offshore liquid hydrogen production from wind power for ship refueling

Green hydrogen from electrolysis has become the most attractive energy carrier for making the transition from fossil fuels to carbon-free energy sources possible. Especially in the naval sector, hydrogen has the potential to address environmental targets due to the lack of low-carbon fuel options. This study aims at investigating an offshore liquefied green hydrogen production plant for ship refueling. The plant comprises a wind farm for renewable electricity generation, an electrolyzer stack for hydrogen production, a water treatment unit for demineralized water production, and a hydrogen liquefaction plant for hydrogen storage and distribution to ships. A pre-feasibility study is addressed to find the optimal capacities of the plant that minimize the payback time. The model results show that the electrolyzer capacity shall be set equal to a value between 80% and 90% of the wind farm capacity to achieve the minimum payback times. Additionally, the wind farm capacity shall be higher than about 150 MW to limit the payback time to values lower than 11 years for a fixed hydrogen price of 6 €/kg. The Levelized Cost of Hydrogen results to be below 4 €/kg for a wide range of plant capacities for a lifetime of the plant of 25 years. Thus, the model shows that this plant is economically feasible and can be reproduced similarly for different locations by rescaling the different selected technologies. In this way, the naval sector can be decarbonized thanks to a new infrastructure for the production and refueling of liquified green hydrogen directly provided on the sea.     

Evaluation of hydrogen production from harvesting wind energy at high altitudes in Iran by three extrapolating Weibull methods

One of the most appropriate ways for energy storage is producing hydrogen from renewable resources. Wind energy is recognized as one of the widely used renewable energy resources. This paper investigates the use of wind energy for producing hydrogen in Iran. To achieve this, the country is divided into five major regions: center, north, south, east and west. The performance of three large-scale commercial wind turbines, ranging from 1500 kW to 3000 kW at hub height of 80 m and four large-scale wind turbine ranging from 2000 kW to 4500 kW at hub height of 120 m are evaluated for producing hydrogen in 150 wind stations in Iran. All wind data were recorded based on 10-min time intervals for more than one year at different wind mast heights. For estimating Weibull parameters, the Standard Deviation Method (SDM), Empirical Method of Lysen (EML) and Power Density Method (PDM) are used. An extrapolation method is used to determine the shape and the scale parameters of the Weibull distribution at the high attitudes of 80 m and 120 m. Then, power law and surface roughness exponents, capacity factor, annual energy production and annual hydrogen production for the wind sites are determined. The results indicate that rated power is not the only determinative parameter and the highest hydrogen production is from the GW-109/2500 wind turbine at the hub height of 80 m and from E112/4500 at the hub height of 120 m. For better assessment, the amount of hydrogen production is depicted in Geographic Information Science (GIS) maps using power production of the seven wind turbine models. Next by analyzing these GIS maps, it is found that there are significant potentials in north, north-west, east and south of Iran for producing hydrogen from wind energy.     

A geospatial method for estimating the levelised cost of hydrogen production from offshore wind

This paper describes the development of a general-purpose geospatial model for assessing the economic viability of hydrogen production from offshore wind power. A key feature of the model is that it uses the offshore project's location characteristics (distance to port, water depth, distance to gas grid injection point). Learning rates are used to predict the cost of the wind farm's components and electrolyser stack replacement. The notional wind farm used in the paper has a capacity of 510 MW. The model is implemented in a geographic information system which is used to create maps of levelised cost of hydrogen from offshore wind in Irish waters. LCOH values in 2030 spatially vary by over 50% depending on location. The geographically distributed LCOH results are summarised in a multivariate production function which is a simple and rapid tool for generating preliminary LCOH estimates based on simple site input variables.     

Optimization of self-regulated hydrogen production from photovoltaic energy

The use of photovoltaic energy (PV) for the production of hydrogen by using autonomous modular self-regulated systems is studied. Results are compared with those obtained for controlled systems. It was proved that for small and low-cost applications, it is possible to eliminate any control system with yields as high as 91.2% in the PV-electrolyzer interface for a sunny day. Self-regulated systems are thus an excellent, safe, cheap and environmentally friendly alternative for applications in isolated sites, especially in emerging countries.     

Feasibility study of hydrogen production from wind power in the region of Ghardaia

A feasibility study on hydrogen production from wind power on the site of Ghardaia is carried out. This study is based on the estimation of the hydrogen rate produced by a 5 kW electrolyser fed by the electricity provided by a 10 kW wind turbine.Wind speed data were used to study the monthly variation of the wind power delivered and its variation according to the height of the wind turbine tower.The obtained results show that it is possible to improve the system output by increasing the height of the wind turbine tower. Indeed, it has been obtained 3200 Nm³ of hydrogen production for a 30 m wind turbine height and 4200 Nm³ at 60 m.In addition, it has been noticed that hydrogen production varies strongly with the months of the year. Thus, the production has reached a maximum of 395 Nm³ in May and a minimum of 187 Nm³ during November and October.     

Hydrogen production from wind energy in Western Canada for upgrading bitumen from oil sands

Hydrogen is produced via steam methane reforming (SMR) for bitumen upgrading which results in significant greenhouse gas (GHG) emissions. Wind energy based hydrogen can reduce the GHG footprint of the bitumen upgrading industry. This paper is aimed at developing a detailed data-intensive techno-economic model for assessment of hydrogen production from wind energy via the electrolysis of water. The proposed wind/hydrogen plant is based on an expansion of an existing wind farm with unit wind turbine size of 1.8 MW and with a dual functionality of hydrogen production and electricity generation. An electrolyser size of 240 kW (50 Nm³ H₂/h) and 360 kW (90 Nm³ H₂/h) proved to be the optimal sizes for constant and variable flow rate electrolysers, respectively. The electrolyser sizes aforementioned yielded a minimum hydrogen production price at base case conditions of $10.15/kg H₂ and $7.55/kg H₂. The inclusion of a Feed-in-Tariff (FIT) of $0.13/kWh renders the production price of hydrogen equal to SMR i.e. $0.96/kg H_2, with an internal rate of return (IRR) of 24%. The minimum hydrogen delivery cost was $4.96/kg H₂ at base case conditions. The life cycle CO₂ emissions is 6.35 kg CO₂/kg H₂ including hydrogen delivery to the upgrader via compressed gas trucks.     

Offshore wind power simulation by using WRF in the central coast of Chile

This paper presents the first estimate of offshore wind power potential for the central coast of Chile. For this purpose, wind speed data from in-situ stations and ERA-Interim reanalysis were used to simulate wind fields at regional level by means of the Weather Research and Forecasting (WRF) model. Wind field simulations were performed at different heights (20, 30, 40 and 140 m.a.s.l.) and a spatial resolution of 3 × 3 km for the period from February 1, 2006 to January 31, 2007, which comprised the entire series of in-situ data available. The results show an RMSE and r² of 2.2 m s⁻¹ and 0.55 respectively for the three heights simulated as compared to in-situ data. Based on the simulated wind data, the wind power for the study area was estimated at ∼1000 W m⁻² at a height of 140 m.a.s.l. For a typical wind turbine of 8 MW generator, the estimated capacity factor exceeds 40%, with an average annual generation of ∼30 GWh. Offshore wind power in Chile is an emerging renewable energy source that is as yet still under-developed, these estimates help to fill in some of the gaps in our knowledge about Chile's true renewable energy potential.     

Improving wind speed forecasts from the Weather Research and Forecasting model at a wind farm in the semiarid Coquimbo region in central Chile

Accurate predictions of the wind field are key for better wind power forecasts. Wind speed forecasts from numerical weather models present differences with observations, especially in places with complex topography, such as the north of Chile. The present study has two goals: (a) to find the WRF model boundary layer (PBL) scheme that best reproduces the observations at the Totoral Wind Farm, located in the semiarid Coquimbo region in north‐central Chile, and (b) to use an artificial neural network (ANN) to postprocess wind speed forecasts from different model domains to analyze the sensitivity to horizontal resolution. The WRF model was run with three different PBL schemes (MYNN, MYNN3, and QNSE) for 2013. The WRF simulation with the QNSE scheme showed the best agreement with observations at the wind farm, and its outputs were postprocessed using two ANNs with two algorithms: backpropagation (BP) and particle swarm optimization (PSO). These two ANNs were applied to the innermost WRF domains with 3‐km (d03) and 1‐km (d04) horizontal resolutions. The root‐mean‐square errors (RMSEs) between raw WRF forecasts and observations for d03 and d04 were 2.7 and 2.4 ms^?1 , respectively. When both ANN models (BP and PSO) were applied to Domains d03 and d04, the RMSE decreased to values lower than 1.7 ms^?1 , and they showed similar performances, supporting the use of an ANN to postprocess a three‐nested WRF domain configuration to provide more accurate forecasts in advance for the region.