Utilities and electric grid coordinators are preparing for a total solar eclipse that is projected to temporarily reduce solar photovoltaic generation across parts of North America this summer.
The 2017 total solar eclipse will be the first in the U.S. in 26 years (since Hawaii 1991), and the first in the lower 48 states since 1979. While the duration of the total eclipse across the U.S. will be roughly 93 minutes, some areas in its path will experience up to 95% of the Sun being obscured.
The eclipse is projected to affect solar PV generation. Solar resources occupy an increasing role in the U.S. electric generating portfolio. Between 2000 and 2016, total U.S. solar capacity increased from 5 megawatts (MW) to 42,619 MW. But as more solar resources are connected to the grid, the potential impact of an eclipse on grid operations may change.
According to a May 1, 2017 presentation to the Board of Governors of the California ISO, the eclipse is projected to reduce solar output in the CAISO region by 4,194 megawatts, while gross load will increase by 1,365 MW. Taking into account estimated wind production, the presentation projects a net load increase of 6,008 MW during the eclipse.
The ramp rate, or speed at which supply and demand will change, is also a factor. The eclipse is projected to diminish solar output by about 70 MW per minute as it approaches totality, and about 90 MW per minute on the return. By contrast, a typical average ramp rate for CAISO might be 29 MW per minute. Thus the eclipse is projected to call for a greater degree of fast-ramping or flexible resources, compared to typical operating conditions.
But according to international electric reliability organization NERC, the August 21, 2017 total solar eclipse "is unlikely to cause any reliability issues to the North American bulk power system."
NERC documented its findings in an April 25, 2017 white paper, A Wide-Area Perspective on the August 21, 2017 Total Solar Eclipse. NERC's report identifies California and North Carolina as the states
most likely to experience the greatest impact from solar production
fall-off from the eclipse. At the same time, NERC recommends "that utilities in all states perform specific studies of the eclipse’s impact of solar photovoltaic power output on their systems and retain necessary resources to meet the increased electricity demand requirements." In particular, NERC notes that generation and system operators may greater visibility into utility-scale solar projects than into behind-the-meter or distributed solar photovoltaic resources, highlighting the need to model all scales of solar development.
Following the 2017 eclipse, the next total solar eclipse is projected to cross North America on April 8, 2024.
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Showing posts with label fast-ramping. Show all posts
Showing posts with label fast-ramping. Show all posts
Report on 2011 New England electricity market
Friday, June 29, 2012
New England electricity markets operated competitively and relatively efficiently in 2011, according to a report filed with federal regulators earlier this week. The 2011 Assessment of the ISO New England Electricity Markets (184-page PDF), prepared by New England's external market monitor, reports on how the market performed last year, with a focus on evaluating efficiency and competitiveness.
ISO New England Inc. is the regional transmission organization covering most of New England. In this role, ISO New England performs three major functions: overseeing operation of New England's bulk power generation and transmission system, administering the region's wholesale electricity markets, and managing regional planning processes. ISO New England is regulated by the Federal Energy Regulatory Commission, and has both internal and external market monitors who review its performance. The internal market monitor is a unit within ISO New England Inc., while the external market monitor is an independent outside consultant. Potomac Economics currently serves as the external market monitor.
Potomac's report found that "the markets performed competitively in 2011". One piece of evidence Potomac used to support this finding is that average energy prices fell 7 percent from 2010 to 2011 (from approximately $53 per MWh in 2010 to $49 in 2011). According to the report, this is due in large part to a decrease in the average price of natural gas. In Potomac's view, lower fuel costs translate to lower prices in a well-functioning, competitive market because fuel costs constitute the vast majority of the marginal costs of most generation. Natural gas pricing decreases were not the only contributor to lower energy prices, according to the report; Potomac also noted that prices fell due to a weather-driven decrease in demand for electricity, stating that, "Average load decreased 1 percent from 2010 to 2011 and 2.5 percent from the summer of 2010 to the summer of 2011, primarily due to milder weather."
Potomac also found that "both the day-ahead and real-time markets operated relatively efficiently in 2011 as prices appropriately reflected the effects of lower fuel prices and load levels." However, the external market monitor found that "real-time prices often do not fully reflect the cost of satisfying demand and maintaining reliability during tight market conditions, particularly when fast-start resources or demand response resources are deployed in the real-time market." As a result, the report recommended a series of changes to the New England markets, including developing pricing changes to allow the actual costs of demand response and fast-start resources to be reflected in prices.
The report was filed with the Federal Energy Regulatory Commission on June 25. It complements the 2011 Annual Markets Report (121-page PDF), released this May by ISO New England's internal market monitor. The internal market monitor's report similarly found that the markets operated competitively in 2011.
ISO New England Inc. is the regional transmission organization covering most of New England. In this role, ISO New England performs three major functions: overseeing operation of New England's bulk power generation and transmission system, administering the region's wholesale electricity markets, and managing regional planning processes. ISO New England is regulated by the Federal Energy Regulatory Commission, and has both internal and external market monitors who review its performance. The internal market monitor is a unit within ISO New England Inc., while the external market monitor is an independent outside consultant. Potomac Economics currently serves as the external market monitor.
Potomac's report found that "the markets performed competitively in 2011". One piece of evidence Potomac used to support this finding is that average energy prices fell 7 percent from 2010 to 2011 (from approximately $53 per MWh in 2010 to $49 in 2011). According to the report, this is due in large part to a decrease in the average price of natural gas. In Potomac's view, lower fuel costs translate to lower prices in a well-functioning, competitive market because fuel costs constitute the vast majority of the marginal costs of most generation. Natural gas pricing decreases were not the only contributor to lower energy prices, according to the report; Potomac also noted that prices fell due to a weather-driven decrease in demand for electricity, stating that, "Average load decreased 1 percent from 2010 to 2011 and 2.5 percent from the summer of 2010 to the summer of 2011, primarily due to milder weather."
Potomac also found that "both the day-ahead and real-time markets operated relatively efficiently in 2011 as prices appropriately reflected the effects of lower fuel prices and load levels." However, the external market monitor found that "real-time prices often do not fully reflect the cost of satisfying demand and maintaining reliability during tight market conditions, particularly when fast-start resources or demand response resources are deployed in the real-time market." As a result, the report recommended a series of changes to the New England markets, including developing pricing changes to allow the actual costs of demand response and fast-start resources to be reflected in prices.
The report was filed with the Federal Energy Regulatory Commission on June 25. It complements the 2011 Annual Markets Report (121-page PDF), released this May by ISO New England's internal market monitor. The internal market monitor's report similarly found that the markets operated competitively in 2011.
FERC Order 755 promotes energy storage
Wednesday, December 21, 2011
New technologies have the promise to help electric grid operators perform the challenging task of balancing supply and demand at all times. This means making sure there the exact amount of electricity is being generated across the region as is demanded by consumers at that very moment. Line losses and the constraints of each local transmission and distribution system add complication. If the grid gets out of balance, problems arise with the electricity's frequency and power quality. In the worst case, failure can lead to cascading blackout, and safety can be at issue.
Historically, the balancing act has involved sending coordinated dispatch instructions to generators and demand response resources. Rules typically guide the grid operator in telling individual generating units to operate at specific levels. For example, flows through hydroelectric turbines can be varied, or fuel can be added to boilers or combustion turbines at a faster or slower rate. Through careful management, these conventional generation resources have been used to balance supply and demand, providing services known as frequency response and frequency regulation.
Though it is partly automated and well-practiced, this conventional resource dispatch process does take some time to take effect. Energy storage technologies such as flywheels, and batteries can not only provide frequency regulation, but can engage and ramp up much faster than conventional resources can. These faster-ramping resources could provide the grid relief in real time, as opposed to ramping up more slowly like conventional generation.
In most US markets, providers of efficient fast-ramping frequency regulation have been compensated the same as when conventional units provide regulation service, even when using fast-ramping resources is more efficient. At times this has meant that conventional resources have been dispatched when fast-ramping ones would have been lower-cost (and less polluting). For these reasons, this October the Federal Energy Regulatory Commission found that the current frequency regulation compensation practices "result in rates that are unjust, unreasonable, and unduly discriminatory or preferential."
In Order No. 755, FERC issued a final rule requiring the grid operators in organized markets to compensate frequency regulation resources based on the actual service they provide. Under Order 755 (123 page PDF), this must include separate payments for capacity (the marginal unit’s opportunity costs of being available) and for your actual performance.
Winners under Order 755 include providers of fast-ramping frequency response. These could include developers and operators of flywheel energy storage companies like Beacon Power, battery storage facilities, and compressed air energy storage, and other resources still in the conceptual phase. Winners also include energy consumers in the markets affected by Order 755, who should benefit from lower costs through improved operational and economic efficiency.
Historically, the balancing act has involved sending coordinated dispatch instructions to generators and demand response resources. Rules typically guide the grid operator in telling individual generating units to operate at specific levels. For example, flows through hydroelectric turbines can be varied, or fuel can be added to boilers or combustion turbines at a faster or slower rate. Through careful management, these conventional generation resources have been used to balance supply and demand, providing services known as frequency response and frequency regulation.
Though it is partly automated and well-practiced, this conventional resource dispatch process does take some time to take effect. Energy storage technologies such as flywheels, and batteries can not only provide frequency regulation, but can engage and ramp up much faster than conventional resources can. These faster-ramping resources could provide the grid relief in real time, as opposed to ramping up more slowly like conventional generation.
In most US markets, providers of efficient fast-ramping frequency regulation have been compensated the same as when conventional units provide regulation service, even when using fast-ramping resources is more efficient. At times this has meant that conventional resources have been dispatched when fast-ramping ones would have been lower-cost (and less polluting). For these reasons, this October the Federal Energy Regulatory Commission found that the current frequency regulation compensation practices "result in rates that are unjust, unreasonable, and unduly discriminatory or preferential."
In Order No. 755, FERC issued a final rule requiring the grid operators in organized markets to compensate frequency regulation resources based on the actual service they provide. Under Order 755 (123 page PDF), this must include separate payments for capacity (the marginal unit’s opportunity costs of being available) and for your actual performance.
Winners under Order 755 include providers of fast-ramping frequency response. These could include developers and operators of flywheel energy storage companies like Beacon Power, battery storage facilities, and compressed air energy storage, and other resources still in the conceptual phase. Winners also include energy consumers in the markets affected by Order 755, who should benefit from lower costs through improved operational and economic efficiency.
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