Estimating global hydrogen production from wind

It is likely that intermittent renewable sources such as wind and solar will provide the greatest opportunity for future large-scale hydrogen production. Here, on-shore wind is examined. Global wind energy is estimated by placing one 2 MW turbine/km² over the surface of the earth. Wind energy production is based on monthly mean wind speed data. Wind turbines are grouped to form arrays that are linked to local hydrogen generation and transmission networks. Hydrogen generation is done via low-pressure electrolysis and transmission via high-pressure gas pipelines. The wind/hydrogen system is considered within a global energy system that must not only provide hydrogen, but also energy for electricity consumption at the local generation site. The technical potential of the hydrogen produced is estimated to be 116 EJ. Uneven distribution of the hydrogen-rich sites results in the need to export much of the hydrogen produced to energy-poor regions. To overcome system losses, a combined wind/HVDC/hydrogen system is considered.     

Wind energy development policy and prospects in Lithuania

According to the EU Directive 2001/77/EC 7% of all electricity production is to be generated from renewable energy sources (RES) in Lithuania in 2010. Electricity production from RES is determined by hydro, biomass and wind energy resources in Lithuania. Further development of hydro power plants is limited by environmental restrictions, therefore priority is given to wind energy development. The aim of this paper is to show estimation of the maximum wind power penetration in the Lithuanian electricity system using such criteria as wind potential, possibilities of the existing electricity network, possible environmental impact, and social and economical aspects. Generalization of data from the meteorological stations and special measurements shows that the highest average wind speed in Lithuanian territory is in the coastal region and at 50 m above ground level reaches 6.4 m/s. In regard to wind resource distribution in this region, arrangement of electricity grid and environment protection requirements, six zones have been determined for wind power plant construction. Calculations have shown that the largest total installed capacity of wind farms, which could cause no significant increase in power transmission expenses, is 170 MW. The threshold, which cannot be passed without capital reconstruction of electricity network, is 500 MW of total capacity of wind farms.     

An analysis of hydrogen production from renewable electricity sources

Three aspects of producing hydrogen via renewable electricity sources are analyzed to determine the potential for solar and wind hydrogen production pathways: a renewable hydrogen resource assessment, a cost analysis of hydrogen production via electrolysis, and the annual energy requirements of producing hydrogen for refueling. The results indicate that ample resources exist to produce transportation fuel from wind and solar power. However, hydrogen prices are highly dependent on electricity prices. For renewables to produce hydrogen at $2 kg⁻¹, using electrolyzers available in 2004, electricity prices would have to be less than $0.01 kWh⁻¹. Additionally, energy requirements for hydrogen refueling stations are in excess of 20 GWh/year. It may be challenging for dedicated renewable systems at the filling station to meet such requirements. Therefore, while plentiful resources exist to provide clean electricity for the production of hydrogen for transportation fuel, challenges remain to identify optimum economic and technical configurations to provide renewable energy to distributed hydrogen refueling stations.     

Germany’s wind energy: The potential for fossil capacity replacement and cost saving

Wind energy has become the major renewable energy source in Germany with an installed capacity of more than 20 GW and an annual output of about 40 TW h in 2007. In this paper we analyze the extent to which wind energy can replace fossil capacities based on wind injection and demand data for 2006 through June 2008. The results indicate that the wind potential in Germany will not allow a significant reduction of fossil capacities. We also assess the potential savings due to wind energy. The German market is modeled with and without wind input to estimate the net savings of fossil fuels in the observation period. We find that the cost-saving potential for electricity production is quite significant and exceeds the subsidies.     

Renewable energy sources in the Egyptian electricity market: A review

This review paper presents an appraisal of renewable energy RE options in Egypt. An appraisal review of different REs is presented. The study shows that electric energy produced from REs in Egypt are very poor compared with other energy sources. The utilization of the renewable energies can also be a good opportunity to fight the desertification and dryness in Egypt which is about 60% of Egypt territory. The rapid growth of energy production and consumption is strongly affecting and being affected by the Egyptian economy in many aspects. It is evident that energy will continue to play an important role in the development of Egypt's economy in coming years. The total installed electricity generating capacity had reached around 22025 MW with a generating capacity reached 22605 MW at the end of 2007. Hydropower and coal has no significant potential increase. During the period 1981/82-2004/05 electricity generation has increased by 500% from nearly 22 TWh for the year 1981/1982 to 108.4 TWh in the year 2004/2005 at an average annual growth rate of 6.9%. Consequently, oil and gas consumed by the electricity sector has jumped during the same period from around 3.7 MTOE to nearly 21 MTOE. The planned installed capacity for the year 2011/2012 is 28813 MW and the required fuel (oil and gas) for the electricity sector is estimated to reach about 29 MTOE by the same year. The renewable energy strategy targets to supply 3% of the electricity production from renewable resources by the year 2010. Electrical Coverage Electrical energy has been provided for around 99.3% of Egypt's population, representing a positive sign for the welfare of the Egyptian citizen due to electricity relation to all development components in all walks of life. The article discusses perspectives of wind energy in Egypt with projections to generate ∼ 3.5 GWe by 2022, representing ∼9% of the total installed power at that time (40.2 GW). Total renewables (hydro + wind + solar) are expected to provide ∼7.4 GWe by 2022 representing ∼ 19% of the total installed power. Such a share would reduce dependence on depleting oil and gas resources, and hence improve country's sustainable development.     

Wind energy (30%) in the Spanish power mix—technically feasible and economically reasonable

The installed wind power capacity in Spain has grown strongly in recent years. In 2007, wind parks supplied already 10% of the 260 TWh generated electricity. Along that year the installed wind capacity grew by 33.2%, from 11.63 GW in January to 15.5 GW in December. Wind is nowadays the primer renewable power source in Spain, while the public perception of renewables in general is very positive. The issue of the integration of wind power as a fluctuating source into the power grid is gaining priority.     

Resource assessment for green hydrogen production in Kazakhstan

Kazakhstan has long been regarded as a major exporter of fossil fuel energy. As the global energy sector is undergoing an unprecedented transition to low-carbon solutions, new emerging energy technologies, such as hydrogen production, require more different resource bases than present energy technologies. Kazakhstan needs to consider whether it has enough resources to stay competitive in energy markets undergoing an energy transition. Green hydrogen can be made from water electrolysis powered by low-carbon electricity sources such as wind turbines and solar panels. We provided the first resource assessment for green hydrogen production in Kazakhstan by focusing on three essential resources: water, renewable electricity, and critical raw materials. Our estimations showed that with the current plan of Kazakhstan to keep its water budget constant in the future, producing 2–10 Mt green hydrogen would require reducing the water use of industry in Kazakhstan by 0.6–3% or 0.036–0.18 km³/year. This could be implemented by increasing the share of renewables in electricity generation and phasing out some of the water- and carbon-intensive industries. Renewable electricity potential in South and West Kazakhstan is sufficient to run electrolyzers up to 5700 and 1600 h/year for wind turbines and solar panels, respectively. In our base case scenario, 5 Mt green hydrogen production would require 50 GW solar and 67 GW wind capacity, considering Kazakhstan's wind and solar capacity factors. This could convert into 28,652 tons of nickel, 15,832 tons of titanium, and many other critical raw materials. Although our estimations for critical raw materials were based on limited geological data, Kazakhstan has access to the most critical raw materials to support original equipment manufacturers of low-carbon technologies in Kazakhstan and other countries. As new geologic exploration kicks off in Kazakhstan, it is expected that more deposits of critical raw materials will be discovered to respond to their potential future needs for green hydrogen production.     

A 100% renewable electricity generation system for New Zealand utilising hydro,wind, geothermal and biomass resources

The New Zealand electricity generation system is dominated by hydro generation at approximately 60% of installed capacity between 2005 and 2007, augmented with approximately 32% fossil-fuelled generation, plus minor contributions from geothermal, wind and biomass resources. In order to explore the potential for a 100% renewable electricity generation system with substantially increased levels of wind penetration, fossil-fuelled electricity production was removed from an historic 3-year data set, and replaced by modelled electricity production from wind, geothermal and additional peaking options. Generation mixes comprising 53–60% hydro, 22–25% wind, 12–14% geothermal, 1% biomass and 0–12% additional peaking generation were found to be feasible on an energy and power basis, whilst maintaining net hydro storage. Wind capacity credits ranged from 47% to 105% depending upon the incorporation of demand management, and the manner of operation of the hydro system. Wind spillage was minimised, however, a degree of residual spillage was considered to be an inevitable part of incorporating non-dispatchable generation into a stand-alone grid system. Load shifting was shown to have considerable advantages over installation of new peaking plant. Application of the approach applied in this research to countries with different energy resource mixes is discussed, and options for further research are outlined.     

Offshore wind development in China and its future with the existing renewable policy

Based on independent studies, this paper focuses on the significant discrepancy of 15 GW between the installed onshore wind generation capacity and what has been actually connected to the power network to reveal the challenges in meeting the Chinese renewable energy target. The recent accidents in Chinese North-Western transmission network (in February–April, 2011) demonstrated the urgent need for a fundamental review of the Chinese renewable energy policy. Offshore wind has been identified as the most feasible alternative to onshore wind to help deliver electricity to Eastern China during the summer peak time. By investigating and summarizing first hand experiences of participation in the Chinese renewable market, the authors provide the economic figures of the first cohort of Chinese offshore wind schemes. Large state owned enterprises (SOE) are dominating the offshore wind development, repeating their previous practices on the land. While this paper acknowledges the critical role of offshore wind generation in meeting Chinese renewable energy targets, it envisages an installed offshore capacity of approximately 2000 MW by 2015, much less than the 10000 MW governmental estimation, which can be attributed to the lack of detailed energy policy, network constraints, offshore wind installation difficulties and quality issues in the manufacture of turbines.     

Optimal asset allocation of wind energy units in conjunction with demand response for a large‐scale electric grid

Demand response is considered to be a realistic and comparatively inexpensive solution aimed at increasing the penetration of renewable generations into the bulk electricity systems. The work in this paper highlights the demand response in conjunction with the optimal capacity of installed wind energy resources allocation. Authors proposed a total annual system cost model to minimize the cost of allocating wind power generating assets. This model contains capacity expansion, production, uncertainty, wind variability, emissions, and elasticity in demand to find out cost per hour to deliver electricity. A large‐scale electric grid (25 GW) is used to apply this model. Authors discovered that demand response based on interhourly system is not as much helpful as demand response grounded on intrahourly system. According to results, 32% wind generation share will provide the least cost. It is also worth noting that optimal amount of wind generation is much sensitive to installation cost as well as carbon tax.     

Spatial variation of emissions impacts due to renewable energy siting decisions in the Western U.S. under high-renewable penetration scenarios

One of the policy goals motivating programs to increase renewable energy investment is that renewable electric generation will help reduce emissions of CO₂ as well as emissions of conventional pollutants (e.g., SO₂ and NO_x). As a policy instrument, Renewable Portfolio Standards (RPS) encourage investments in wind, solar and other generation sources with the goal of reducing air emissions from electricity production. Increased electricity production from wind turbines is expected to displace electricity production from fossil-fired plants, thus reducing overall system emissions. We analyze the emissions impacts of incremental investments in utility-scale wind power, on the order of 1 GW beyond RPS goals, in the Western United States using a utility-scale generation dispatch model that incorporates the impacts of transmission constraints. We find that wind investment in some locations leads to slight increases in overall emissions of CO₂, SO₂ and NO_x. The location of wind farms influences the environmental impact by changing the utilization of transmission assets, which affects the overall utilization of power generation sources and thus system-level emissions. Our results suggest that renewable energy policy beyond RPS targets should be carefully crafted to ensure consistency with environmental goals.     

A framework for reviewing the trade-offs between, renewable energy, food, feed and wood production at a local level

High fuel prices and concerns about energy security and anthropogenic climate change are encouraging a transition towards a low carbon economy. Although energy policy is typically set at a national level, tools are needed for people to engage with energy policy at regional and local levels, and to guide decisions regarding land use, distributed generation and energy supply and demand. The aim of this paper is to develop a per-capita approach to renewable energy demand and supply within a landscape and to illustrate the key trade-offs between renewable energy, food, (animal) feed and wood production. The chosen case study area (16,000 ha) of Marston Vale, England is anticipated to have a population density midway between that for England and the UK. The daily per capita demand for energy for heat (31 kWh), transport (34 kWh) and electricity (15 kWh) when combined (80 kWh) was seven-fold higher than the combined demand for food (2 kWh), animal feed (6 kWh), and wood (4 kWh). Using described algorithms, the combined potential energy supply from domestic wind and photovoltaic panels, solar heating, ground-source heat, and municipal waste was limited (<10 kWh p⁻¹ d⁻¹). Additional electricity could be generated from landfill gas and commercial wind turbines, but these have temporal implications. Using a geographical information system and the Yield-SAFE tree and crop yield model, the capacity to supply bioethanol, biodiesel, and biomass, food, feed and wood was calculated and illustrated for three land-use scenarios. These scenarios highlight the limits on meeting energy demands for transport (33%) and heat (53%), even if all of the arable and grassland area was planted to a high yielding crop like wheat. The described framework therefore highlights the major constraints faced in meeting current UK energy demands from land-based renewable energy and the stark choices faced by decision makers.     

Performance investigation of hydrogen production from a hybrid wind-PV system

In this study, a hybrid system consisted of 10 kW wind and 1 kWp PV array is built to meet the load demand of a raise chucker partridge raising facility by renewable energy sources. The facility has an average energy consumption of about 20.33 kWh/day, with a peak demand of 2.4 kW. The solar radiation data and wind data of the region are analyzed for sizing of the renewable energy system. The performance of each alternative system is examined in terms of energy efficiency, and H₂ production capacity of the hybrid system from due to excessive electrical energy is studied. A Matlab-Simulink Software is used for analyzing the system performance. The average range of state of charge varies between 56.6% and 88.3% monthly from April to July. The amount of hydrogen production by excess electricity is 14.4 kg in the month of July, due to the high wind speed and solar radiation. Energy efficiency of the electrolyser is found to be varying between 64% and 70% percent. Energy efficiency of each hybrid system is calculated. The overall energy efficiency of wind-electrolyser system varies between 5% and 14% while the energy efficiency of PV-electrolyser system changes within a narrower range, as between 7.9% to and 8.5%, respectively.     

Impact of a large penetration of wind generation on the GB gas network

Wind power is expected to be the major element of renewable electricity generation in Great Britain (GB) by 2020 with a capacity of around 30 GW. The potential impact of a large amount of wind generation on the GB gas network was investigated using a combined gas and electricity network model. The varying nature of gas and electric power flows, network support facilities such as gas storage and compressors, and the power ramping characteristics of various power plants were considered. Three case studies were modelled, one case uses the existing network and the other two make use of a hypothesised network in 2020 with two distinct levels of wind generation representing low and high wind periods. The simulation results show that a large penetration of wind generation will influence the electricity generation mix as the wind power varies. Gas-fired generation is used to compensate for wind variability. This will cause increased flows and compressor power consumption on the gas network. Linepack depletion during low wind periods was shown to limit the ability of the gas network to fully supply gas-fired generators.     

Sustainable energy planning based on a stand-alone hybrid renewableenergy/hydrogen power system: Application in Karpathos island, Greece

This study presents the sustainable planning of a renewables-based energy system, which aims to fulfil the electric needs of the island by replacing the existing diesel generators with new wind farms, photovoltaic installations and hydrogen production systems. Electric system design and least cost planning analysis were concluded using historic data from both demand and supply sides. An optimal “sustainable island” scheme should ensure 100% use of renewable energy resources for power generation, while hydrogen production is ideal for covering storage and transportation needs. Due to its morphology and scale, Karpathos applies perfectly for wind and solar energy systems, due to increased solar resource (about 1790 kWh/m².year of global irradiation) and high wind potential (average of 9 m/s in specific locations). Therefore, this case study examines an increase in RES penetration up to 20% in the electric energy mixture, a hydrogen production plan just for the needs of transport and a more aggressive, 100% renewables scheme that ensures a self-fulfilling energy system based on indigenous renewable resources.     

Wind energy in Vietnam: Resource assessment,development status and future implications

The aim of this study is to estimate the technical potential of wind energy in Vietnam and discuss strategies for promoting the market penetration of wind energy in the country. For the wind resource assessment, a geographical information system (GIS)- assisted approach has been developed. It is found that Vietnam has a good potential for wind energy. About 31,000 km² of land area can be available for wind development in which 865 km² equivalents to a wind power of 3572 MW has a generation cost less than 6 US cents/kWh. The study also proves that wind energy could be a good solution for about 300,000 rural non-electrified households. While wind energy brings about ecological, economic and social benefits, it is only modestly exploited in Vietnam, where the main barrier is the lack of political impetus and a proper framework for promoting renewable energy. The priority task therefore is to set a target for renewable energy development and to find instruments to achieve such a target. The main instruments proposed here are setting feed-in tariff and providing investment incentives.     

Economic viability and production capacity of wind generated renewable hydrogen

Generally, wind to power conversion is calculated by assuming the quality of wind as measured with a Weibull probability distribution at wind speed during power generation. We build on this method by modifying the Weibull distributions to reflect the actual range of wind speeds and wind energy density. This was combined with log law that modifies wind speed based on the height from the ground, to derive the wind power potential at windy sites. The study also provides the Levelized cost of renewable energy and hydrogen conversion capacity at the proposed sites. We have also electrolyzed the wind-generated electricity to measure the production capacity of renewable hydrogen. We found that all the sites considered are commercially viable for hydrogen production from wind-generated electricity. Wind generated electricity cost varies from $0.0844 to $0.0864 kW h, and the supply cost of renewable hydrogen is $5.30 to $ 5.80/kg-H₂. Based on the findings, we propose a policy on renewable hydrogen fueled vehicles so that the consumption of fossil fuels could be reduced. This paper shall serve as a complete feasibility study on renewable hydrogen production and utilization.     

Design for renewable energy systems with application to rural areas in Japan

This study uses optimization modeling to study efficient ways to integrate renewable energy systems to provide electricity and heat in rural Japan. The model provides minimum cost system configuration and operation taking into account hour-by-hour energy availability and demand. Grid electricity is available to rural areas of Japan, but it is relatively expensive. Local renewable energy generation can be economic while using grid electricity to compensate for the intermittency of the renewable generation. In the model, renewable electricity can be provided by a combination of wind, photovoltaic, and biomass. Heat can be provided by petroleum, LPG, and geothermal heat pumps (GHPs). We find that due to the relatively high cost of grid electricity, there is significant penetration of wind generation. In turn, the penetration of wind creates economic conditions that encourage GHP penetration. The integrated renewable system reduces the annual cost of the entire system by 31%, and reduces the carbon emissions by 50%.