Nuclear Power Closes Output Gap

Electricity output from nuclear power plants fell below 2016 levels in mid March, and the gap has averaged more than 1 BCF of natural gas equivalent since then.  But the extraordinary maintenance and repair season is finally wrapping up, and as of today output is back above 2016 levels.  This represents an important loss of incremental demand for natural gas at a time when it is struggling in the power sector against low aggregate demand, mild weather, renewables, and cost competition against coal.  

Coal to Gas Switching in MISO Region Fades as Nuclear Reactors Return to Service

Weekday market share for natural gas has been strong over the last six weeks in MISO, but the single biggest factor driving that is nuclear capacity factor.  Nuke capacity factor has been well below the prior year for April and May, with average output around 200 GWHD this year, vs 280 last year.

As nukes ramp back up, gas should fade from the mix.

Nuclear Power Output Begins Recovering, But Not Quickly

Nuclear power output rose to an 80.9% capacity factor today, but is running more than ten points below the prior year.  That equates to about 2 BCFD of natural gas replacement value.  This extreme differential should only persist for another two weeks or so, when the gap will begin to close with the end of maintenance season.  

Nuclear Power Capacity Factor Rising But Not Quickly

Nuclear power reactors are returning to service, but they will need to ramp up quickly starting tomorrow if they are to close the near 1 BCFE gap with May 2016:

Nuclear Power Output Lagging 2016 by 1 BCFE

As the maintenance and refueling season approaches an inflection point this week, output from reactors is currently about 1 BCF-gas-equivalent  below last year.  As the graph indicates, reactors were rapidly returning to service in May 2016.  The same directional trend is evident this year, month-to-date.  

Nuclear Power Plant Outages Continue at Nearly 1.5 BCFED Over 2016

Nuclear power plant refueling and maintenance season continues with nearly 1.5 BCFED more power offline than last year at this time.  Outages should bottom out in the next two weeks as plants return to service for summer cooling season.

Nuclear Capacity Factor Drops Sharply, Requiring 1.5 BCFD+ of Extra Gas Power Burn

Substantial new outages over the weekend have resulted in a decline of over 3% in nuclear power output from Friday, and it equates to over 1.5 BCFD of gas replacement vs this date last year:

Nuclear Power Output Stabilizes, Near 2016 Levels

As we move through refueling and maintenance season, nuclear power output levels should continue to drop, but the outages have not outpaced 2016 by much so far.  April should see larger year-on-year differentials, at least that's what is expected.

Nuclear Refueling Begins: Large Drop in US Nuclear Capacity Factor Over the Weekend

Nuclear power output capacity factor dropped from 88% to 82% over the weekend, as units came offline.  That improves the power burn potential for natural gas, and a full gas replacement of the lost nuclear output would see about 1BCFD more gas being burned today than on this day last year.  This imbalance is projected to persist for some time.

Nuclear Power Refueling and Maintenance Season Begins. More Downtime than '16 Expected

A large number of reactors are going down for Spring refueling this year.  Currently the difference between 2016 and 2017 outages isn't significant, but we should see it grow quite a bit over the next 90 days:

Nuclear Power Output Steady at +1 BCFE vs 2016

This week marks the first period since early December that US nuclear power generators maintained a capacity factor substantially above 2016.  Yesterday's factor, 95.6%, was 5% above last year, and the natural gas displacement of this high output is exceeding last year by almost 1 BCFD right now.  

The difference should diminish over the next 3 days, as last year's capacity factor rose sharply during the same period:

Nuclear Power Capacity Factor Rises Above 2016

Nuclear power output is now about 3% higher than last year, equating to about 0.5 BCF less natural gas consumed for power burn:

Nuclear Power Output Fell At This Time Last Year

nuclear power output has been similar to 2016 for the last month.  But after today, the comparisons to 2016 change significantly.  Nuclear output started falling quickly in '16, then recovered briefly after a week, and continued their downward slide into spring maintenance and refueling season.  That may not happen to such an extent this year:

Nuclear Power Output is Identical Year-on-Year

Today's nuclear capacity factor is 95.8%, the same as this date last year.  It has been comparable for the last ten days.  Last year, the capacity factor started falling on Jan 24, with some short term outages that led into the spring refueling and maintenance season in February.  Unless some unplanned maintenance is required, the last week in January of this year could outperform last year, offsetting some gas demand.

The gas equivalent of the difference between this year and last year has been very slight for the last ten days:

Nuclear Power Output Comparable to Last Year

Now that maintenance and refueling season is at an end, power output is near capacity, as it was last year at this time.  Today the capacity factor is projected at 96.4%, a new high for the season, and last year it stood at 96.8%.

In terms of natural gas volumes, the difference between today and this day last year is just 0.07 BCFE.  Last year, the capacity factor began declining about this time, so we may be facing a relative surplus if there are no unplanned maintenance events.

Nuclear Power Output Steady, Slightly Below Last Winter

Nuclear power output in the continental US has been level over the past 9 days, about 1% below last year.  This is a change from the first part of winter, where output was outpacing '15.  However, this was the high water mark for nuclear power generation last year, and reactors began to go offline on Jan 8th, so we may again experience a surplus of electricity from nukes.

On a gas equivalent basis, it adds up to about 2 BCF less fossil fuel generation per week at the current level:

Nuclear Power Generation: Capacity Factor Continues Below 2015 Level by 1.5%

Nuclear power output rose slightly over the last week, to 95.3% of rated capacity today.  Thus it sits 1.5% below 2015 as of December 27th:

The impact, in terms of natural gas demand offset, is roughly 0.3 BCFD, so slightly more natural gas is being consumed than last year, and the difference is likely to be small through the winter, with most refueling complete for the season.  But the difference is meaningful in comparison to November, when 2016 capacity factors were much above 2015, and gas demand was suppressed to the tune of 1 BCFD average for the month:

Nuclear Power Output Falls Below 2015

More reactors are out of service now than in 2015, and for the first time in months the capacity factor has dropped below last year at this time.  As of today, the fleet is at 94% of capacity.  Last year, it was 2.2% higher.

The difference between last year and this year, in terms of natural gas equivalent, is about 0.43 BCFD.  While that may not seem like much, it is significantly more that we saw in November, when it averaged a -1.26 BCFD, for a 38 BCF monthly total DIFFERENCE.  That had a big impact on gas demand, and the tables are now turned:

US Nuclear Power Output Falls Below 2015

A few reactor units began powering up over the weekend (Oyster Creek, Arkansas Nuclear 1), but a few units also reduced capacity (Pilgrim, Columbia Generating Station), which netted out to a decline in output from Friday by about 0.5%.  

As of today, the natural gas replacement value of outages in 2016 is greater (by 0.01 BCFD) than 2015, and that difference will likely grow over the next week.  

Nuclear Power Output Shrinks

Nuclear reactor status declined slightly today, prolonging the return from maintenance and refueling that has advantaged this power source thus far.  Today's output displaces 0.6 BCF of gas equivalent more than the same day last year: