By Roger Caiazza

The January 2026 winter storm stressed electric systems across the country. It also offers electric resource planners an opportunity to examine the impacts of future increased use of renewable energy during high-load conditions.  This article takes an initial look at the potential impact of such a weather event on the future New York electric system that relies on wind and solar.

There have been other articles about the January 23-27 winter storm impact on the electric grid.  Isaac Orr and Mitch Rolling described impacts to MISO, ISO-New England, ERCOT, and PJM.  They noted that there were no blackouts due to a lack of power generation possibly because “the storm didn’t bring on the high demand that previous winter storms brought in”.  David Middleton covered the storm impacts on ERCOT noting that fossil generation provided the power when renewables were unavailable. 

This article looks at the storm impacts on the New York grid and how a similar storm would affect the future grid of the state when the Climate Leadership & Community Protection Act (Climate Act) requirements for a 2040 zero-emissions grid kick in.

I relied on two sources of New York Independent System Operator (NYISO) data for this analysis.  New York fuel-mix load data are available at the NYISO Real-Time Dashboard.  The second source of data is the Operations Performance Metrics Monthly Report prepared by the NYISO Operating Committee.  I looked at data from January 22-31, 2026, to bound conditions before the storm and after.  Note that the cold weather went into February but the Metrics Report data for February is not available so I did not include February data in my evaluation.

New York Grid Impacts

The dashboard real-time fuel mix data includes links to current and historical five-minute generation (MW) for energy generated in New York State.  I processed that data to calculate hourly averages as described in a post on my blog.  Figure 1 graphs all the fuel mix hourly data. The relative average fuel mix energy provided over these ten days was nuclear 18%, hydro 14%, and fossil fuels 61% for a total of 93%. Six years after passing the net-zero transition legislation New York only got 7% of its energy over the last ten days of January from wind and solar.

Figure 1: Hourly NYISO Realtime Fuel Mix January 22 to January 31, 2026

I used the January  Operations Performance Metrics Monthly Report for this analysis.  This report includes a graph of net wind and solar performance.  It describes the wind; utility-scale solar, also known as Front of the Meter (FTM) solar; and the rooftop top solar also known as Behind the Meter (BTM) solar total daily production and capacity factors. 

Figure 2: Net Wind and Solar Performance Total Daily Production and Capacity Factors

In New York the winter storm impacts started on the night of 24 January and total snow/sleet accumulation ranged from 8-13” near the coast and 12-17” across the interior.  As the precipitation ended a glaze of freezing rain occurred.  Following the storm there was a period of prolonged sub-freezing weather.  Figure 2 clearly shows the impact of snow on all solar production with no solar production on January 25.

Table 1 consists of three smaller tables.  On the left,  capacity factors derived from Figure 2 are listed for each day of the episode.  At the top, resource capacity (MW) from the Operations Performance Metrics Monthly Report are listed for solar and wind resources.  The main body of the table lists the calculated renewable daily energy (MWh) for each parameter and the renewable percentage of the total system energy that I calculated using the real-time fuel mix data.

Table 1: Capacity Factors Derived from Figure 5, Resource Capacity (MW) from Operations Performance Metrics Monthly Report, and Calculated Renewable Daily Energy (MWh)

The total renewable output in Table 2 is notable.  On average, wind resources counterbalance low winter solar resource availability.  However, during dark doldrums when the wind fails renewable resources plummet.  If such a period occurs after a significant snowstorm, then total renewable resources approach zero.

I have previously described the challenge of the gap between renewable energy production and peak loads and the potential solution.  The New York entities responsible for the electric system all agree that a new category of generating resources called Dispatchable Emissions-Free Resources (DEFR) is necessary to keep the lights on during periods of extended low wind and solar resource availability. The observed eight consecutive days where wind and solar resource availability was less than 6% of the potential capacity is a perfect example of the conditions that necessitate this new resource.

Electric System Projections

I used these results to evaluate projections made for the generating resources necessary to meet the 2040 100% zero emissions electric generation mandate. Table 2 lists the projected 2040 capacity (MW) for four scenarios that have been developed for the 2040 New York electric system.  I have included one scenario from the NYISO, the primary projection scenario from the Scoping Plan that outlined how the Climate Act 2040 mandate could be achieved, and two “Net Zero” scenarios from the draft New York Energy Plan developed last summer.  These scenarios represent four ways to achieve the 2040 mandate for zero emissions electric generation.

Table 2: Projected Electric Resource Capacity (MW) in 2040.

I detailed the process to estimate the impact of this storm on these resources if you are interested in more details.  I estimated the daily energy production for the projected generating resources in Table 2. Daily production equals the capacity in MW times the capacity factor times 24 hours in the day. Capacity factors were derived from the real-time fuel mix or taken from the Operations Performance Metrics Monthly Report data in Table 1. 

I estimated the 2040 daily energy production for each scenario by multiplying those factors by the Table 2 resource capacities.  Table 3 is an example of the daily production for the weather over this period.  Note that consistent with the zero-emissions mandate there are no fossil fuel (Gas and Fuel Oil) emissions.  Consistent with the NYISO projection for the winter peak, no imported hydro generation is included.  I calculated the battery storage energy production by multiplying the projected capacity times four hours (the current default discharge time).  This assumption is included every day but note that if the batteries need to be charged using renewables there are instances where there would be insufficient energy to recharge the batteries.  Finally, note that in this example, no DEFR production was assumed.

Table 3: Daily Production (MWh) for January 22, 2026

The goal was to compare the observed daily observed energy load against the projected energy projection for daily production in Table 3 to see if the resources provided enough energy to cover the observed generation load from the real-time fuel mix data during the conditions of the January 2026 storm.  Using the existing total load I found that weather like five days from Jan 22-31 created conditions in which resources excluding DEFR were unable to provide enough power generation to cover the January 2026 loads.  The NYISO 2025 Load & Capacity Data Report notes that New York electric system is projected to increase winter peaking load due to electrification, primarily from space heating and EVs.  When I accounted for that increase in load, none of the scenarios provided enough power from January 24-31 to prevent blackouts.

These results show that DEFR is necessary. When I included the DEFR resources operating at a capacity factor of 85% most scenarios provided enough generation to cover expected load  Because no DEFR technology has been identified the capacity factor value is arbitrary.  The one scenario exception to this was the “Net Zero B” option that never showed a surplus even with a 100% capacity factor.  My analysis found that at least 20GW of DEFR would be necessary to prevent a generation shortage if these conditions were to occur in 2040 for these capacity projections.

Dark Doldrum and DEFR

The most notable finding in Table 1 is the observation that there were eight consecutive days when the total New York wind and solar production was 6% or less than maximum possible energy production.  This is a perfect example of what the Germans call “Dunkelflaute”.  That term refers to dark doldrum periods when solar is reduced due to the length of day or clouds and there are light winds.  This event was exacerbated by the snowstorm that covered solar panels with enough snow to eliminate production (Figure 2).  Note that most rooftop solar in New York City is essentially flat so snow cover is a significant issue.  In this case the loss of solar was exacerbated by the snow depth, a crust of ice from a glaze of freezing rain that occurred at the end of the storm, and the subsequent period of prolonged sub-freezing weather. Perhaps we should amend the worst weather label to “snowy dark doldrums”.

These conditions are the fundamental driver of the need for DEFR.  It is disappointing that the clean energy advocates have continued to argue that the size of the DEFR gap has been overstated even after all the agencies responsible for electric system reliability argue otherwise.  These results should put those arguments to rest.

Conclusion

Large projected wind and solar capacities do no good when the sun doesn’t shine and the wind doesn’t blow.  During and following the January winter storm there were at least eight consecutive days when the New York total wind and solar production was less than 6% of the capacity available.  These are the conditions that require DEFR.  Without DEFR, intermittent, diffuse, and correlated electric generating resources are not viable.  Given that there is no commercially available DEFR technology available, proceeding under the assumption that one will magically appear is risky.

---

Roger Caiazza blogs on New York energy and environmental issues at Pragmatic Environmentalist of New York.  This represents his opinion and not the opinion of any of his previous employers or any other company with which he has been associated.