Electricity Prices, Large-Scale Renewable Integration, and Policy Implications

The impact of wind power generation on the electricity price in Germany

Hydrogen production by wind and solar hybrid power generation is an important means to solve the strong randomness and high volatility of wind and solar power generation. In this paper, the permanent magnet direct-drive wind turbine, photovoltaic power generation unit, battery pack, and electrolyzer are assembled in the AC bus, and the mathematical model of the wind-solar hydrogen storage coupled power generation system and the simulation model in PSCAD/EMTDC are established. An energy coordination control strategy is designed. After simulation, the proposed control strategy can effectively reduce the rate of curtailment of wind and solar power, and stabilize the fluctuation of wind and solar power generation. It verifies that the established model is correct and the control strategy is effective and feasible.

Nowadays, solar and wind power generation is an important part of the power sources in many countries all over the world. However, due to the variability and uncertainty of these sources, stable operation of the power system with large solar and wind power penetration is a big challenge for system operators. In order to enhance the contribution efficiency of solar and wind power in the power market, a strong ancillary service system is essential and must be reasonable priced. The ancillary services considered in this paper are spinning reserve, non-spinning reserve. In addition, a model for calculating and comparing generation costs for energy and ancillary services, with and without penetration of solar and wind power in the power market have been proposed. Consequently, this model has been developed and validated with a case study. The results show that in a power system with large proportion integration of solar and wind power, the energy and ancillary services generation costs for the power system are high. Besides, the feed-in tariffs of solar and wind power are more expensive than the traditional electricity generation, which leads to high locational marginal prices of the electricity market.

This paper assesses the impact of increasing wind and solar power generation on zonal market prices in the Italian electricity market from 2015 to 2019, employing a multivariate regression model. A significant aspect to be considered is how the additional wind and solar generation brings changes in the inter-zonal export and import flows. We constructed a zonal dataset consisting of electricity price, demand, wind and solar generation, net input flow, and gas price. In the first and second steps of this study, the impact of additional wind and solar generation that is distributed across zonal borders is calculated separately based on an empirical approach. Then, the Merit Order Effect of the intermittent renewable energy sources is quantified in every six geographical zones of the Italian day-ahead market. The results generated by the multivariate regression model reveal that increasing wind and solar generation decreases the daily zonal electricity price. Therefore, the Merit Order Effect in each zonal market is confirmed. These findings also suggest that the Italian electricity market operator can reduce the National Single Price by accelerating wind and solar generation development. Moreover, these results allow to generate knowledge advantageous for decision-makers and market planners to predict the future market structure.

Volatility of electricity price in Denmark and Sweden

The battery energy storage system (BESS) is the current typical means of smoothing intermittent wind or solar power generation. Such BESS hybrid power systems require a suitable control strategy that can effectively regulate power output levels and battery state of charge (SOC). This paper presents the results of a wind/PV/BESS hybrid power system simulation analysis under taken to improve the smoothing performance of wind and Photovoltaic (PV) power generation and the effectiveness of battery SOC control. A wavelet based power smoothing method is presented for reducing output power fluctuations of wind/PV hybrid power generation systems and regulating the battery SOC. The effectiveness of the proposed method was verified using MATLAB/SIMULINK software.

Impacts of large-scale wind and solar power integration on California׳s net electrical load

Many sources of renewable energy, including solar, wind, and ocean wave, offer significant advantages such as no fuel costs and no emissions from generation. However, in most cases these renewable power sources are variable and non-dispatchable. The utility grid is already able to accommodate the variability of the load and some additional variability introduced by sources such as wind. However, at high penetration levels, the variability of renewable power sources can severely impact the utility reserve requirements. This paper presents an analysis of the interaction between the variability characteristics of the utility load, wind power generation, solar power generation, and ocean wave power generation. The results show that a diversified variable renewable energy mix can reduce the utility reserve requirement and help reduce the effects of variability.

One way to mitigate the variability of wind and solar power generation is to install the corresponding plants in nearby locations. For example, in Kuwait, the facility at Shagaya Renewable Energy Park is located in a desert area with both photovoltaic panels and wind turbines that allow the continuous generation of renewable energy throughout the day. The National Center for Atmospheric Research (NCAR) has developed a system to generate probabilistic wind and solar predictions for the Shagaya facility. These predictions are based on the analog ensemble technique that post-processes the wind speed and solar irradiance predictions based on a combination of multiple models including the Weather Research and Forecasting (WRF) numerical model. The ensemble forecasts have 20 members and are generated independently at each wind and solar power production facility. Here we present a method based on the Schaake Shuffle (SS) technique to pair the ensemble members from the independent systems to obtain a unique ensemble prediction of the aggregated wind and solar generation. After reordering through the SS technique, the corresponding paired solar and wind power members can be summed to build a unique ensemble of combined generation that is statistically consistent, as verified by the presented metrics.

To mitigate and adapt to the ongoing climate change, the decarbonization of the economy requires a radical change in our energy production and consumption patterns. A robust finding of existing studies is that renewable energy sources - and more specifically wind and solar power generation - are expected to represent a major share of the power mix in the future. Due to their higher dependency on meteorological variable a better understanding of the variability of VRE outputs across different temporal and geographical scales thus becomes critical. Of particular interest is the study of tight grid conditions with periods of coincidence between low wind and solar output because they will condition flexibility requirements. Our work addresses these research questions based on an analysis of the variability of solar PV and wind power generation capacity factors provided by the Copernicus service C3S energy. The Copernicus C3S energy service deals with the transformation of climate variables (reanalysis, seasonal forecast and climate projection) into energy variables (wind, PV, hydro and energy demand principally). To take into consideration the dependance between the solar and wind resource the combined variability has been evaluated for different wind to PV share. In addition, the coupling of different kind of storage technologies has been anticipated by evaluating the variability on different time scales ranging from hour to month. Finally, focusing on extreme conditions, the results of the variability analysis was synthesized in a couple of boundary conditions that capture the impact of the meteorological variability on estimated joint wind and solar power output. The added value of the proposed methodology will be illustrated for a simple case in France.

The battery energy storage system (BESS) is the current typical means of smoothing intermittent wind or solar power generation. Such BESS hybrid power systems require a suitable control strategy that can effectively regulate power output levels and battery state of charge (SOC); otherwise, a problematically large energy storage capacity is necessary. This paper presents the results of a wind/PV/BESS hybrid power system simulation analysis undertaken to improve the smoothing performance of wind and PhotoVoltaic (PV) power generation and the effectiveness of battery SOC control. A fuzzy-logic-based power smoothing method is presented for reducing output power fluctuations of wind/PV hybrid power generation systems and regulating the battery SOC under the typical conditions. The effectiveness of the proposed method was verified using MATLAB/SIMULINK software.

95/04897 Diffuse solar radiation correlations: Applications to Turkey and Australia

Optimal power dispatch in hybrid power system for medium- and large-scale practical power systems using self-adaptive bonobo optimizer algorithm

The impact of hourly pricing for renewable generation projects in Brazil

As PV and wind power penetrations in utility balancing areas increase, it is important to understand how they will impact net load. We investigate daily and seasonal trends in solar power generation, wind power generation, and net load. Quantitative metrics are used to compare scenarios with no PV or wind, PV plus wind, only PV, or only wind. PV plus wind scenarios are found to have a larger reduction in maximum net load and smaller ranges between maximum and minimum load than PV only or wind only scenarios, showing that PV plus wind can be a beneficial combination.