On the History and Future of 100% Renewable Energy Systems Research

Research on 100% renewable energy systems is a relatively recent phenomenon. It was initiated in the mid-1970s, catalyzed by skyrocketing oil prices. Since the mid-2000s, it has quickly evolved into a prominent research field encompassing an expansive and growing number of research groups and organizations across the world. The main conclusion of most of these studies is that 100% renewables is feasible worldwide at low cost. Advanced concepts and methods now enable the field to chart realistic as well as cost- or resource-optimized and efficient transition pathways to a future without the use of fossil fuels. Such proposed pathways in turn, have helped spur 100% renewable energy policy targets and actions, leading to more research. In most transition pathways, solar energy and wind power increasingly emerge as the central pillars of a sustainable energy system combined with energy efficiency measures. Cost-optimization modeling and greater resource availability tend to lead to higher solar photovoltaic shares, while emphasis on energy supply diversification tends to point to higher wind power contributions. Recent research has focused on the challenges and opportunities regarding grid congestion, energy storage, sector coupling, electrification of transport and industry implying power-to-X and hydrogen-to-X, and the inclusion of natural and technical carbon dioxide removal (CDR) approaches. The result is a holistic vision of the transition towards a net-negative greenhouse gas emissions economy that can limit global warming to 1.5°C with a clearly defined carbon budget in a sustainable and cost-effective manner based on 100% renewable energy-industry-CDR systems. Initially, the field encountered very strong skepticism. Therefore, this paper also includes a response to major critiques against 100% renewable energy systems, and also discusses the institutional inertia that hampers adoption by the International Energy Agency and the Intergovernmental Panel on Climate Change, as well as possible negative connections to community acceptance and energy justice. We conclude by discussing how this emergent research field can further progress to the benefit of society.

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Direct Control Strategy of Real-Time Tracking Power Generation Plan for Wind Power and Battery Energy Storage Combined System

 

To improve the overall economy of the wind-energy storage power station, a direct control strategy is proposed to track the deviation of the wind power plan. Compared with the traditional strategy of wind power fluctuation mitigation, the control strategy in this paper can change the charge and discharge power of energy storage in real-time according to the deviation of wind power and the state of charge (SOC). When the power of wind power changes suddenly, the strategy can make the valid judgment and prevent control failure, so that Grid-connected power of wind farm in extreme cases can also meet the requirements of the safe and stable operation of the power system. The strategy uses the discrete Fourier transform (DFT) to analyze the power deviation of the wind farm in the frequency domain and obtains power compensation requirements for different time scales. Energy storage equipment with corresponding characteristics is used to classify control of deviation of wind power. The compensated power deviation can meet the requirements in market competition. At the same time, the power exchange between storage systems is carried out to optimize the state of charge in real-time and make the energy-type energy storage in shallow charge/discharge state, which effectively reduces the repeated regulation of energy storage systems. Finally, this paper establishes a comprehensive economic benefit model of the energy storage system. Combining the Markov Chain Monte Carlo method (MCMC) and backward scenario reduction technology generate multiple scenarios. The calculation results show that the proposed strategy can effectively track the deviation of the wind power plan. Furthermore, prolong the service life of the energy storage system and improve the market competitiveness of wind power.

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