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The Renewable Energy (RE) Data Explorer, developed by the National Renewable Energy Laboratory, is an innovative web-based platform that allows users to visualize and analyze renewable energy potential. The RE Data Explorer informs prospecting, integrated planning, and policymaking to enable low emission development.
The transient dynamics of conventional power systems are dominated by synchronous generators, and low-inertia inverters serve as the primary interface between power systems and renewable energy resources. Increasing penetration levels of inverter-interfaced generation are impacting the transient dynamics of power systems. In this paper, we attempt to quantify these impacts at different penetration levels. An elementary system including one inverter, one synchronous generator, and one load is studied under different parameter variations to assess the transient dynamics of the system. To quantify transient stability, the post-fault regions of attraction of the system are estimated by the sample-based basin stability approach with parallel computing technology. The simulation results suggest that different inverter penetration levels, inertias of the generator, inverter controller gains, and phase-locked loop controller gains have a clear impact on the regions of attraction as well as on the transient dynamics of proposed systems.
Electricity systems around the world are decarbonizing, driven by reductions in the cost of renewable energy and encouraged by supportive regulatory policy. Electricity market designs are increasingly being tested to ensure that the bulk power system can deliver reliable, cost-effective energy to all consumers.
This paper considers power distribution systems featuring renewable energy sources (RESs), and develops a distributed optimization method to steer the RES output powers to solutions of AC optimal power flow (OPF) problems. The design of the proposed method leverages suitable linear approximations of the AC-power flow equations, and is based on the Alternating Direction Method of Multipliers (ADMM). Convergence of the RES-inverter output powers to solutions of the OPF problem is established under suitable conditions on the stepsize as well as mismatches between the commanded setpoints and actual RES output powers. In a broad sense, the methods and results proposed here are also applicable to other distributed optimization problem setups with ADMM and inexact dual updates.
A key step towards a carbon-neutral future could be reached through dispersed power grids, featuring networks of local-scale renewable energy and battery storage plants. To prevent these power grids from damaging themselves and their surroundings when electrical faults arise, they must be integrated with ‘circuit breakers’, which temporarily interrupt the current flowing through them. However, currently available circuit breakers cannot handle the medium-voltage direct currents best suited for these grids. Through an innovative new circuit breaker design, Steve Schmalz and his colleagues at Eaton Corporation, the Illinois Institute of Technology (IIT), Virginia Tech and the National Energy Technology Laboratory (NETL), hope that this challenge will soon be overcome.
Marine renewable energy (MRE) is in the early stages of contributing to the energy portfolios of the US and many other nations around the world. Although many MRE developers are designing devices that will harvest energy to contribute to the electrical grid from waves, tides, and ocean currents, a number of other promising maritime markets could be supplied with MRE power at sea. These maritime markets are often less price sensitive than utility-scale electricity markets and can handle some degree of intermittency. Some of the promising maritime markets that could benefit from co-located power generation include ocean observation nodes, underwater recharge of autonomous vehicles, desalination of seawater for remote coastal areas, offshore aquaculture, shoreline protection and electricity generation, providing electricity and freshwater following coastal emergencies, providing power to islanded and isolated communities, powering and cooling nearshore of underwater data centers, recharging of electric surface vessels, and personal charging of electronics. Pairing of MRE power generation with these and other maritime markets is in the early stages, but the potential for synergy and growth of MRE coupled to these markets is promising.
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This paper discusses challenges that relate to assessing and properly incentivizing the resources necessary to ensure a reliable electricity system with growing penetrations of variable generation (VG). The output of VG (primarily wind and solar generation) varies over time and cannot be predicted precisely. Therefore, the energy from VG is not always guaranteed to be available at times when it is most needed. This means that its contribution towards resource adequacy can be significantly less than the contribution from traditional resources. Variable renewable resources also have near-zero variable costs, and with production-based subsidies they may even have negative offer costs. Because variable costs drive the spot price of energy, this can lead to reduced prices, sales, and therefore revenue for all resources within the energy market. The characteristics of VG can also result in increased price volatility as well as the need for more flexibility in the resource fleet in order to maintain system reliability. Furthermore, we explore both traditional and evolving electricity market designs in the United States that aim to ensure resource adequacy and sufficient revenues to recover costs when those resources are needed for long-term reliability. We also investigate how reliability needs may be evolving and discuss how VG may affect future electricity market designs.
Environmental concerns and depletion of traditional energy lead to the booming development of renewable distributed generation (RDG) in the past decade. However, due to intermittent nature of renewable energy sources, to what extent RDG could provide capacity to power systems becomes a critical issue to the utility company when implementing long-term system strategic (generation expansion) planning. On the other hand, in a smart-grid frame, the popularization of different varieties of demand-side resources enables the system to operate at more flexible modes ever before. The potential variability in load demand not only introduces additional dynamics and uncertainties to the system, but could also affect the reliability benefits of RDG. Therefore, in practice, to effectively estimate the reliability value of RDG in power systems, the potential interaction between generation- and demand-side must be properly captured. In this paper, a study to assess the capacity credit (CC) of RDG in a context of distributed generation system is performed with consideration of the impacts of demand response (DR). A compound reliability model for DR is presented, which considers the uncertainties involved in both instant response and follow-on load recovery processes. On this basis, an assessment framework for the CC of RDG based on sequential Monte Carlo simulation is developed by which the inter-temporal characteristics of DR resources can be fully captured. The numerical study is implemented based on the IEEE-38 bus test case. The calculation results demonstrate that the CC of RDG would depend on a variety of factors, including penetration level, responsiveness of load demand and the correlations between RDG and DR availability. Also, it is shown that accounting for the underlying effect of DR is of absolute importance, otherwise the CC of RDG might be estimated erroneously in real practices.
The goal of this work was to perform a detailed, sub-hourly analysis of very high penetration scenarios for a single interconnection (the Western Interconnection). The scenarios analyzed for this study included a variety of generation infrastructure buildouts and power system operational assumptions, with three different portfolios of renewable generators. The primary conclusion of this study is that sub-hourly operation of the grid is possible with renewable generation levels between 80% and 90%. Dynamic studies will need to be done to understand any impacts on reliability during contingencies and transient events.
Purpose: This paper discusses an ongoing process to assist with the advancement of worldwide understanding of the environmental effects of marine renewable energy (MRE) through a public, online knowledge management system known as Tethys (https://tethys.pnnl.gov). Understanding potential environmental impacts can reduce expensive monitoring requirements and promote growth of this emerging industry. Approach: Tethys acts as the central repository for information in a landscape where literature and knowledge are scattered and difficult to find, providing access for an international audience of stakeholders and the public. An intuitive and flexible design has been developed over 8 years of operation, pairing content curation with synthesis and engagement to enhance the impact of knowledge management. Findings: Tethys has become internationally recognized and trusted as an honest broker of information. A community of participants that use Tethys resources and contributes content has grown to almost 50,000 people around the world, annually. Engineering and siting challenges continue to stall the deployment and establishment of the MRE industry, but progress has been made towards retiring environmental risks and facilitating progression in deploying and operating devices. Practical Implications: The need for knowledge management is particularly important when information is scattered, as is often the case with emerging industries. Tethys serves as an example of intentional design and intuitive organization for knowledge management. Value of Paper: This paper discusses focused knowledge management methods with international cooperation and public engagement to advance an emerging technical industry.
Public outreach fact sheet about the Los Angeles 100% Renewable Energy Study (LA100), which is the most comprehensive, detailed study done to model an entirely renewable-based power system as complex as LA's.
If the electrochemical upgrading of CO2 is directed at products with the market sizes and environmental footprints of fuels then even very inexpensive, renewable electricity may not be sufficient to permit economic operation. If instead, the upgrading is directed at higher value products, then the size of the markets will likely be too small to offer a significant environmental benefit. An alternative approach would be to use the renewable electricity to ameliorate environmental burdens other than CO2, for example, wet or solid wastes that would otherwise be disposed in a landfill. In all cases there are interesting opportunities to pursue and deploy research on heterogeneous catalysis.
Growing trends in the deployment of inverter-based renewable energy will decrease the inertia and frequency control capability of electric power systems by replacing conventional power plants; thus, the frequency of future power systems might be dynamic. This study proposes a capability-coordinated frequency control (CCFC) scheme of a virtual power plant (VPP) including adjustable-speed pumped storage hydropower (AS-PSH), a wind power plant (WPP), and an energy storage system to support the frequency nadir and reduce the steady-state error of system frequency. The CCFC scheme is based on a hierarchical-control structure in which a CCFC organises the output of local frequency control units. To support the frequency nadir, the CCFC dispatches weighted frequency errors that are proportional to the available headroom of the units; thus, the errors are forwarded separately with a system frequency error to the primary control loop of each unit and thereby arrest the frequency nadir at a higher value than a system without the CCFC. To reduce the steady-state error of the system frequency, the CCFC determines a partial active power command by additionally feeding an integrator of the CCFC with a modified frequency error that depends on the unit with the largest control.
We describe the benefits of immersive flow analysis for three large-scale computational science studies in the field of renewable energy. The studies encompass a range of scales, spanning from the large atmospheric scale of a wind farm to the human scale of an electric vehicle cabin down to the microscopic scale of battery material science. In these studies, users explored the flow patterns and dynamics through immersive particle advection. The integration of high-performance computing with immersive analysis provided a deeper understanding of these systems, helping develop more effective solutions for a sustainable energy future.
The United States Agency for International Development (USAID) Enhancing Capacity for Low Emission Development Strategies (EC-LEDS) program is designing its second phase of assistance to the Government of Mexico (GOM). In preparation for program design, USAID has asked the National Renewable Energy Laboratory (NREL) to assist in identifying options for enabling renewable energy in Mexico and reducing greenhouse gas (GHG) emissions in the energy sector. The NREL team conducted a literature review and consulted with over 20 Mexican agencies and organizations during a two-week temporary duty assignment (TDY) to Mexico to identify gaps, opportunities, and program theme areas for Mexico.