The New York Independent System Operator (NYISO) issued a press release on December 17, 2019 announcing a new wind generation record for the state. I disagree with the tenor of the press release and this post explains why I think it is inappropriate. It was a lost opportunity to educate the public about the magnitude of the effort needed to meet the State’s ambitious clean energy goals.
The press release stated:
Strong winds across New York State over the weekend pushed electricity generated by wind power to a new record.
The new record output of 1,675 megawatts (MW) was set during the 11:00 p.m. hour on Saturday, December 14, eclipsing the previous record of 1,651 MW which was set during the 8:00 p.m. hour on April 26, 2019.
When overall wind production peaked at 1,675 MW on Saturday night, it provided 11% of all energy generation in New York. The record output represents 84% of the 1,985 MW of installed wind capacity in New York State.
One megawatt is approximately the amount of electricity required to supply 800 to 1,000 homes. Interested parties can track the NYISO’s real-time fuel mix on our website, www.nyiso.com.
In my opinion the press release is thinly veiled propaganda support for the Climate Leadership and Community Protection Act (CLCPA) which includes a requirement to eliminate the use of fossil-fueled electric generation by 2040. Announcing this record without qualifying the wind resources of New York gives the impression that the State is on track to meet that target.
Right off the bat note that the “record output represents 84% of the 1,985 MW of installed wind capacity in New York State. Think about that. The State has invested in wind energy and the best they have done is 84% of the total installed. Unfortunately, when you look at the big picture serious problems show up.
I used two sources of data from NYISO to evaluate the existing New York wind energy resource. For an overview I used the annual report that presents load and capacity data including historical and forecast seasonal peak demand, energy usage, and existing and proposed generation and transmission facilities. The Load and Capacity Date Report or Gold Book is a featured report in the NYISO document library. This post and a summary I posted in April 2019 use data in Table III-2 Existing Generating Facilities from those reports to describe the annual wind energy resources available. Note that in 2018 all wind energy came from on-shore facilities.
The NYISO Real-Time Dashboard includes a window for the real-time fuel mix that includes the amount of wind generation being generated in the state. The window also includes a link to historical data. I downloaded data for all of 2018, sorted out the wind production numbers, and then calculated hourly averages to compare with the annual numbers from the Gold Book. I use Statgraphics Centurion software from StatPoint Technologies, Inc. to do my statistical analyses and in this case I loaded the hourly data and calculated frequency distribution statistics.
The NY 2018 Wind Facilities in the NYISO 2019 Gold Book table lists all the New York wind energy facilities. The NYISO table provides the name plate ratings and 2018 net energy produced. I used that information to calculate the annual capacity factor for each facility. Note that there is a wide variation of capacity factors, that the highest is only 35.7%, and the state-wide capacity factor is only 24.5%. In other words, New York wind facilities only provide a quarter of their name plate capacity. So in the best hour wind energy has reached 84% of the nameplate capacity and over the year wind energy only produces only 24.5% of the possible power that could be produced. But wait, there’s more.
Another wind-resource issue is the distribution of the hourly output. The 2018 Hourly Wind Generation (MW) Frequency Distribution document lists frequency distribution data for all of 2018. The histogram of wind output categories shows a skewed distribution such that low output is more frequent than high output. The frequency tabulation for wind table shows that there were 10 hours when none of the 24 wind facilities in the state produced any power and that 32% of the time less than 200 MW per hour was produced. The percentiles indicate that half the time hourly wind output is less than 346 MW and that for 876 hours (the tenth percentile) wind energy provides less than 49 MW of energy.
If New York has to rely on renewable energy in the future it is important to know the frequency distribution of wind at night when solar output is unavailable. I used the New York City sunrise and sunset times and calculated when it was dark. The 2018 Hourly Wind Generation (MW) Frequency Distribution at Night document lists the same statistics as before but only for night time hours. While there was only one hour with no wind output and the frequency of hours with output less than 200 MW was down to 28% there still is a significant number of hours when there is no appreciable renewable energy being generated. The percentiles indicate that half the time at night hourly wind output is less than 367 MW and that for 876 hours (the tenth percentile) wind energy provides less than 65 MW of energy. That means that energy storage is going to be absolutely necessary.
I think that the independent system operator has an obligation to the consumers of the state to tell it like it is. This politically expedient press release did not mention any of the issues associated with wind energy relative to the CLCPA target. Based on my results I am sure they could have easily found a day when the wind resources were weak.
I have no doubt that NYISO knows about these issues. They know that the annual capacity factors are low. I have never seen them publish the distribution of hourly wind output but I have to assume that they have looked at the resource in a similar manner. I did not think it would be as bad as it is, and these results have important implications with respect to energy storage. In an earlier post I estimated how much energy storage would be needed for one example period and the costs are startling.
Advocates for renewable power maintain that it is possible to address the problem of calm winds at one location by simply adding facilities in other locations where the wind is blowing. If that were the case using New York resources the hourly distribution would not show that 5% of the time the total wind energy production for the entire state was less than 24 MW. Furthermore, I suspect that even expanding the location of wind facilities to off-shore New York and adjoining jurisdictions is not going to significantly reduce the number of hours when wind resources are going to have to be supported by energy storage. The fact that night time wind generation also shows significant hours with low levels exacerbates the need for energy storage because we cannot use solar to shave the amount needed.
I am very disappointed that NYISO ignored the opportunity to educate the public about the limitations of New York’s wind energy resource. These results reinforce my position that New York State has to do a comprehensive analysis of the availability of renewable resources to determine a strategy for meeting demand with an all-renewable system. Until that is complete, we are only guessing whether this can be done, much less how much this is all going to cost. The NYISO should be pressing for this analysis and this was an opportunity to explain why it is necessary.