Scott Luft
@scottluft.bsky.social
Data Manager, Communicator, Advocate for consumers, and nuclear power.
Suddenly, days after Pickering's reactors exited service, Ontario's electricity system operator is worried about capacity this winter.
so... out-of-market capacity contract with US generator (whose nearest facility is a big oil-burner in Oswego).
so... out-of-market capacity contract with US generator (whose nearest facility is a big oil-burner in Oswego).
October 4, 2026 at 12:45 PM
Suddenly, days after Pickering's reactors exited service, Ontario's electricity system operator is worried about capacity this winter.
so... out-of-market capacity contract with US generator (whose nearest facility is a big oil-burner in Oswego).
so... out-of-market capacity contract with US generator (whose nearest facility is a big oil-burner in Oswego).
jumping back to summaries from hourly reporting and estimates including distributed supply, curtailment, and costing, the average rate to last year is similar.
No rate class (A or B and exporters) should be much changed from Sept. 2025.
4/4
No rate class (A or B and exporters) should be much changed from Sept. 2025.
4/4
October 1, 2026 at 3:44 PM
jumping back to summaries from hourly reporting and estimates including distributed supply, curtailment, and costing, the average rate to last year is similar.
No rate class (A or B and exporters) should be much changed from Sept. 2025.
4/4
No rate class (A or B and exporters) should be much changed from Sept. 2025.
4/4
appending a previous monthly generator output data set... record levels of fossil fuels on the IESO (for Sept.)
... and this in the month before 2+ GWe of nuclear capacity disappeared (Pickering)
3/4
... and this in the month before 2+ GWe of nuclear capacity disappeared (Pickering)
3/4
October 1, 2026 at 3:44 PM
appending a previous monthly generator output data set... record levels of fossil fuels on the IESO (for Sept.)
... and this in the month before 2+ GWe of nuclear capacity disappeared (Pickering)
3/4
... and this in the month before 2+ GWe of nuclear capacity disappeared (Pickering)
3/4
Estimating the composition of exported supply shows record levels (for Sept.) going back to the beginning of my hourly data set in 2008.
Whereas surplus based/trivial-emission supply, and Quebec wheel-through trade, dominated 2014-2022, recent exports are mostly gas
2/4
Whereas surplus based/trivial-emission supply, and Quebec wheel-through trade, dominated 2014-2022, recent exports are mostly gas
2/4
October 1, 2026 at 3:44 PM
Estimating the composition of exported supply shows record levels (for Sept.) going back to the beginning of my hourly data set in 2008.
Whereas surplus based/trivial-emission supply, and Quebec wheel-through trade, dominated 2014-2022, recent exports are mostly gas
2/4
Whereas surplus based/trivial-emission supply, and Quebec wheel-through trade, dominated 2014-2022, recent exports are mostly gas
2/4
first look/estimates of ON monthly electricity for September.
IESO-controlled grid (ICG):
increased output from hydro and wind offset demand growth, but gas still jumps to allow for increase in net exports
Market rate essentially unchanged
...
1/4
IESO-controlled grid (ICG):
increased output from hydro and wind offset demand growth, but gas still jumps to allow for increase in net exports
Market rate essentially unchanged
...
1/4
October 1, 2026 at 3:44 PM
first look/estimates of ON monthly electricity for September.
IESO-controlled grid (ICG):
increased output from hydro and wind offset demand growth, but gas still jumps to allow for increase in net exports
Market rate essentially unchanged
...
1/4
IESO-controlled grid (ICG):
increased output from hydro and wind offset demand growth, but gas still jumps to allow for increase in net exports
Market rate essentially unchanged
...
1/4
This morning Pickering NGS unit 8 was removed from service - pending a multi-year refurbishment.
EFPH ~272,000
Like unit 7 (removed yesterday), unit 8's highest output year was 2025 -both's last full year of service.
Only Bruce B's reactors performed more hours pre-refurb
EFPH ~272,000
Like unit 7 (removed yesterday), unit 8's highest output year was 2025 -both's last full year of service.
Only Bruce B's reactors performed more hours pre-refurb
September 29, 2026 at 2:34 PM
This morning Pickering NGS unit 8 was removed from service - pending a multi-year refurbishment.
EFPH ~272,000
Like unit 7 (removed yesterday), unit 8's highest output year was 2025 -both's last full year of service.
Only Bruce B's reactors performed more hours pre-refurb
EFPH ~272,000
Like unit 7 (removed yesterday), unit 8's highest output year was 2025 -both's last full year of service.
Only Bruce B's reactors performed more hours pre-refurb
Last week it was unit 5: today we say "so long - for now", to reactor #7 at the Pickering NGS.
I estimate the same 289,000 EFPH for both reactors - pre-refurb.
image is taken from the final report of Ontario Hydro - showing the devaluation of the units entering restructuring.
I estimate the same 289,000 EFPH for both reactors - pre-refurb.
image is taken from the final report of Ontario Hydro - showing the devaluation of the units entering restructuring.
September 28, 2026 at 5:29 PM
Last week it was unit 5: today we say "so long - for now", to reactor #7 at the Pickering NGS.
I estimate the same 289,000 EFPH for both reactors - pre-refurb.
image is taken from the final report of Ontario Hydro - showing the devaluation of the units entering restructuring.
I estimate the same 289,000 EFPH for both reactors - pre-refurb.
image is taken from the final report of Ontario Hydro - showing the devaluation of the units entering restructuring.
My weekly ON electricity reporting.
highest $/MWh since May, on highest wind+solar supply since May, and increased nuclear.
ON demand down 200 GWh; more than cancelled out by net exports up 300 GWh.
rare down week for gas - most of which ran for export (QC main intertie)
highest $/MWh since May, on highest wind+solar supply since May, and increased nuclear.
ON demand down 200 GWh; more than cancelled out by net exports up 300 GWh.
rare down week for gas - most of which ran for export (QC main intertie)
September 28, 2026 at 2:46 PM
My weekly ON electricity reporting.
highest $/MWh since May, on highest wind+solar supply since May, and increased nuclear.
ON demand down 200 GWh; more than cancelled out by net exports up 300 GWh.
rare down week for gas - most of which ran for export (QC main intertie)
highest $/MWh since May, on highest wind+solar supply since May, and increased nuclear.
ON demand down 200 GWh; more than cancelled out by net exports up 300 GWh.
rare down week for gas - most of which ran for export (QC main intertie)
Ontario released its 2025-26 Public Accounts.
I've tracked the claimed subsidies for electricity from past reports - and it's a record $6.9 billion.
Some will point to that as a significant share of the $13B deficit.
with sector asset Δ, I calculate a net sector subsidy <$1B
I've tracked the claimed subsidies for electricity from past reports - and it's a record $6.9 billion.
Some will point to that as a significant share of the $13B deficit.
with sector asset Δ, I calculate a net sector subsidy <$1B
September 24, 2026 at 10:43 PM
Ontario released its 2025-26 Public Accounts.
I've tracked the claimed subsidies for electricity from past reports - and it's a record $6.9 billion.
Some will point to that as a significant share of the $13B deficit.
with sector asset Δ, I calculate a net sector subsidy <$1B
I've tracked the claimed subsidies for electricity from past reports - and it's a record $6.9 billion.
Some will point to that as a significant share of the $13B deficit.
with sector asset Δ, I calculate a net sector subsidy <$1B
The past week in ON electricity (my estimates):
big weeks for hydro and wind didn't stop the growth fueled by natural gas as OPG continued to depress nuclear output, demand remained high(ish), and exports surged.
big weeks for hydro and wind didn't stop the growth fueled by natural gas as OPG continued to depress nuclear output, demand remained high(ish), and exports surged.
September 14, 2026 at 3:18 PM
The past week in ON electricity (my estimates):
big weeks for hydro and wind didn't stop the growth fueled by natural gas as OPG continued to depress nuclear output, demand remained high(ish), and exports surged.
big weeks for hydro and wind didn't stop the growth fueled by natural gas as OPG continued to depress nuclear output, demand remained high(ish), and exports surged.
natural gas fueled a record monthly amount of generation in August.
My estimate should be ~$100 million too high for gas - but the IESO has been finding ways to avoid ratepayers benefiting from the combination of higher DA-OZP and clawbacks on NRR contracts
2/2
My estimate should be ~$100 million too high for gas - but the IESO has been finding ways to avoid ratepayers benefiting from the combination of higher DA-OZP and clawbacks on NRR contracts
2/2
September 1, 2026 at 4:27 PM
natural gas fueled a record monthly amount of generation in August.
My estimate should be ~$100 million too high for gas - but the IESO has been finding ways to avoid ratepayers benefiting from the combination of higher DA-OZP and clawbacks on NRR contracts
2/2
My estimate should be ~$100 million too high for gas - but the IESO has been finding ways to avoid ratepayers benefiting from the combination of higher DA-OZP and clawbacks on NRR contracts
2/2
Ontario electricity August 2026 -estimates:
Demand up ~1.8%, but over 1/3rd of that could be manufactured by increased use of storage - not actual consumption.
little change to Aug'25 in export and market rates.
trivial emission down (nuke, wind, solar, hydro)
gas up and...
1/2
Demand up ~1.8%, but over 1/3rd of that could be manufactured by increased use of storage - not actual consumption.
little change to Aug'25 in export and market rates.
trivial emission down (nuke, wind, solar, hydro)
gas up and...
1/2
September 1, 2026 at 4:27 PM
Ontario electricity August 2026 -estimates:
Demand up ~1.8%, but over 1/3rd of that could be manufactured by increased use of storage - not actual consumption.
little change to Aug'25 in export and market rates.
trivial emission down (nuke, wind, solar, hydro)
gas up and...
1/2
Demand up ~1.8%, but over 1/3rd of that could be manufactured by increased use of storage - not actual consumption.
little change to Aug'25 in export and market rates.
trivial emission down (nuke, wind, solar, hydro)
gas up and...
1/2
IESO breakdown of global adjustment costs updated with July.
~$20M < my estimates
1. OPG +$30M
2. Bruce +$40M
3. Conservation +$11M
4. Non-Hydro Renewables Funding: +$11M
5. Other (incl. storage) +$10M
Gas -$136M (this approximates how much above fuel cost DAOZP recovered)
1/2
~$20M < my estimates
1. OPG +$30M
2. Bruce +$40M
3. Conservation +$11M
4. Non-Hydro Renewables Funding: +$11M
5. Other (incl. storage) +$10M
Gas -$136M (this approximates how much above fuel cost DAOZP recovered)
1/2
August 28, 2026 at 11:32 PM
IESO breakdown of global adjustment costs updated with July.
~$20M < my estimates
1. OPG +$30M
2. Bruce +$40M
3. Conservation +$11M
4. Non-Hydro Renewables Funding: +$11M
5. Other (incl. storage) +$10M
Gas -$136M (this approximates how much above fuel cost DAOZP recovered)
1/2
~$20M < my estimates
1. OPG +$30M
2. Bruce +$40M
3. Conservation +$11M
4. Non-Hydro Renewables Funding: +$11M
5. Other (incl. storage) +$10M
Gas -$136M (this approximates how much above fuel cost DAOZP recovered)
1/2
Good news for Ontario nuclear supporters: the CNSC has agree to a ~3% increase in Bruce Power's reactors.
This will likely increase capacity at the site by ~200 MW, about half the increase needed to get to the 7 GWe Bruce is working to achieve
This will likely increase capacity at the site by ~200 MW, about half the increase needed to get to the 7 GWe Bruce is working to achieve
August 24, 2026 at 6:08 PM
Good news for Ontario nuclear supporters: the CNSC has agree to a ~3% increase in Bruce Power's reactors.
This will likely increase capacity at the site by ~200 MW, about half the increase needed to get to the 7 GWe Bruce is working to achieve
This will likely increase capacity at the site by ~200 MW, about half the increase needed to get to the 7 GWe Bruce is working to achieve
ON electricity weekly notes:
another week of declining trivial-emission generation (comp to ly), on higher demand and pricing.
another week of declining trivial-emission generation (comp to ly), on higher demand and pricing.
August 24, 2026 at 2:56 PM
ON electricity weekly notes:
another week of declining trivial-emission generation (comp to ly), on higher demand and pricing.
another week of declining trivial-emission generation (comp to ly), on higher demand and pricing.
Ontario Power Generation needs a reckoning
Three of OPG’s four refurbished nuclear reactors are currently inoperable
refurbed reactor teething pains, or far deeper problems?
-reliability concerns
-comms absent
-OEB rate-setting absurdity
-gov't financial shenanigans
1/2
Three of OPG’s four refurbished nuclear reactors are currently inoperable
refurbed reactor teething pains, or far deeper problems?
-reliability concerns
-comms absent
-OEB rate-setting absurdity
-gov't financial shenanigans
1/2
August 20, 2026 at 12:00 PM
Ontario Power Generation needs a reckoning
Three of OPG’s four refurbished nuclear reactors are currently inoperable
refurbed reactor teething pains, or far deeper problems?
-reliability concerns
-comms absent
-OEB rate-setting absurdity
-gov't financial shenanigans
1/2
Three of OPG’s four refurbished nuclear reactors are currently inoperable
refurbed reactor teething pains, or far deeper problems?
-reliability concerns
-comms absent
-OEB rate-setting absurdity
-gov't financial shenanigans
1/2
trends in ON electricity pricing.
Another graphic inspired by the increasingly -lengthy, perhaps unplanned, reactor outages at Darlington.
Ontario announcement of the refurbishment early in 2026 claimed post-refurbishment cost of $72-$81/MWh
(not based on 1 of 4 units operating)
Another graphic inspired by the increasingly -lengthy, perhaps unplanned, reactor outages at Darlington.
Ontario announcement of the refurbishment early in 2026 claimed post-refurbishment cost of $72-$81/MWh
(not based on 1 of 4 units operating)
August 18, 2026 at 12:26 PM
trends in ON electricity pricing.
Another graphic inspired by the increasingly -lengthy, perhaps unplanned, reactor outages at Darlington.
Ontario announcement of the refurbishment early in 2026 claimed post-refurbishment cost of $72-$81/MWh
(not based on 1 of 4 units operating)
Another graphic inspired by the increasingly -lengthy, perhaps unplanned, reactor outages at Darlington.
Ontario announcement of the refurbishment early in 2026 claimed post-refurbishment cost of $72-$81/MWh
(not based on 1 of 4 units operating)
Here's why I am triggered by the poor performance at Darlington NGS this year: publicly-owned nuclear power in Ontario has been in the situation where prices were rising as performance was deteriorating.
The combination is not sustainable - maybe not even for 1 election cycle
The combination is not sustainable - maybe not even for 1 election cycle
August 15, 2026 at 1:46 PM
Here's why I am triggered by the poor performance at Darlington NGS this year: publicly-owned nuclear power in Ontario has been in the situation where prices were rising as performance was deteriorating.
The combination is not sustainable - maybe not even for 1 election cycle
The combination is not sustainable - maybe not even for 1 election cycle
Since a March 12th refurb completion Darlington NGS has had all 4 units producing power for only 18 days. Unit 4, the final unit to return from the lengthy life-extension, has operated on only half of the days since its ahead-of-schedule and under-budget celebration.
August 14, 2026 at 3:45 PM
Since a March 12th refurb completion Darlington NGS has had all 4 units producing power for only 18 days. Unit 4, the final unit to return from the lengthy life-extension, has operated on only half of the days since its ahead-of-schedule and under-budget celebration.
OPG released their 2026 Q2 financial results today.
Capital expenditures on nuclear projects year-to-date approach $2.5 billion.
For that spending one might assume more than 1 of 4 refurbished reactors at Darlington to be operating this August.
Nope :(
Capital expenditures on nuclear projects year-to-date approach $2.5 billion.
For that spending one might assume more than 1 of 4 refurbished reactors at Darlington to be operating this August.
Nope :(
August 13, 2026 at 8:53 PM
OPG released their 2026 Q2 financial results today.
Capital expenditures on nuclear projects year-to-date approach $2.5 billion.
For that spending one might assume more than 1 of 4 refurbished reactors at Darlington to be operating this August.
Nope :(
Capital expenditures on nuclear projects year-to-date approach $2.5 billion.
For that spending one might assume more than 1 of 4 refurbished reactors at Darlington to be operating this August.
Nope :(
My ON electricity reporting/estimates for week 32:
natural gas fueled supply rises again, despite a down-demand week.
All trivial-emission types saw lower output, with the exception of biomass - nuclear led the way down (on OPG's unplanned outages).
app.powerbi.com/view...
natural gas fueled supply rises again, despite a down-demand week.
All trivial-emission types saw lower output, with the exception of biomass - nuclear led the way down (on OPG's unplanned outages).
app.powerbi.com/view...
August 10, 2026 at 3:06 PM
My ON electricity reporting/estimates for week 32:
natural gas fueled supply rises again, despite a down-demand week.
All trivial-emission types saw lower output, with the exception of biomass - nuclear led the way down (on OPG's unplanned outages).
app.powerbi.com/view...
natural gas fueled supply rises again, despite a down-demand week.
All trivial-emission types saw lower output, with the exception of biomass - nuclear led the way down (on OPG's unplanned outages).
app.powerbi.com/view...
I updated my reporting for the AESO (Alberta) system through July.
One quick graphic is the share of supply with the "value factor" (gen type avg pool price value:avg for all gen types)
through 7 months avg MWh from wind dropped below 1/2 the overall avg.
One quick graphic is the share of supply with the "value factor" (gen type avg pool price value:avg for all gen types)
through 7 months avg MWh from wind dropped below 1/2 the overall avg.
August 9, 2026 at 6:48 PM
I updated my reporting for the AESO (Alberta) system through July.
One quick graphic is the share of supply with the "value factor" (gen type avg pool price value:avg for all gen types)
through 7 months avg MWh from wind dropped below 1/2 the overall avg.
One quick graphic is the share of supply with the "value factor" (gen type avg pool price value:avg for all gen types)
through 7 months avg MWh from wind dropped below 1/2 the overall avg.
New post: On terrific new visualizations for electricity generation (and transmission) globally - and base data issues glossed over in the presentations.
open.substack.com/pu...
open.substack.com/pu...
July 31, 2026 at 7:17 PM
New post: On terrific new visualizations for electricity generation (and transmission) globally - and base data issues glossed over in the presentations.
open.substack.com/pu...
open.substack.com/pu...
TC Energy reported today, and scanning the results for Bruce Power I'm feeling they're joining OPG in damaging the pro-nuclear story - and I ought to have noticed how earlier than this.
Hoping for some pushback to put me in my place on this thread...
1/5
Hoping for some pushback to put me in my place on this thread...
1/5
July 30, 2026 at 5:13 PM
TC Energy reported today, and scanning the results for Bruce Power I'm feeling they're joining OPG in damaging the pro-nuclear story - and I ought to have noticed how earlier than this.
Hoping for some pushback to put me in my place on this thread...
1/5
Hoping for some pushback to put me in my place on this thread...
1/5
Ontario's electricity system operator released the June global adjustment (GA) figures, so a half year pricing review. The changes to commodity rates (GA plus relevant market average):
Class A: +13% increase
Class B: +2% increase
Regulated Price Plan (RPP): +29%
1/6
Class A: +13% increase
Class B: +2% increase
Regulated Price Plan (RPP): +29%
1/6
July 16, 2026 at 8:30 PM
Ontario's electricity system operator released the June global adjustment (GA) figures, so a half year pricing review. The changes to commodity rates (GA plus relevant market average):
Class A: +13% increase
Class B: +2% increase
Regulated Price Plan (RPP): +29%
1/6
Class A: +13% increase
Class B: +2% increase
Regulated Price Plan (RPP): +29%
1/6