The electricity grid must manage climate change, regardless of the energy source


Last week’s freeze in Texas, which disrupted the lives and safety of millions of people without heat, electricity and water after a snowstorm, led to power outages and a virtual collapse of the state energy network. planners to stress-test distribution networks for high-impact weather scenarios due to climate change, whether the energy is produced from fossil fuels or from renewable sources. So concludes a recent report by the independent, nonprofit Electric Power Research Institute.

“My thoughts are with the employees of EPRI and the millions of Texas residents and businesses struggling to keep their lights, heat and water on during this massive winter storm, during a global pandemic, ”said EPRI President and CEO Dr. Arshad Mansour, last week when the report was officially released, titled Exploration of the impacts of extreme events, combustible natural gas and other contingencies on resource adequacy. “Much of our economy is already powered by the power sector, but as more of our economy becomes dependent on electricity and our grid continues to incorporate more low-carbon renewable resources, we need to change. how we rate the reliability of our system. “

Dr Mansoor applauded the Texas and Southwestern utilities’ dedication to “responding effectively and generously to increasing weather events, which we no longer call an anomaly.” With this in mind, he added, the realities of climate change are prompting some grid operators to look at system planning and generators in a new way, to assess preparedness for extreme weather conditions at the level of the grid. central.

“Our existing grid supply and delivery assets need to be strengthened for climate change scenarios, regardless of output – renewables and fossil fuels,” he said. “Extreme weather events had a negative impact on all types of production, some more than others, compared to the production expected in the ERCOT [Electric Reliability Council of Texas] resource adequacy planning. Finally, a wider interconnection with other systems through a new transmission will increase access to various resources and fuel supplies and is an essential part of a resilient network that accommodates more low carbon resources. “

Billion dollar weather events

Their report highlighted two central concerns that energy planners should address in relation to “High impact, low frequency” (HILF) events, such as the Texas grid failure. First, the increasing frequency and intensity of events that have a significant impact on the electrical system. Second, the correlation of these events, which has led to the likelihood that high impact events are underestimated, when modeled on the basis of available historical frequency data.

EPRI found that extreme weather events, defined as natural disasters, including hurricanes and tropical storms, floods, drought, extreme heat waves, extreme cold fronts, forest fires, winds Severe, tornadoes, thunderstorms, and snow or ice storms, which are unusual compared to the climatological average, caused 52.9% of power outages in the United States from 2000 to 2016. Most of the aforementioned weather phenomena occur more frequently due to climate change. And also occur with greater intensity, geographic coverage and duration.

In addition, the average annual number of “billion dollar” weather events in the United States – that is, disasters causing $ 1 billion in damage – has quintupled from 2.00%. 9 per year in the 1980s to 15 events per year over the past four years. years (2017-2020). The average annual dollar impact of $ 1 billion weather events has increased 8.6-fold since the 1980s, corrected for inflation, from an average of $ 17.8 billion during this period. decade to $ 153 billion from 2017 to 2019.

EPRI admits that part of the increase in “billion dollar weather events” may be due in part to an increase in wealth (eg, home value), population and people who move to geographic areas more prone to the effects of extreme weather events. Yet the non-linear effect of increasing frequency of extreme events, along with greater intensity, geographic coverage, and duration, is a major contributor to dollar damage. This, in turn, has important implications for the energy industry.

EPRI says that in order to accurately project the probabilities of disruptive weather events in the future, systems planning for electrical reliability must incorporate this rate of change into the planning process itself. Historical probabilities of the frequency, intensity, geographic extent and duration of severe weather events should be adjusted upward to account for recent climate trends.

Lessons from the polar vortex

As a previous example, EPRI offers the polar vortex of January 2014, an event of extreme cold covering the regions of the American Midwest, South Central and East Coast, and generating a record demand for electricity in these regions. The cold snap also fueled demand for natural gas, causing a significant amount of gas-fired production to be unavailable due to reductions in natural gas. This “confluence of factors”, notes the EPRI, has led to the depletion of all electrical reserves, the call for demand management tools, voltage reduction measures and, in some cases. , when shedding approximately 300 MW (0.1%) of the total load. shedding ”being synonymous with“ rolling blackouts ”- in the Eastern Interconnector (one of the two largest energy grids in North America) and in ERCOT.

In addition to power outages, record prices for natural gas and electricity were reported during the first quarter of 2014. EPRI cites the 2014 polar vortex as an example of a common mode event: the system Electric has suffered a dramatic simultaneous loss of available generating capacity, and this may not be captured using current standard models to test resource adequacy.

The report notes that the growing dependence of the wholesale power supply system on gas-fired electricity generation has increased the need for improved coordination between wholesale electricity and natural gas markets. This is essential, as the amount of natural gas in power generation is expected to increase dramatically as coal-fired and nuclear power plants are replaced by gas-fired generation capacities. In the past decade alone, the use of natural gas as a fuel for electricity generation in the United States has increased from 969 TWh (26%) to 1,461 TWh (41%).

At the same time, variable power generation from solar and wind power increases the variability of pipeline deliveries to gas generators used to balance the power grid. As a result, the EPRI notes, intraday and even intra-hourly fluctuations in demand for natural gas as a fuel for power generation present reliability risks for gas pipelines and power systems, and will create new challenges for gas pipelines. pipeline operators.



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