High Share Of Renewable Energy Research Articles

Towards improved prosumer participation: Electricity trading in local markets

Local energy markets are a promising way to involve prosumers in the electricity system and activate demand-side flexibility. In this paper, we develop a modeling framework consisting of an optimization for prosumer home energy management systems embedded in a local energy market simulation. To enable an integrated assessment, the local market is linked to a central spot market. For each prosumer, we consider the individual flexibility potential, home storage systems, and demand response of electric vehicles. Using this model, we analyze the costs and benefits of a local market for prosumers in an energy system with a high share of renewable energy. We compare the systemic effects and the potential economic benefits of this local market for prosumers to pure self-consumption and prosumer participation in a central spot market. Applying our model to a case study of 480 prosumers, we show that a system including a local market is beneficial compared to self-consumption from a systemic perspective. However, allowing prosumers to participate directly in a central spot market is more profitable and facilitates the system integration of renewables.

Optimal cooperative model for the security of gas supply on European gas networks

Natural gas infrastructures play a key role in the transition towards the new energy model, with a high share of renewable energies, both ensuring the firm capacity of electric power systems and integrating all energy vectors. The European Union (EU) strongly depends on external natural gas suppliers and is thus particularly vulnerable. In the event of supply problems due to natural phenomena, technical failures or other threats, cooperation between EU countries would be essential to best solve a supply crisis. This study proposes an EU cooperative model to meet the gas demand over a fourteen-day crisis, using a mathematical optimisation approach for resources and infrastructure. The model considers the dynamic management of underground gas storage facilities, limiting daily withdrawal based on the amount of working gas available in each storage facility. The ability of the model to make quick decisions is illustrated in six gas-demand case studies of the European cold wave in January 2017 and hypothetical supply disruptions.

Impact of techno‐economic parameters on the power systems model with high share of renewable energy and energy storage

Impact of techno‐economic parameters on the power systems model with high share of renewable energy and energy storage

Testing for non-linear willingness to accept compensation for controlled electricity switch-offs using choice experiments

With a higher share of renewable energy in the energy production mix, the need for a flexible electricity production, storage and demand increases. At household level, flexibility in the electricity consumption has the potential to mitigate unexpected drastic shortages of electricity in the system. The efficiency of household flexibility depends on the level of compensation needed to make households accept restrictions in their electricity consumption. The present paper contributes to a growing literature estimating the compensation requirements. Using the economic valuation methods choice experiments, we estimate the amount of compensation needed for households to accept contracts, which allow the energy company to remotely switch off the washing machine, laundry dryer and dishwasher in the household. The contracts vary with the number of times the appliances can be switched off in a year and the duration of each switch off event. Households are willing to accept contracts that allow the energy company to turn off individual devices and charge compensation ranging between 4.8 and 99.0 €/year, depending on the type of contract. The compensation level is found to increase exponentially with the number of annual switch-offs and a linearly with the duration of each switch-off.

Flexibility index and decreasing the costs in energy systems with high share of renewable energy

Recent European Green Deal includes decision to become carbon neutral and even carbon negative region in order to tackle the climate crisis. Main technical challenge and a key factor in techno-economic analysis of the energy system of the future, based on variable renewable energy sources, is their variable production and its integration. In order to deal with this problem in long-term energy planning, different approaches have been tried, focusing on overcapacity, storage capacities and sectors coupling with heating and transport. In this research, different flexibility options, storage and demand response technologies are modelled on a national energy systems level. With the case study area modelled in EnergyPLAN model, the goal of the research is to show how each flexibility option influences the economically feasible generation capacities of renewable energy sources, storage technologies and demand response in order to reach a certain share of renewable energy in final energy consumed. To follow the numerous possible configurations of the system, flexibility index for each option and a flexibility vector for each scenario are introduced. Results show which flexibility options play key role in important steps of energy transition to 70%, 80%, 90% and 100% RES energy system.

Integrating high share of renewable energy into power system using customer-sited energy storage

Renewable energy has rapidly advanced in the global energy system in recent decades. The variability of renewable energy causes technical challenges for its integration in the energy system. Therefore, to increase the share of renewable energy, more flexibility is imperative in the power system. Among all the flexibility options, customer-sited energy storage systems could be a promising measure for addressing both grid and consumer needs. To analyse the effect of customer-sited energy storage systems on renewable energy integration, an integrated power generation and customer-sited energy storage systems expansion planning model is proposed here. The model features high time resolution, operational details of power generation units and energy storage system, as well as load dispatch optimisation. The expansion and operation of the energy storage systems are based on the objective of reducing the total power system costs. Sichuan Province in China is taken as a case study because of its abundant renewable energy resources and increasing renewable energy share in the power system. The following conclusions are drawn: 1) customer-sited energy storage could partially replace coal power plants to provide flexibility for integrating a high share of renewable energy into the power system; 2) CO2 emissions can be significantly reduced at a cost of $30 per tonne; 3) customer-sited energy storage systems cannot gain profits based on the current storage cost and electricity market policy. To enhance the development of customer-sited energy storage systems, storage costs need to be reduced further with technology improvement and policy support. Meanwhile, the electricity market mechanism should be improved to add more incentives for customer-sited energy storage systems, such as increasing peak and valley electricity price differences, providing subsidies for energy storage projects, and increasing the capacity price relative to the energy price in the two-part electricity tariff.

A robust PID controller based on linear quadratic gaussian approach for improving frequency stability of power systems considering renewables

This paper proposes a novel robust controller for frequency stabilization of electrical systems taken into consideration a high renewable energy sources (RESs) penetration. The suggested controller, robust PID (RPID) controller, is combination of a proportional–integral–derivative (PID) controller and a linear quadratic gaussian (LQG) controller. Furthermore, the Improved lightning attachment procedure optimization (ILAPO) technique is applied for determining the optimal setting of the parameters of the introduced RPID controller. A studied power system with RESs is used as a test system to justify the performance of the RPID controller. The superiority of the introduced robust controller is verified through a comparison of its performance under system uncertainties with those of other robust controllers presented in the literature. The results elucidate that the RPID controller can effectually enhance frequency stability and guarantee reliable performance for power grids supplied with high share of renewable energy for all studied scenarios. Consequently, the proposed RPID controller purveys creditable for modern power systems considering RESs.

Renewable Energy Transition for the Himalayan Countries Nepal and Bhutan: Pathways Towards Reliable, Affordable and Sustainable Energy for All

The Himalayan countries Nepal and Bhutan have been confronted with similar climate change and energy emergencies for quite a long time. Its influence is felt as a barrier in financial, social, infrastructural, and political development. Despite having an enormous amount of renewable energy sources, these countries are unable to fulfil their current energy demand. While the power sector is entirely dependent on hydropower, other sectors depend on fossil fuel imports from India. This study offers a pathway for energy independency, energy for all and transition towards a 100% renewables based energy system. The modelling of the energy sector is done using the LUT Energy System Transition model for a period from 2015 to 2050 in a 5-year time step. This study covers the main energy sectors: power, heat, and transport. Two scenarios are visualised, one considering greenhouse gases (GHG) emissions and the associated mitigation cost and another without these costs, though both scenarios aim at achieving a high share of renewable energy by 2050. A substantial drop in levelised cost of energy is observed for the scenario without GHG emission cost, however, taxing GHG emissions will accelerate the energy transition with the levelised cost of energy on a similar level. It is well possible to transition from 90 €/MWh in 2015 to 49 €/MWh by 2050 for the entire energy system by utilizing indigenous low-cost renewable energy. Solar photovoltaics and hydropower will play a dominant role in 2050, having a share of 67% and 31% respectively. Consequently, this leads to zero GHG emissions. An energy transition towards a sustainable and secure energy system for all by 2050 is well possible in Nepal and Bhutan only through 100% renewable sources and it is both technically and economically feasible despite having substantial limitations in infrastructure and economic development currently.

Multistage Model Predictive Control Co-Risk Dispatch for Coupled Electricity and Heat System

The energy transition can facilitate the rapid development of the coupled electricity and heat system (CEHS), accommodating the higher share of renewable energy. However, uncertain renewable energy sources (RESs) and overlimit risk can bring significant challenges for the safe operation of the CEHS. Considering uncertain RESs integration and overlimit risk within the upper and lower bounds jointly with high probability, the multistage model predictive control (MPC) co-risk dispatch model for the CEHS can be proposed in this paper. The model can hedge against the operational risk for the multistage rolling dispatch. In the context of the multistage real-time risk dispatch, the MPC framework is presented, which contains three processes, autoregressive moving average (ARMA) model prediction process, risk-based optimization process, and penalty-based feedback correction process. In the prediction process, the ARMA method can be employed to accurately predict the RESs power, which is characterized as the merit of the short-term forecast. In the optimization process, the violation risk of overlimit chance constraints caused by the output power fluctuation can be mitigated using the distributionally robust chance-constrained (DRCC) under the Wasserstein ambiguity set. The tractable approximation reformulation can be obtained by adopting the Worst-Case Conditional Value-at-Risk (WC-CVaR) approximation method. In the feedback correction process, penalty-based load shedding and RESs spillage can lower the risk level by minimizing the risk penalty cost. In the numerical case, the risk performance analysis based on the modified Barry Island system is implemented. The analysis demonstrates that the daily average violation probability $V_{p}$ can be mainly affected by the Wasserstein radius $\rho $ while the total cost $C_{obj}$ can be affected by the violation probability $\varepsilon $ . The dispatch energy for the CEHS is obtained using the proposed approach, which outperforms the existing robust optimization (RO) approach.

Day-Ahead Market Modelling of Large-Scale Highly-Renewable Multi-Energy Systems: Analysis of the North Sea Region towards 2050

This paper proposes a mathematical model in order to simulate Day-ahead markets of large-scale multi-energy systems with a high share of renewable energy. Furthermore, it analyses the importance of including unit commitment when performing such analysis. The results of the case study, which is performed for the North Sea region, show the influence of massive renewable penetration in the energy sector and increasing electrification of the district heating sector towards 2050, and how this impacts the role of other energy sources, such as thermal and hydro. The penetration of wind and solar is likely to challenge the need for balancing in the system as well as the profitability of thermal units. The degree of influence of the unit commitment approach is found to be dependent on the configuration of the energy system. Overall, including unit commitment constraints with integer variables leads to more realistic behaviour of the units, at the cost of considerably increasing the computational time. Relaxing integer variables significantly reduces the computational time, without highly compromising the accuracy of the results. The proposed model, together with the insights from the study case, can be especially useful for system operators for optimal operational planning.

Waste heat recovery from a data centre and 5G smart poles for low-temperature district heating network

The city of Espoo, Finland is planning to develop Kera as a green suburb with high level of energy efficiency and low CO2 emissions, using a high share of renewable energy and recycled or reused energy. For reaching this target, in this study, renewable energy resources such as solar, wind and waste heat are investigated for the study region. Two different technologies comprising heat pump (HP) and heat-only boiler (HOB) are investigated to retrieve waste heat from a data centre and LuxTurrim5G smart poles to use in a low-temperature district heating network. We investigate various scenarios to supply the required energy for the HP (which receives electricity from the electricity market, photovoltaic (PV) system, wind turbine (WT) and hybrid PV/WT; 4 scenarios) and HOB (which works with electricity, forest fuel wood, biogas, ammonia, wood pellets and industry wood residue; 6 scenarios). We found that the heat pump scenario is an efficient and cost-effective way to retrieve waste heat from the data centre and 5G smart poles with an LCOE of 3.192 ¢/kWh if electricity is produced by the PV system, and 3.516 ¢/kWh when the heat pump receives its electricity only from the electricity market.

Prospective Environmental Impacts of Passenger Cars under Different Energy and Steel Production Scenarios

The potential environmental impacts of producing and using future electric vehicles (EVs) are important given their expected role in mitigating global climate change and local air pollutants. Recently, studies have begun assessing the effect of potential future changes in EVs supply chains on overall environmental performance. This study contributes by integrating expected changes in future energy, iron, and steel production in the life cycle assessment (LCA) of EVs. In this light, the study examines the impacts of changes in these parameters on producing and charging future EVs. Future battery electric vehicles (BEV) could have a 36–53% lower global warming potential (GWP) compared to current BEV. The change in source of electricity generation accounts for 89% of GWP reductions over the BEV’s life cycle. Thus, it presents the highest GWP reduction potential of 35–48%. The use of hydrogen for direct reduction of iron in steelmaking (HDR-I) is expected to reduce vehicle production GWP by 17% compared to current technology. By accounting for 9% of the life cycle GWP reductions, HDR-I has the second-highest reduction potential (1.3–4.8%). The results also show that the potential for energy efficiency improvement measures for GWP reduction in vehicle and battery manufacture would be more beneficial when applied now than in the distant future (2050), when the CO2 intensity of the EU electricity is expected to be lower. Interestingly, under the same conditions, the high share of renewable energy in vehicle supply chains contributed to a decrease in all air pollution-related impact categories, but an increase in toxicity-related categories, as well as land use and water consumption.

Short- and long-run influence of energy utilization and economic growth on carbon discharge in emerging SREB economies

This work highlights the impact of renewable and non-renewable energy, capital formation, and economic growth on CO2 emissions in the economies that are emerging due to China’s Silk Road Economic Belt (SREB) initiative. In this context, data for 24 SREB economies from 1995 to 2014 are analyzed through the Autoregressive Distributed Lag (ARDL) approach. The results suggest that using a high share of renewable energy to execute economic activities and improve the level of capital formation significantly decreases the rate of CO2 emissions in both the long term and short term in the considered SREB countries. The presence of the Environmental Kuznets Curve and the existence of an inverted U-shaped relationship between economic growth and CO2 emissions are also determined. The negative impact of Gross Capital Formation (GCF) and the negligible effects of trade openness on CO2 discharge are also observed. The negative effect of GCF on carbon emissions suggests either that the SREB economies are investing in low-carbon economic activities or simply that those assets are being produced using cleaner energy sources. It is suggested that these countries should pay more attention to renewable energy resources to improve the environment and maximize the economic benefits of the SREB initiative.

Self-Reinforcing Electricity Price Dynamics under the Variable Market Premium Scheme

We report a potential self-reinforcing design flaw in the variable market premium scheme that occurs if variable renewable energy power plants receiving a premium become price-setting in the market. A high share of renewable energy is a goal of many countries on their transformation path to a sustainable future. Accordingly, policies like feed-in tariffs have been in place for many years in many countries to support investment. To foster market alignment, variable market premia have been introduced in at least 12 European countries and a further dozen additional countries world-wide. We demonstrate both with a mathematical model and different scenarios of an agent-based simulation that the combination of variable premia and a high share of hours in which renewables are price-setting may lead to a self-reinforcing downward spiral of prices if unchecked. This is caused by the market premium opening up the bidding space towards negative prices. We discuss possible objections and countermeasures and evaluate the severity of this market design flaw.

International Practice of Improving Power System Flexibility and Its Enlightenment to China

With the rapid increase in the proportion of renewable energy in the power system, the volatility of renewable energy output has greatly increased the risk of power system operation and brought about the need for power system flexibility. A reasonable market mechanism in the electricity market can stimulate flexibility resources and fully exploit the flexibility of the system, which plays an important role in the efficient and safe operation of the power system. This paper studies several countries or regions that have a high share of renewable energy and have established relatively mature power markets, and then analyzes and compares the power system flexibility needs of these regions and the market mechanisms used to increase flexibility. Finally, the enlightenment of international practice to China based on the current situation is summarized.

The economic synergies of modelling the renewable energy-water nexus towards sustainability

This study investigates the role of the water-energy-nexus in transition plans to achieve a future system with a higher share of renewable energy and lower excess water extraction. Applying a novel nexus approach, an interactive multi-period model is proposed to study the synergies of sustainable water and energy supply planning, taking into account operational flexibility of the water sector and its compatibility with inherent intermittency of variable renewable resources. For investigating synergies in designing both energy systems and water systems together, the path of technology cost reduction is assumed to be a function of experience and knowledge and estimated using two-factor learning curves. The learning-by-searching rate was higher than the learning-by-doing rate for utility-scale wind, photovoltaic and reverse osmosis desalination technologies, ensuring research & development investment can play a chief role in the development of these industries. The levelized cost and capacity factor of photovoltaic and wind resources in the Middle East were calculated using data from 81 projects. The results showed that planning the water and energy sectors as endogenous parts of one integrated system brings potential synergies. The levelized cost of variable renewable energy decreased by 20% and the levelized cost of desalinated water dropped 4%.

Analysis on the demand response potential in hotels with varying probabilistic influencing time-series for the Canary Islands

Abstract Tourism represents a significant portion of the total economic activity of many islands throughout the world. This high level of tourist activity has a substantial impact on the energy and water demand. Previous research into smart energy systems on islands has demonstrated that there is significant potential for hotels to partake in energy demand shifting. However, the total potential of such shifting is influenced by variables such as air temperature and the level of occupancy of the hotels. The objective of this work is to quantify the sensitivity of these parameters and their impact on the overall effectiveness of demand shifting within hotels. The assessment contained within this paper utilises Mixed Integer Linear Programming to determine the dispatch of supply and demand on a case study hotel in the Canary Islands. The results show that highest reduction of fossil fuels is reached in a fully electrified hotel energy system. The potential is assumed as independent from weather and guests’ behaviour. If only PV is used, demand shifting in only one hotel leads to a relative change of the degree of self-sufficiency of 1.6–1.8% but the results visualise a saturation effect for an already high share of renewable energies.

An Integrated Planning Framework for Sustainable Water and Energy Supply

This study aims to reveal the economic, technical, and environmental impacts of different system configurations (centralized or decentralized, components, and technologies) on transition plans to achieve a higher share of renewable energy and desalination supplies for regions facing water scarcity. The main contribution of this research is the comparative evaluation of on-grid decentralized or distributed renewable-powered desalination systems for sustainable water and energy supply planning. Applying a novel nexus approach, an interactive multi-period planning model is developed to highlight synergies and to identify conflicts of planning both energy and water sectors at the same time as endogenous subsystems of one overall system. For studying these synergies in this study, the pace of technology deployment and the path of decline in overall costs are assumed to be a function of experience and knowledge as two-factor learning curves. Using data from 81 projects, the levelized cost and capacity factor of utility-scale photovoltaic and wind supplies in the Middle East were calculated. The results indicate that a scenario with a decentralized water sector and renewable-powered multiple-effect distillation technology has the best overall performance among the proposed scenarios.

Modeling Frequency Dynamics in Unit Commitment With a High Share of Renewable Energy

The power system inertia is gradually decreasing with the growing share of variable renewable energy (VRE). This may jeopardize the frequency dynamics and challenges the secure operation of power systems. In this paper, the concept of frequency security margin is proposed to quantify the system frequency regulation ability under contingency. It is defined as the maximum power imbalance that the system can tolerate while keeping frequency within the tolerable frequency range. A frequency constrained unit commitment (FCUC) model considering frequency security margin is proposed. Firstly, the analytical formulation of system frequency nadir is derived while considering both the frequency regulation characteristics of the thermal generators and the frequency support from VRE plants. Then, the frequency security margin is analytically formulated and piecewise linearized. A novel FCUC model is proposed by incorporating linear frequency security constraints into the traditional unit commitment model. Case studies on a modified IEEE RTS-79 system and HRP-38 system are provided to verify the effectiveness of the proposed FCUC model. The impacts of VRE penetration on system frequency security are analyzed using frequency security margin.

Demand response method for smart microgrids considering high renewable energies penetration

Abstract One of the most important reasons of smart grids (SGs) is renewable energies (REs) increase and demand response (DR). Present methods are not practical in the case of high REs presence in SGs and should be revised. The flexibility of production is low in SGs with high REs penetration, and loads should follow the production. The increase in the domestic controllable loads (DCLs) flexibility compensates the low flexibility in production. As a result, DR is essential in SGs with high share of REs. This study presents a new method for DR with high REs penetration. Also, a new formulation for electrical appliances is provided in this study, including washing machine, dish washer and heating/cooling system. In the proposed method, the RE resources produced power is considered in addition to loads condition. The controllable loads are transferred to the time when the difference between load and RE generated power is maximum (considering the consumers’ welfare). The results show that applying this method will increase the flexibility of consumption and REs penetration in SGs. The study is performed for the Ekbatan residential complex that includes three smart microgrids and a 63/20 kV substation in Tehran, Iran.