Study on electrical energy and prospective electricity generation from renewable sources in Australia

Nowadays renewable sources are being used as clean sources to generate electricity and to reduce the dependency on fossil fuels. The uses of renewable sources are being increased in electricity generation and contributed to reduce the greenhouse gas emission. The function of any electrical power system is to connect everyone sufficiently, clean electric power anywhere and anytime of the country. This can be achieved through a modern power system by integrating electrical energy from clean renewable sources into the nation's electric grid to enhance reliability, efficiency and security of the power system. The paper on the status of review the driving force of the generation of renewable energy and proposing electrical energy generation from renewable sources to be ensured at least 20% of total energy of Australia. This paper has been studied the existing electricity generation capacity of Australia from renewable and non-renewable sources. Optimal electricity generation from renewable sources has been examined. The environmental impact of electricity generation from renewable sources has been considered. Under this paper the yearly average wind data of past 20 years and above for some meteorological stations of Australia have been used. The prospective electricity generation from wind turbines and solar photovoltaic panels has been proposed in the paper that will increase electrical energy of the power grid of Australia. It was estimated the capital cost of prospective electricity generation farms from wind and solar PV sources.     

Is the concept of ‘grid parity’ defined appropriately to evaluate the cost-competitiveness of renewable energy technologies?

The concept of ‘grid parity’ has emerged as a key indicator of the competitiveness of renewable electricity generation technologies. In this study, we firstly summarize the definition of the current levelized cost of electricity (LCOE) based methodology for the concept and address its limitation in not taking into account the systematic changes in an electric power system. Secondly, we introduce a bottom-up energy system model based methodology to overcome the limitation. Lastly, we apply the methodology to a case study, the grid parity analysis of solar photovoltaic and onshore wind technologies in the Korean electric power system, to highlight the differences between the results obtained using both methodologies. The results of the study show three implications. First, even if the LCOE of onshore wind is already lower than that of natural gas technologies and the average price of grid electricity, the LCOE is required to be much lower to achieve cost-competitiveness in the electric power system. Second, different technologies might be required to have different LCOE levels to be cost-competitive in the same power system. Third, a policy or plan for the deployment of renewable energy technologies must be harmonized with other policies and plans within the same system.     

The environmental impacts of green technologies in TX

Using detailed electricity consumption and solar generation data from homes in an Austin TX neighborhood between 2013 and 2015, we calculate the environmental benefits of electric vehicles and rooftop solar panels. We estimate time-varying electric grid marginal emissions and water consumption rates in ERCOT through a regression based analysis, and find that emissions and water consumption rates are lowest at high demand times due to those hours' reliance on cleaner natural gas generators. We utilize these emissions and water consumption rates to estimate the avoided GHGs and water consumption from grid electricity that solar panels provide. For electric vehicles, we estimate the net effect of this technology, given the avoided gasoline consumption but increase in grid-related charging. We find that, on average, solar panels avoid approximately 75% of yearly grid-related emissions (0.7 tons CO₂/year per kW of solar capacity) and yearly grid-related water consumption (400 gal/year per kW of solar capacity), where the benefits depend on the orientation of the panels. We also find that electric vehicle deployment results in avoiding up to 70% of fuel-related emissions (3.5 tons CO₂/year) and 60% of fuel-related water consumption (1400 gal/year), though the benefits significantly decrease with the efficiency of the counterfactual vehicle.     

碳中和目标下风电消纳量的影响因素分析

分别从风电产量、需求量、政策、硬件配套4个方面选取8项指标,通过多元回归分析和聚类分析法对全国31个省（市、自治区）年风电消纳情况进行定量分析。结果表明：电价是影响消纳的最主要因素,其次政策、配套设施也有较大影响;聚类分析中第3类地区风电消纳整体情况最优,主要体现在风资源情况、政策导向及电网配套方面。据此探讨未来风电消纳提升路径,并提出相应建议及措施：完善政策与制度支持,加快细节性政策的落实和制定;健全碳市场与可再生能源电力市场交易制度及交易体系,利用电价调控市场影响消纳;加强电网等配套设施建设。     

Exploitation of wind-energy resources in proximity to weak electric grids

Many sites with favourable wind conditions exist in proximity to relatively weak electric grids. This may imply that the sites only to a limited degree can be exploited for wind farms producing electricity due to technical constraints related to the weak grid. The paper first describes these constraints and secondly a number of ways for connecting more wind power to a weak electric grid are presented. The methods and technologies presented are relevant for all projects involving exploitation of wind energy in proximity to weak electric grids.     

Renewable power for China: Past,present, and future

This paper briefly examines the history, status, policy situation, development issues, and prospects for key renewable power technologies in China. The country has become a global leader in wind turbine and solar photovoltaic (PV) production, and leads the world in total power capacity from renewable energy. Policy frameworks have matured and evolved since the landmark 2005 Renewable Energy Law, updated in 2009. China’s 2020 renewable energy target is similar to that of the EU. However, China continues to face many challenges in technology development, grid-integration, and policy frameworks. These include training, research and development, wind turbine operating experience and performance, transmission constraints, grid interconnection time lags, resource assessments, power grid integration on large scales, and continued policy development and adjustment. Wind and solar PV targets for 2020 will likely be satisfied early, although domestic demand for solar PV remains weak and the pathways toward incorporating distributed and building-integrated solar PV are uncertain. Prospects for biomass power are limited by resource constraints. Other technologies such as concentrating solar thermal power, ocean energy, and electricity storage require greater attention.     

Renewable power for China: Past, present, and future

This paper briefly examines the history, status, policy situation, development issues, and prospects for key renewable power technologies in China. The country has become a global leader in wind turbine and solar photovoltaic (PV) production, and leads the world in total power capacity from renewable energy. Policy frameworks have matured and evolved since the landmark 2005 Renewable Energy Law, updated in 2009. China’s 2020 renewable energy target is similar to that of the EU. However, China continues to face many challenges in technology development, grid-integration, and policy frameworks. These include training, research and development, wind turbine operating experience and performance, transmission constraints, grid interconnection time lags, resource assessments, power grid integration on large scales, and continued policy development and adjustment. Wind and solar PV targets for 2020 will likely be satisfied early, although domestic demand for solar PV remains weak and the pathways toward incorporating distributed and building-integrated solar PV are uncertain. Prospects for biomass power are limited by resource constraints. Other technologies such as concentrating solar thermal power, ocean energy, and electricity storage require greater attention.     

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.     

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.     

Electricity generation of hybrid PV/wind systems in Iraq

Renewable resources gained more attention in the last two decades due to persisting energy demand coupled with decrease in fossil fuel resources and its environmental effect to the earth. In Iraq, the electric power generated is not enough to meet the power demand of domestic and industrial sectors. In this article, a hybrid system was proposed as a renewable resource of power generation for grid connected applications in three cities in Iraq. The proposed system was simulated using MATLAB solver, in which the input parameters for the solver were the meteorological data for the selected locations and the sizes of PV and wind turbines. Results showed that it is possible for Iraq to use the solar and wind energy to generate enough power for some villages in the desert or rural area. It is also possible to use such a system as a black start source of power during total shutdown time. Results also indicated that the preferred location for this system is in Basrah for both solar and wind energy.     

Power system decarbonisation with Global Energy Interconnection – a case study on the economic viability of international transmission network in Australasia

The electric energy system in Indonesia is undergoing with the challenges of fast-increasing electricity demand, carbon constraints, and rising costs. Using our model of the Australian and Indonesian electrical grids (either separately or interconnected) that incorporates operational flexibility in capacity expansion planning, we first show that meeting the projected demand for Java and Bali—the main Indonesian grid, with 100% locally integrated renewables by 2050 would be challenging. However, a submarine high-voltage DC (HVDC) link connecting Indonesia’s Java-Bali power grid to the Australian National Electricity Market (NEM) grid through the Northern Territory would help alleviate this situation, given Australia’s abundant renewable energy resources. Then, our model reveals that the Australian NEM could also profit from additional renewables if connected to the Northern Territory through a ground HVDC transmission line to gather intermittent wind and solar generation, which would be curtailed otherwise if unused by Indonesia through the submarine link. Despite the expensiveness of long HVDC links, the wholesale electricity cost of the integrated 100% renewable Australasia power system could be reduced by over 16%, from $AUD177/MWh with only local renewables to $AUD148/MWh with integrated HVDC transmission. The model retrieved the optimal international HVDC link with capacity of 43.8 GW, and the optimal regional HVDC transmission line with a capacity of 5.5 GW. To the best of our knowledge, this is the first detailed model on power system decarbonisation planning for both Australian NEM and Indonesian Java-Bali power grid considering HVDC interconnections.     

Large-scale integration of wind power into different energy systems

The paper presents the ability of different energy systems and regulation strategies to integrate wind power. The ability is expressed by the following three factors: the degree of electricity excess production caused by fluctuations in wind and Combined Heat and Power (CHP) heat demands, the ability to utilise wind power to reduce CO₂ emission in the system, and the ability to benefit from exchange of electricity on the market. Energy systems and regulation strategies are analysed in the range of a wind power input from 0 to 100% of the electricity demand. Based on the Danish energy system, in which 50% of the electricity demand is produced in CHP, a number of future energy systems with CO₂ reduction potentials are analysed, i.e. systems with more CHP, systems using electricity for transportation (battery or hydrogen vehicles) and systems with fuel-cell technologies. For the present and such potential future energy systems different regulation strategies have been analysed, i.e. the inclusion of small CHP plants into the regulation task of electricity balancing and ancillary grid stability services and investments in electric heating, heat pumps and heat storage capacity. The results of the analyses make it possible to compare short-term and long-term potentials of different strategies of large-scale integration of wind power.     

The economics of large-scale wind power in the UK A model of an optimally mixed CEGB electricity grid

Previous calculations of the economics of large-scale wind power have been generally limited to the evaluation of the marginal cost of energy, assuming that the addition of a wind farm to an electricity grid does not change the mix of base, intermediate and peak load plant in that grid. Here a simple but powerful numerical generation planning model has been constructed for grids containing wind farms and three classes of thermal power station, but no storage. Electricity demand and available power are specified by empirically based probability distribution functions and the plant mix which minimizes the total annualized costs of the generating system is determined. Capacity credit of wind power is automatically taken into account in the optimization. Using the model, the breakeven costs of wind energy in a model British CEGB grid, containing coal, nuclear, oil and wind driven power plant, are evaluated under various conditions. For a wide range of parameter values, large-scale wind power is likely to be economically competitive in this grid.     

Heating with wind: Economics of heat pumps and variable renewables

With the growth of wind and solar energy in electricity supply, the electrification of space and water heating is becoming a promising decarbonization option. In turn, such electrification may help the power system integration of variable renewables, for two reasons: thermal storage could provide low-cost flexibility, and heat demand is seasonally correlated with wind power. However, temporal fluctuations in heat demand may also imply new challenges for the power system. This study assesses the economic characteristics of electric heat pumps and wind energy and studies their interaction on wholesale electricity markets. Using a numerical electricity market model, we estimate the economic value of wind energy and the economic cost of powering heat pumps. We find that, just as expanding wind energy depresses its €/MWh_el value, adopting heat pumps increases their €/MWh_el cost. This rise can be mitigated by synergistic effects with wind power, “system-friendly” heat pump technology, and thermal storage. Furthermore, heat pumps raise the wind market value, but this effect vanishes if accounting for the additional wind energy needed to serve the heat pump load. Thermal storage facilitates the system integration of wind power but competes with other flexibility options. For an efficient adoption of heat pumps and thermal storage, we argue that retail tariffs for heat pump customers should reflect their underlying economic cost.     

Power generation of solar PV systems in Palestine

In Palestine, the electric power generated is not enough to meet the power demand of domestic and industrial sectors. In this article, a PV system of 220 kW peak was proposed as a renewable resource of power generation for grid connected applications in residential quarter in north Palestine. The proposed system was simulated using MATLAB solver, in which the input parameters for the solver were the meteorological data for the selected location and the size of PV panels. Results showed that it is possible for Palestine to use the solar energy to generate enough power for some villages or rural area. It is also possible to use such a system as a black start source of power during total shutdown time. Results also indicated that solar PV systems can be more economical than grid electricity.     

分布式风光储发电系统与无电人口供电

国家电网公司投资建设并已成功投运的蒙东陈巴尔虎旗微网项目切实为当地居民解决了用电难问题.同时,项目的实施也为国家智能微网建设提供了宝贵的经验.分布式风光储发电系统为解决无电区人口供电问题提供了可行的解决方案,尤其是内蒙、新疆等风资源、光资源较好的地区.     

Levelized and environmental costs of power-to-gas generation in Germany

The transformation to a greener energy system leads to new challenges, as wind and solar power are not always available. A solution for this challenge is the generation of synthetic natural gas (SNG) and hydrogen from (surplus) wind and solar power, so that the green gases can be stored in the natural gas grid long-term and be used for electricity generation when wind and solar power are not accessible. This solution is especially of interest if the storage infrastructure is already in place, as in Germany, since investment costs can be avoided. Because of that, the study investigates the levelized cost of SNG and hydrogen generation in Germany applying the cost estimation method by Rubin et al. For the investigation, different water electrolysis technologies (alkaline electrolysis, polymer exchange membrane, and solid oxide electrolyzer cell with a size of 1 and 100 MW) and energy scenarios (8,000 h grid, 2,000 h grid, wind, and solar) are contemplated. Besides that, the environmental costs of SNG and hydrogen generation in Germany are investigated due to the increasing importance of these costs for society and companies. The author concludes that the levelized costs of SNG and hydrogen are far too high compared to peer studies, as more cost factors have been considered after applying the method by Rubin et al. In terms of the environmental costs, the use of Germany's grid electricity is not recommended for SNG and hydrogen generation since the generation from wind and solar power is more environmentally friendly, whereby wind power is preferable over solar power.     

The effects of vehicle‐to‐grid systems on wind power integration

Renewable energy portfolio standards have created a large increase in the amount of renewable electricity production, and one technology that has benefited greatly from these standards is wind power. The uncertainty inherent in wind electricity production dictates that additional amounts of conventional generation resources be kept in reserve, should wind electricity output suddenly dip. The introduction of plug‐in hybrid electric vehicles into the transportation fleet presents an possible solution to this problem through the concept of vehicle‐to‐grid power. The ability of vehicle‐to‐grid power systems to help solve the variability and uncertainty issuess in systems with large amounts of wind power capacity is examined through a multiparadigm simulation model. The problem is examined from the perspectives of three different stakeholders: policy makers, the electricity system operator and plug‐in hybrid electric vehicle owners. Additionally, a preliminary economic analysis of the technology is performed, and a comparison made with generation technologies that perform similar functions. Copyright © 2011 John Wiley & Sons, Ltd.     

The influence of generation mix on the wind integrating capability of North China power grids: A modeling interpretation and potential solutions

The large-scale wind power development in China has reached a bottleneck of grid integrating capability. As a result, excess wind electricity has to be rejected in the nighttime low demand hours, when the wind power is ramping up. To compensate for the fluctuation of wind power, new coal-fired power plants are being constructed along with the big wind projects in the North China grids. This study analyzed why adding coal-fired generation cannot remove the bottleneck of wind integration by modeling the operating problem of the wind integration. The peak-load adjusting factor of the regional grid is defined. Building more coal-fired power plants will not increase the adjusting factor of the current grid. Although it does help to increase the total integrated wind power in the short term, it will add difficulties to the long-term wind integration. Alternatively, the coordinated resource utilization is then suggested with the discussion of both the effective pumped hydro storage and the potential electric vehicle storage.     

Analysis of solar photovoltaic and wind power potential in Afghanistan

Afghanistan has a need for increased access to energy to enable development. In this paper we analyze the potential for large-scale grid-connected solar photovoltaic (PV) and wind power plants in two of Afghanistan's most populous provinces (Balkh and Herat) to meet a large fraction of growing electricity demand. The results presented here represent the first quantitative analysis of potential capacity factors and energy yields of power plants in the country using measured wind speed and typical solar radiation data. Variability of resources is also investigated by comparing temporal profiles with those of electricity demand, using residual load duration curves to determine penetration and curtailment levels for various demand scenarios. We show that solar PV and wind power plants in two provinces could achieve penetration levels of 65%–70% without significant curtailment, which in turn would mean less reliance on unpredictable and unstable power purchase agreements with neighboring countries, longer life of limited domestic fossil fuel resources, and lower imports of diesel fuel, thus avoiding rising costs and detrimental environmental impacts. Our results point to an alternative development pathway from that of previous recommendations for conventional thermal power plants, controversial hydroelectric projects, and a significant dependence on imported power.