美国水力发电容量因素呈下降趋势
Sean W D Turner1, Ganesh R Ghimire2, Carly Hansen2
1Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA. turnersw@ornl.gov.
Nature communications
|June 27, 2024
概括
自1980年以来,美国的水力发电容量因素大幅下降,导致大量的发电损失. 非气候因素,而不仅仅是水的可用性,正在推动可再生能源生产的减少.
科学领域:
- 环境科学 环境科学
- 能源系统分析 能源系统分析
- 可再生能源是可再生能源的来源.
背景情况:
- 在过去的50年里,美国水电机队经历了日益增长的环境和监管挑战.
- 这些压力可能限制了从这个关键的可再生能源中整体发电.
研究的目的:
- 分析自1980年以来美国水电机队容量因子的趋势.
- 确定水电发电中观察到的变化背后的驱动因素.
主要方法:
- 对美国610座水电厂 (超过5兆瓦) 的年度能源生产和命名能力的分析.
- 统计分析以确定容量因子下降趋势的意义.
- 评估水供应与其他因素对生产变化的贡献.
主要成果:
- 自1980年以来,美国水电厂的年产能因子下降了80%,达到80%的水平.
- 在三分之二的这些植物中观察到显著的下降趋势 (p < 0.05).
- 自1980年以来,全舰队发电量下降了23%,相当于胡佛大每2-3年退休一次.
- 在只有21%的工厂中,水的可用性解释了能源的减少;非气候因素占主导地位.
结论:
- 美国的水力发电量已大幅减少,原因不仅仅是水资源供应.
- 电厂设备的恶化和非电力目标的运营变化是减少发电量的关键驱动因素.
- 解决非气候因素对于保持和优化水电对能源组合的贡献至关重要.
相关概念视频
Design Example: Analyzing Capacity Contours for Flood Risk Assessment
43
Flood risk assessment involves careful planning and analysis to ensure the safety of communities near water retention structures. Capacity contours are a vital tool in this process, as they illustrate the potential spread of water at specific levels in a given area. In the context of building a bund across a small valley, these contours play a critical role in evaluating the safety of nearby residential areas.In this example, the bund is intended to store stormwater in the valley. The engineers...
43
Hydraulic Jump
70
A hydraulic jump is a sudden rise in fluid depth in open channels, occurring when high-velocity (supercritical) flow transitions to low-velocity (subcritical) flow. This phenomenon requires an upstream Froude number greater than 1, as flows with Fr1<1 remain subcritical, making a hydraulic jump impossible due to the need for negative head loss, which violates thermodynamic principles.The characteristics of a hydraulic jump depend on the upstream Froude number and are classified as...
70
Fast Decoupled and DC Powerflow
183
The fast decoupled power flow method addresses contingencies in power system operations, such as generator outages or transmission line failures. This method provides quick power flow solutions, essential for real-time system adjustments. Fast decoupled power flow algorithms simplify the Jacobian matrix by neglecting certain elements, leading to two sets of decoupled equations:
183
Design Example: Creating a Hydraulic Model of a Dam Spillway
158
Scaled hydraulic models of dam spillways provide a practical way to replicate and study the intricate flow dynamics of these structures. Often built to a 1:15 ratio, these models allow for observing critical water behavior, such as velocity distribution, flow patterns, and energy dissipation.
158
Power Factor Correction
168
The power transmission to a factory involves the transfer of apparent power, a combination of active and reactive power. The power factor measures how effectively electrical power is converted into useful work output. The ratio of the real power (KW) that does the work to the apparent power (KVA) supplied to the circuit.
168
Rapidly Varying Flow
57
Rapidly varying flow (RVF) in open channels is characterized by abrupt changes in flow depth over a short distance, with the rate of depth change relative to distance often approaching unity. These flows are inherently complex due to their transient and multi-dimensional nature, making exact analysis difficult. However, approximate solutions using simplified models provide valuable insights into their behavior.Key Features of Rapidly Varying FlowRVF is commonly observed in scenarios involving...
57


