Where Colorado Buffalo alumni, fans and friends come to chat all things CU. Go Buffs!

Off Topic Message Board

Banned-for-life

Joined: 12/03/2016 Posts: 235
Likes: 297


The Texas power grid failure(s): An issue of relying on unreliable sources


The message the American public should have received regarding the Texas ‘Big Chill’ was that power systems can fail catastrophically and that the prevention of future failures depends on having a system with sufficient capacity to reliably meet demand during extreme events. Unfortunately, the ‘media’ has avoided telling this story as it exposes a significant weakness regarding renewables, which is the inability to deliver when needed most. Given Texas is again experiencing power grid issues related to a recent heatwave and the media misreporting it, I thought it was worth revisiting what really went down with the ‘Big Chill’. Apologize for the long-winded summary but I think it is a worthwhile story to understand.

The Texas power grid, like all grids, relies on a mix of energy sources that when broken down by capacity include; 5 GW Nuclear, 10 GW Coal, 45 GW NatGas, 4 GW Solar, and 22 GW Wind. In terms of generation, Nuclear output is fixed, Wind/Solar output a function of the current weather conditions, and Coal/NatGas output a function of any remaining unmet demand. Given this energy mix, the Texas power grid has maximum peak generating capacity of about 86 Giga-Watts (GW) with a reliable on-demand (dispatchable) peak energy capacity of 60 GW.

Events, conditions, and energy output by source leading up to the Texas power grid failure (Feb, 2021) are illustrated in a chart (bottom of page) produced by Scott Tinker (Director of the Texas Bureau of Economic Geology) for an investigative report into the incident. The chart provides an insightful view to the root causes of the failure and the importance of reliability in our energy system.

During the week of Feb 1-8, daytime temperatures were in the mid-sixties and total energy usage hovered around 40 GW per day. Wind and solar made up between 20-to-60 percent of the energy mix depending on the day and time with daily contributions during this period averaging about 16 GW.

On Feb 8, an arctic high-pressure system started to extend across the state with temperatures in Dallas, Texas dropping from the mid-sixties to the mid-teens by the end of the week (Feb 15). During the same time period, energy demand progressively increased from about 40 Gigawatts to appx 65 Gigawatts. The increase in energy demand was largely met by NatGas which increased daily output from 15 GW to 45 GW/max capacity. Coal output also increases to max capacity at about 10 GW. Of particular importance were the abrupt decrease in Wind and Solar output that started on Feb 8, in which daily output dropped from 16 GW to appx 4 GW during the entire week of falling temperatures. The loss of renewable output was related to decreased wind speeds in the case of wind energy, and cloud cover/snow events in the case of solar energy.

On the morning of Feb 15, energy demand spiked to an estimated 75 GW. The surge exceeded available capacity by 10 GW leading to overloads that threatened the stability of the system. In order to avoid a potential statewide crash, local blackouts were implemented to reduce the load. This had the undesired effect of actually furthering reducing energy output with immediate drops in Natgas of 8 GW (from 45), Coal of 2 GW (from 10), and Nuclear of 1 GW (from 5). Drops were due to supply-side effects associated with infrastructure not functioning such as pumping stations and feed trains lacking electricity needed to operate. Incremental losses continued to occur throughout the day, with NG and coal losing an additional 4 GW and 2 GW respectively, as more infrastructure went offline and, in some cases, froze. In terms of renewables, wind energy output went to 0 as turbines froze and solar almost to 0 as another major snow event blanketed the area. By the end of the day on Feb 15th, Total Energy about was about 42 GW, sourced from 32 GW of Natgas, 6 GW of Coal, 4 GW of Nuclear, and Zero from renewables. Its estimated that the winterization of equipment could have help with keeping about 6 GW of energy online (4 GW related to wind, 2 GW related to NatGas) during the crisis but it would not have prevented the crisis from occurring as it did not play a role in demand exceeding supply.

Summary

1. The Texas power grid failure was not the result of any particular part of the system failing, as none technically did. It was simply the result of not having enough reliable capacity to meet demand during an extreme event. Wind energy which had the capacity of 22 GW delivered only a small fraction of that total.

2. Weather-dependent renewables can falter when they are needed most. Extreme hot and cold conditions in the US are associated with high-pressure systems that can cover large portions of the US and may extend for weeks at a time. High-pressure systems are characterized by low wind conditions which leave wind energy out of the mix when needed most. We are seeing a similar setup occurring now with wind energy faltering due to the development of a high-pressure system over most the state.

3. Determining a reliable energy capacity when using renewables like wind and solar is extremely challenging and difficult to forecast. Adding excess capacity helps but increases both cost and associated waste significantly.

[Post edited by Banned-for-life at 06/16/2021 3:05PM]

Posted: 06/16/2021 at 3:04PM



+2

Insert a Link

Enter the title of the link here:


Enter the full web address of the link here -- include the "http://" part:


Current Thread:
  Mpre blackouts this summer. Relying on conservation -- Colo Spgs Buff 06/16/2021 3:51PM
  Is it the liberal influence . . . -- 84Buff 06/16/2021 4:05PM
  My point is, if you design a system reliant on convservation -- Colo Spgs Buff 06/16/2021 4:58PM
  Affordable is subjective -- 84Buff 06/16/2021 5:37PM
  Renewables wasn’t the problem. -- BACKinBLACK 06/16/2021 3:20PM
  An article from April 2021 on wind’s role. -- BACKinBLACK 06/16/2021 10:10PM
  Why not this version of the graph? -- 84Buff 06/17/2021 10:42AM
  Again that graph is based on total capacity. -- BACKinBLACK 06/17/2021 11:09AM
  Where's the entire study? -- 84Buff 06/17/2021 11:32AM
  Relying on Academia to study this? -- 84Buff 06/16/2021 4:01PM
  Just in case you missed this one, -- BACKinBLACK 06/16/2021 11:16PM
  Wow. Kudos. ** -- Colo Spgs Buff 06/16/2021 5:00PM
  People were the reason -- 84Buff 06/16/2021 4:32PM
  A cluster for sure. -- BACKinBLACK 06/16/2021 4:42PM
  Or Rick Perry ** -- Gimme 3 Steps 06/17/2021 12:41AM
  How dare you! ** -- HooYahBUFF 06/16/2021 3:17PM
vm312