The prospective of coal power in China: Will it reach a plateau in the coming decade?

Coal power holds the king position in China's generation mix and has resulted in ever-increasing ecological and environmental issues; hence, the development of the electric power sector is confronted with a series of new challenges. China has recently adopted a new economic principle of the “new economic normal,” which has a large effect on the projection electricity demand and power generation planning through 2020. This paper measures electricity demand based upon China's social and economic structure. The 2020 roadmap presents China's developing targets for allocating energy resources to meet new demands, and the 2030 roadmap is compiled based upon an ambitious expansion of clean energy sources. Results show that electricity demand is expected to reach 7500 TWh in 2020 and 9730 TWh in 2030. Coal power is expected to reach its peak in 2020 at around 970 GW, and will then enter a plateau, even with a pathway of active electricity substitution in place.     

Hydrogen supply scenarios for a climate neutral energy system in Germany

A climate neutral energy system in Germany will most likely require green hydrogen. Two important factors, that determine whether the hydrogen will be imported or produced locally from renewable energy are still uncertain though - the import price for green hydrogen and the upper limit for photovoltaic installations. To investigate the impact of these two factors, the authors calculate cost optimized climate neutral energy systems while varying the import price from 1.25 €/kg to 5 €/kg with unlimited import volume and the photovoltaic limit from 300 GW to unlimited. In all scenarios, hydrogen plays a significant role. At a medium import price of 3.75 €/kg and photovoltaic limits of 300–900 GW the hydrogen supply is around 1200 to 1300 TWh with import shares varying from 60 to 85%. In most scenarios the electrolysis profile is highly correlated with the photovoltaic power, which leads to full load hours of 1870 h–2770 h.     

High resolution modelling of the on‐shore technical wind energy potential in Spain

The potential of on‐shore wind energy in Spain is assessed using a methodology based on a detailed characterization of the wind resource. To obtain such a characterization, high‐resolution simulations of the weather in Spain during 1 year are performed, and the wind statistics thus gathered are used to estimate the electricity‐generation potential. The study reports also the evolution with the installed power of the capacity factor, a parameter closely related to the cost of the generated energy, as well as the occupied land, which bears environmental and social acceptance implications. A parametric study is performed to assess the uncertainties in the study associated to the choice of the characteristic wind‐turbine farm used; and comparisons are provided with other similar studies. The study indicates that the overall technical potential is approximately 1100 TWh/y; and that about 70 GW of installed wind power could operate with capacity factors in excess of 24%, resulting in an annual electricity generation of approximately 190 TWh/y, or 60% of the electricity consumption in 2008. Copyright © 2010 John Wiley & Sons, Ltd.     

Exploring the hypothetical limits to a nuclear and renewable electricity future

This article evaluates whether the world can transition to a future global electricity system powered entirely by nuclear power plants, wind turbines, solar panels, geothermal facilities, hydroelectric stations, and biomass generators by 2030. It begins by explaining the scenario method employed for predicting future electricity generation, drawn mostly from tools used by the International Energy Agency. The article projects that the world would need to build about 7744 Gigawatts (GW) of installed electricity capacity by 2030 to provide 37.2 thousand terawatt‐hours (TWh). Synthesizing data from the primary literature, the article argues that meeting such a projection with nuclear and renewable power stations will be difficult. If constructed using commercially available and state‐of‐the‐art nuclear and renewable power stations today, the capital cost would exceed $40 trillion, anticipated negative externalities would exceed $1 trillion per year, and immense strain would be placed on land, water, material, and human resources. Even if nuclear and renewable power technologies were much improved, trillions of dollars of investment would still be needed, millions of hectares of land set aside, quadrillions of gallons of water used, and material supplies of aluminum, concrete, silicon, and steel heavily utilized or exhausted. Because of these constraints, the only true path towards a more sustainable electricity system appears to be reducing demand for electricity and consuming less of it. Copyright © 2009 John Wiley & Sons, Ltd.     

Hydropower Systems and Hydropower Potential in the European Union Countries

Hydropower is today the most important kind of renewable and sustainable energy. Resources of hydropower are widely spread around the world. Hydro energy is the most reliable and cost effective renewable energy source. It is obvious that among all the renewable energies, hydropower occupies the place in the world, and it will keep this place for many years to come. Hydroelectric energy is responsible worldwide for some 2600 TWh of electricity output per year, which means about 20% of the world's entire electricity demand, making it one of the most reliable and cost effective renewable energy sources. In 2001, the largest hydropower generating countries were Canada (333.0 TWh), the United States (201.2 TWh) and Norway (120.4 TWh). Hydroelectric power consumption in the EU grew by nearly 27% between 1991 and 2001. In 2001, hydro accounted for approximately 5% of total EU power consumption. France is the EU's largest producer of hydroelectricity. In 2001, generation capacity of hydropower was about 25,000 MW in France.     

Optimizing 100%‐renewable grids through shifting residential water‐heater load

A low‐carbon electricity supply for Australia was simulated, and the installed capacity of the electrical grid was optimized by shifting the electricity demand of residential electric water heaters (EWHs). The load‐shifting potential of Australia was estimated for each hour of the simulation period using a nationwide aggregate EWH load model on a 90 × 110 raster grid. The electricity demand of water heaters was shifted from periods of low renewable resource and high demand to periods of high renewable resource and low demand, enabling us to effectively reduce the installed capacity requirements of a 100%‐renewable electricity grid. It was found that by shifting the EWH load by just 1 hour, the electricity demand of Australia could be met using purely renewable electricity at an installed capacity of 145 GW with a capacity factor of 30%, an electricity spillage of 20%, and a generation cost of 15.2 ¢/kWh. A breakdown of the primary energy sources used in our scenario is as follows: 43% wind, 29% concentrated solar thermal power, and 20% utility photovoltaic. Sensitivity analysis suggested that further reduction in installed capacity is possible by increasing the load‐shifting duration as well as the volume and insulation level of the EWH tank.     

我国“十二五”综合资源战略规划的思考

我国经济增长大致呈现9年左右的周期性特征,经历全球金融危机以后,我国经济的冬季将会过去,"十二五"期间我国将会迎来经济的春季、夏季甚至秋季,这是经济发展的较快阶段。我们将进入一个低碳经济、低碳能源、以及低碳电力的时代,这也对我国经济发展提出了严峻挑战。本文采用低碳电力模型,模拟结果显示:2015年我国GDP将达到42万亿元(2005年价)左右,需电量约5.6万亿～5.85万亿kWh,届时需要发电装机12.3亿～12.9亿kW左右,能效电厂约6700万～7600万kW左右(虚拟电厂,即通过需求侧管理可以减少的发电装机)。"十二五"期间能效电厂发电量将达到5074亿kWh(用户节约的电量),可以节约发电用煤1.82亿tce,减少二氧化碳排放4.5亿t,以及其他污染物的排放。建设坚强的智能电网也是我国实施低碳能源战略的重要举措。     

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.     

Role of the GB-France electricity interconnectors in integration of variable renewable generation

The integration of large capacities of wind and solar generation into the France and Great Britain (GB) power systems is expected to pose significant operational challenges. Electricity interconnectors can play a role in facilitating the integration of renewable generation in neighbouring countries by allowing power to flow freely between power systems and therefore smooth the net electricity demand. In this paper, role of the electricity interconnectors in efficient balancing of supply and demand in the France and GB power systems was evaluated in terms of overall reduction in the operational costs and curtailment of renewable generation, and also its impact on operation of gas-fired plants. The value of the France-GB interconnectors was studied for two generation mix scenarios in 2030 using PLEXOS. The outputs of the modelling showed the interconnectors will result in larger amount of wind and solar to be absorbed by both power systems which consequently will reduce overall operational costs and CO₂ emissions. In addition, the interconnectors will reduce burden on gas-fired plants compensating for variation in wind and solar generation. This can have a significant value in operation and required investment of gas networks in both countries.     

Transforming the electricity generation of the Berlin–Brandenburg region,Germany

We present possible steps for Germany's capital region for a pathway towards high-level renewable energy contributions. To this end, we give an overview of the current energy policy and status of electricity generation and demand of two federal states: the capital city Berlin and the surrounding state of Brandenburg. In a second step we present alternative, feasible scenarios with focus on the years 2020 and 2030. All scenarios were numerically evaluated in hourly time steps using a cost optimisation approach. The required installed capacities in an 80% renewables scenario in the year 2020 consist of 8.8 GW wind energy, 4.8 GW photovoltaics, 0.4 GW_el bioenergy, 0.6 GW_el methanation and a gas storage capacity of 180 GWh_th. In order to meet a renewable electricity share of 100% in 2030, approximately 9.5 GW wind energy, 10.2 GW photovoltaics and 0.4 GW_el bioenergy will be needed, complemented by a methanation capacity of about 1.5 GW_el and gas storage of about 530 GWh_th. In 2030, an additional 11 GWh_el of battery storage capacity will be required. Approximately 3 GW of thermal gas power plants will be necessary to cover the residual load in both scenarios. Furthermore, we studied the transmission capacities of extra-high voltage transmission lines in a second simulation and found them to be sufficient for the energy distribution within the investigated region.     

需求侧管理是我国电力可持续发展的重要战略选择

进入21世纪,全社会对电力的依赖程度越来越高,对电力供应的质量也提出了更高的要求。一方面社会的发展客观上要求电力工业必须以一定的规模和速度发展,另一方面受资源和环保因素的制约,发展电力工业的问题进一步显现。因此,需求侧管理是我国电力工业可持续发展的战略选择。需求侧管理具有巨大的市场潜力。我国已有实施需求侧管理的经验,到2020年,减少1亿kW的电力装机是可行的。因此我们必须从电力工业可持续发展的高度,从资源利用最优出发,高度重视需求侧管理工作,使得电力需求侧管理在我国电力工业可持续发展中发挥更大的作用。     

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.     

Turkish aggregate electricity demand: An outlook to 2020

This paper investigates the relationship between Turkish aggregate electricity consumption, GDP and electricity prices in order to forecast future Turkish aggregate electricity demand. To achieve this, an aggregate electricity demand function for Turkey is estimated by applying the structural time series technique to annual data over the period 1960 to 2008. The results suggest that GDP, electricity prices and a UEDT (Underlying Energy Demand Trend) are all important drivers of Turkish electricity demand. The estimated income and price elasticities are found to be 0.17 and −0.11 respectively with the estimated UEDT found to be generally upward sloping (electricity using) but at a generally decreasing rate. Based on the estimated equation, and different forecast assumptions, it is predicted that Turkish aggregate electricity demand will be somewhere between 259 TWh and 368 TWh in 2020.     

Interconnector capacity allocation in offshore grids with variable wind generation

Different capacity allocation regimes have a strong impact on the economics of offshore wind farms and on interconnectors in offshore grids. Integrating offshore generation in offshore grids is currently a subject of discussion for different regions, e.g. the North Sea. A novel question is how the interconnector capacity should be allocated for wind generation and for international power trading. The main difficulty arises from the stochastic nature of wind generation: in a case with radial connections to the national coast, the wind park owner has the possibility of aggregating the offshore wind park with onshore installations to reduce balancing demand. This is not necessarily the case if the interconnector capacity is sold through implicit or explicit auctions. Different design options are discussed and quantified for a number of examples based on Danish, Dutch, German and Norwegian power markets. It is concluded that treating offshore generation as a single price zone within the interconnector reduces the wind operator's ability to pool it with other generation. Furthermore, a single offshore price zone between two markets will always receive the lower spot market price of the neighbouring zones, although its generation flows only to the high‐price market. Granting the high‐price market income for wind generation as the opposite design option reduces congestion rents. Otherwise, compensation measures through support schemes or different balancing responsibilities may be discussed. Copyright © 2012 John Wiley & Sons, Ltd.     

Transmission needs across a fully renewable European power system

The residual load and excess power generation of 30 European countries with a 100% penetration of variable renewable energy sources are explored in order to quantify the benefit of power transmission between countries. Estimates are based on extensive weather data, which allows for modelling of hourly mismatches between the demand and renewable generation from wind and solar photovoltaics. For separated countries, balancing is required to cover around 24% of the total annual electricity consumption. This number can be reduced down to 15% once all countries are networked together with unconstrained interconnectors. The reduction represents the maximum possible benefit of transmission for the countries. The total Net Transfer Capacity of the unconstrained interconnectors is roughly 11.5 times larger than current values. However, constrained interconnector capacities 5.7 times larger than the current values are found to provide 98% of the maximum possible benefit of transmission. This motivates a detailed investigation of several constrained transmission capacity layouts to determine the export and import capabilities of countries participating in a fully renewable European electricity system.     

Some aspects on hydraulic energy and environment in Turkey

Turkey is not rich in petroleum and natural gas resources and is dependent on energy. Electricity generation in Turkey from its own domestic resources is, at present, about 40% and is expected to be at 20% by the year 2020. It has been planned that the maximum capacity for hydraulic and other national resources will be reached by the year 2020. This means that the total electricity generated by domestic resources is to be 245 TWh/yr, and the remaining electricity demand of about 302 TWh/yr for the year 2020 must be ensured by imported resources. In Turkey, hydropower projects are part of integrated water resources development. Most new powerplants will be developed as build, operate and transfer (BOT) or build, own and operate (BOO ) projects with the private sector. It is expected that many foreign investors and financiers will also be interested in the Turkish hydropower market. For a sustainable development the next investments should be made for clean technologies such as hydropower. Depending upon the latest technological developments, other economic and political factors will also affect the quality of the environment.     

IEEE Power Engineering Review

France appears to have the second largest wind energy potential in Europe, after the United Kingdom. According to certain estimates the potential annual production is evaluated at 70 TWh on the land and more than 90 TWh for offshore sites located in an area along the coast, with a maximum width of 10 km and where the sea depth is less than 10 m. This potential production of more than 160 TWh represents approximately 33% of the present electricity generation in France. However, the wind energy potential that will actually be exploitable will be noticeably lower. This paper describes the EOLE 2005 Program, a French national program for the promotion of wind power, launched in February 1996. The targets and incentive measures for wind power development are discussed. The grid connection of wind farms and offshore wind energy are also discussed.     

Joint electricity and carbon market for Northeast Asia energy interconnection

Decarbonization of the electricity sector is crucial to mitigate the impacts of climate change and global warming over the coming decades. The key challenges for achieving this goal are carbon emission trading and electricity sector regulation, which are also the major components of the carbon and electricity markets, respectively. In this paper, a joint electricity and carbon market model is proposed to investigate the relationships between electricity price, carbon price, and electricity generation capacity, thereby identifying pathways toward a renewable energy transition under the transactional energy interconnection framework. The proposed model is a dynamically iterative optimization model consisting of upper- level and lower-level models. The upper-level model optimizes power generation and obtains the electricity price, which drives the lower-level model to update the carbon price and electricity generation capacity. The proposed model is verified using the Northeast Asia power grid. The results show that increasing carbon price will result in increased electricity price, along with further increases in renewable energy generation capacity in the following period. This increase in renewable energy generation will reduce reliance on carbon-emitting energy sources, and hence the carbon price will decline. Moreover, the interconnection among zones in the Northeast Asia power grid will enable reasonable allocation of zonal power generation. Carbon capture and storage (CCS) will be an effective technology to reduce the carbon emissions and further realize the emission reduction targets in 2030-2050. It eases the stress of realizing the energy transition because of the less urgency to install additional renewable energy capacity.     

Offshore transmission for wind: Comparing the economic benefits of different offshore network configurations

It has been argued that increasing transmission network capacity is vital to ensuring the full utilisation of renewables in Europe. The significant wind generation capacity proposed for the North Sea combined with high penetrations of other intermittent renewables across Europe has raised interest in different approaches to connecting offshore wind that might also increase interconnectivity between regions in a cost effective way. These analyses to assess a number of putative North Sea networks confirm that greater interconnection capacity between regions increases the utilisation of offshore wind energy, reducing curtailed wind energy by up to 9 TWh in 2030 based on 61 GW of installed capacity, and facilitating a reduction in annual generation costs of more than €0.5bn. However, at 2013 fuel and carbon prices, such additional network capacity allows cheaper high carbon generation to displace more expensive lower carbon plant, increasing coal generation by as much as 24 TWh and thereby increasing CO₂ emissions. The results are sensitive to the generation “merit order” and a sufficiently high carbon price would yield up to a 28% decrease in emissions depending on the network case. It is inferred that carbon pricing may impact not only generation investment but also the benefits associated with network development.     

创立具有我国特色的能源发展之路

随着经济的快速发展,我国油气的对外依存度日益增加。本文认为,能源供应多元化,能源消费电气化。特别是交通的电气化可以减少对油气的需求,起到以电代油的作用。但我国80%的电能是由燃煤电厂生产的,环境压力很大。对此,本文提出从邻国输入部分电能,既可缓解对油气的压力,又可以提高我国的能源利用效率。初步估算,输入6200亿kWh电量可以替代1亿t石油,提高能效2.73个百分点。