Scott Luft
@scottluft.bsky.social
Data Manager, Communicator, Advocate for consumers, and nuclear power.
Ontario electricity reporting of IESO-controlled grid (Tx) data now through week 51 (ended Dec. 21, 2025)
demand, and market pricing, still higher than since 2008, but moderating along with temps.
high wind and increased gas compensated for lower hydro and nuclear
demand, and market pricing, still higher than since 2008, but moderating along with temps.
high wind and increased gas compensated for lower hydro and nuclear
December 22, 2025 at 2:18 PM
Ontario electricity reporting of IESO-controlled grid (Tx) data now through week 51 (ended Dec. 21, 2025)
demand, and market pricing, still higher than since 2008, but moderating along with temps.
high wind and increased gas compensated for lower hydro and nuclear
demand, and market pricing, still higher than since 2008, but moderating along with temps.
high wind and increased gas compensated for lower hydro and nuclear
the bad news is Enbridge's latest reporting of natural gas storage levels shows another big drawdown on a level already well below what is typical for the time of year.
Expect pricing to rise significantly if temperatures drop significantly.
2/2
Expect pricing to rise significantly if temperatures drop significantly.
2/2
December 18, 2025 at 2:30 PM
the bad news is Enbridge's latest reporting of natural gas storage levels shows another big drawdown on a level already well below what is typical for the time of year.
Expect pricing to rise significantly if temperatures drop significantly.
2/2
Expect pricing to rise significantly if temperatures drop significantly.
2/2
good news and bad news for Ontario electricity wholesale rates.
Some good news is a warmer day with good wind had the rates in the day-ahead market well below they $100+/MWh pricing we've been seeing for weeks.
Natural gas pricing at Enbridge's Dawn hub has declined.
1/2
Some good news is a warmer day with good wind had the rates in the day-ahead market well below they $100+/MWh pricing we've been seeing for weeks.
Natural gas pricing at Enbridge's Dawn hub has declined.
1/2
December 18, 2025 at 2:30 PM
good news and bad news for Ontario electricity wholesale rates.
Some good news is a warmer day with good wind had the rates in the day-ahead market well below they $100+/MWh pricing we've been seeing for weeks.
Natural gas pricing at Enbridge's Dawn hub has declined.
1/2
Some good news is a warmer day with good wind had the rates in the day-ahead market well below they $100+/MWh pricing we've been seeing for weeks.
Natural gas pricing at Enbridge's Dawn hub has declined.
1/2
GA=Global Adjustment
defined as the difference between the committed cost of supply and the value recovered in sales on the market. A monthly charge since 2008, I have it trending to be a credit each of these past 2 weeks.
This does remarkable things to consumer rates
4/5
defined as the difference between the committed cost of supply and the value recovered in sales on the market. A monthly charge since 2008, I have it trending to be a credit each of these past 2 weeks.
This does remarkable things to consumer rates
4/5
December 15, 2025 at 4:19 PM
GA=Global Adjustment
defined as the difference between the committed cost of supply and the value recovered in sales on the market. A monthly charge since 2008, I have it trending to be a credit each of these past 2 weeks.
This does remarkable things to consumer rates
4/5
defined as the difference between the committed cost of supply and the value recovered in sales on the market. A monthly charge since 2008, I have it trending to be a credit each of these past 2 weeks.
This does remarkable things to consumer rates
4/5
moving to reporting inclusive of estimates on distributed generation, curtailment, and costing...
there is an increase in supply costs due to higher spending on natural gas-fueled generators, but much of that increase is offset by export sales - and more likely to reduce GA
3/5
there is an increase in supply costs due to higher spending on natural gas-fueled generators, but much of that increase is offset by export sales - and more likely to reduce GA
3/5
December 15, 2025 at 4:19 PM
moving to reporting inclusive of estimates on distributed generation, curtailment, and costing...
there is an increase in supply costs due to higher spending on natural gas-fueled generators, but much of that increase is offset by export sales - and more likely to reduce GA
3/5
there is an increase in supply costs due to higher spending on natural gas-fueled generators, but much of that increase is offset by export sales - and more likely to reduce GA
3/5
My Ontario Electricity reporting/estimates now updated through ISO week 50 2025.
Average day-ahead Ontario zonal price was ~$140/MWh - up nearly $100/MWh over comp wk ly.
I have this as an IESO record weekly average rate when weighted to ON demand [treating DA-OZP as HOEP]
1/5
Average day-ahead Ontario zonal price was ~$140/MWh - up nearly $100/MWh over comp wk ly.
I have this as an IESO record weekly average rate when weighted to ON demand [treating DA-OZP as HOEP]
1/5
December 15, 2025 at 4:18 PM
My Ontario Electricity reporting/estimates now updated through ISO week 50 2025.
Average day-ahead Ontario zonal price was ~$140/MWh - up nearly $100/MWh over comp wk ly.
I have this as an IESO record weekly average rate when weighted to ON demand [treating DA-OZP as HOEP]
1/5
Average day-ahead Ontario zonal price was ~$140/MWh - up nearly $100/MWh over comp wk ly.
I have this as an IESO record weekly average rate when weighted to ON demand [treating DA-OZP as HOEP]
1/5
Large market rate (need to update naming for 2025 from HOEP to Day-ahead ON zone rate) = less cost transfer to class B (small) consumers from exporters and large "Class A" users (which include industry).
4/5
4/5
November 24, 2025 at 4:32 PM
Large market rate (need to update naming for 2025 from HOEP to Day-ahead ON zone rate) = less cost transfer to class B (small) consumers from exporters and large "Class A" users (which include industry).
4/5
4/5
here's a format I've used for a while to summarize generation, cost, and (hugely diminished) curtailment.
While costs are up a little, as is demand, different consumer classes will see much different rate impacts (even if OEB delays them for a year with bad rate setting)
3/5
While costs are up a little, as is demand, different consumer classes will see much different rate impacts (even if OEB delays them for a year with bad rate setting)
3/5
November 24, 2025 at 4:32 PM
here's a format I've used for a while to summarize generation, cost, and (hugely diminished) curtailment.
While costs are up a little, as is demand, different consumer classes will see much different rate impacts (even if OEB delays them for a year with bad rate setting)
3/5
While costs are up a little, as is demand, different consumer classes will see much different rate impacts (even if OEB delays them for a year with bad rate setting)
3/5
Imports notably rose, while exports fell (from the comp wk in 2024).
My page estimating what drove exports shows almost all the imports were wheeled through Ontario - which isn't strange.
most imports came from MI, and majority of exports were through interties with Quebec.
2/5
My page estimating what drove exports shows almost all the imports were wheeled through Ontario - which isn't strange.
most imports came from MI, and majority of exports were through interties with Quebec.
2/5
November 24, 2025 at 4:32 PM
Imports notably rose, while exports fell (from the comp wk in 2024).
My page estimating what drove exports shows almost all the imports were wheeled through Ontario - which isn't strange.
most imports came from MI, and majority of exports were through interties with Quebec.
2/5
My page estimating what drove exports shows almost all the imports were wheeled through Ontario - which isn't strange.
most imports came from MI, and majority of exports were through interties with Quebec.
2/5
My weekly Ontario electricity reporting/estimates, and commentary.
The basic IESO data shows steep declines in output from nuclear (-273 GWh), hydro (-124 GWh) and wind (-83 GWh), all while provincial demand on the IESO grid rose ~ 170 GWh.
Gas fueled 363 GWh more supply
1/5
The basic IESO data shows steep declines in output from nuclear (-273 GWh), hydro (-124 GWh) and wind (-83 GWh), all while provincial demand on the IESO grid rose ~ 170 GWh.
Gas fueled 363 GWh more supply
1/5
November 24, 2025 at 4:32 PM
My weekly Ontario electricity reporting/estimates, and commentary.
The basic IESO data shows steep declines in output from nuclear (-273 GWh), hydro (-124 GWh) and wind (-83 GWh), all while provincial demand on the IESO grid rose ~ 170 GWh.
Gas fueled 363 GWh more supply
1/5
The basic IESO data shows steep declines in output from nuclear (-273 GWh), hydro (-124 GWh) and wind (-83 GWh), all while provincial demand on the IESO grid rose ~ 170 GWh.
Gas fueled 363 GWh more supply
1/5
demand now is similar to what it was in 1989: generation higher.
Another graphic shows only the annual change to 1989. I focus on the sharp increase in fossil(gas) since 2021 headed back to the level of fossil(coal) in 1989, but note what's driving that...
2/3
Another graphic shows only the annual change to 1989. I focus on the sharp increase in fossil(gas) since 2021 headed back to the level of fossil(coal) in 1989, but note what's driving that...
2/3
November 21, 2025 at 4:36 PM
demand now is similar to what it was in 1989: generation higher.
Another graphic shows only the annual change to 1989. I focus on the sharp increase in fossil(gas) since 2021 headed back to the level of fossil(coal) in 1989, but note what's driving that...
2/3
Another graphic shows only the annual change to 1989. I focus on the sharp increase in fossil(gas) since 2021 headed back to the level of fossil(coal) in 1989, but note what's driving that...
2/3
A long-term illustration of annual generation, and demand, statistics for Ontario's electricity system can provide context to frame opinions stated as facts in media both old and new.
I've updated this graphic with 2024 data.
1/3
I've updated this graphic with 2024 data.
1/3
November 21, 2025 at 4:36 PM
A long-term illustration of annual generation, and demand, statistics for Ontario's electricity system can provide context to frame opinions stated as facts in media both old and new.
I've updated this graphic with 2024 data.
1/3
I've updated this graphic with 2024 data.
1/3
Ontario’s energy regulator is been making nuclear expensive:
OPG roars to record profits on its nuclear while consumer pricing soars.
open.substack.com/pu...
2/2
OPG roars to record profits on its nuclear while consumer pricing soars.
open.substack.com/pu...
2/2
November 16, 2025 at 5:36 PM
Ontario’s energy regulator is been making nuclear expensive:
OPG roars to record profits on its nuclear while consumer pricing soars.
open.substack.com/pu...
2/2
OPG roars to record profits on its nuclear while consumer pricing soars.
open.substack.com/pu...
2/2
My new article argues that to the extent nuclear contributes to the OEB's extraordinary November rate hike, it is mostly due to the OEB's poor management of regulating rates for OPG's nuclear assets.
Rates for nuclear next year are based on far too little production forecast
1/2
Rates for nuclear next year are based on far too little production forecast
1/2
November 16, 2025 at 5:36 PM
My new article argues that to the extent nuclear contributes to the OEB's extraordinary November rate hike, it is mostly due to the OEB's poor management of regulating rates for OPG's nuclear assets.
Rates for nuclear next year are based on far too little production forecast
1/2
Rates for nuclear next year are based on far too little production forecast
1/2
Adding in estimates for distributed generators, curtailment and costs shows increased revenue on exported supply largely cancelling out the increased cost from gas generation
this reporting at app.powerbi.com/view?r=eyJrI...
3/3
this reporting at app.powerbi.com/view?r=eyJrI...
3/3
November 10, 2025 at 3:49 PM
Adding in estimates for distributed generators, curtailment and costs shows increased revenue on exported supply largely cancelling out the increased cost from gas generation
this reporting at app.powerbi.com/view?r=eyJrI...
3/3
this reporting at app.powerbi.com/view?r=eyJrI...
3/3
Notes from my Ontario electricity reporting/estimates now through week 45.
compared to last week supply from nuclear and hydro was down ~190 GWh while demand rose 190 GWh and so supply fueled by natural gas climbed 400 GWh.
Market rate a record high for week 45's
1/
compared to last week supply from nuclear and hydro was down ~190 GWh while demand rose 190 GWh and so supply fueled by natural gas climbed 400 GWh.
Market rate a record high for week 45's
1/
November 10, 2025 at 3:49 PM
Notes from my Ontario electricity reporting/estimates now through week 45.
compared to last week supply from nuclear and hydro was down ~190 GWh while demand rose 190 GWh and so supply fueled by natural gas climbed 400 GWh.
Market rate a record high for week 45's
1/
compared to last week supply from nuclear and hydro was down ~190 GWh while demand rose 190 GWh and so supply fueled by natural gas climbed 400 GWh.
Market rate a record high for week 45's
1/
the defining trend of the past few years in Ontario electricity exports, and imports, is the nearing 12 TWh/year change with Quebec.
Michigan is also notable as it is not pulling as much from Ontario as it did in the past decade and a half.
Michigan is also notable as it is not pulling as much from Ontario as it did in the past decade and a half.
November 7, 2025 at 10:05 AM
the defining trend of the past few years in Ontario electricity exports, and imports, is the nearing 12 TWh/year change with Quebec.
Michigan is also notable as it is not pulling as much from Ontario as it did in the past decade and a half.
Michigan is also notable as it is not pulling as much from Ontario as it did in the past decade and a half.
Conversely, it is the least expensive week in a while for exporters, and large, Class A, consumers.
That's the impact of the global adjustment mechanisms in distributing costs not recovered through market pricing unevenly across consumer groups.
4/4
That's the impact of the global adjustment mechanisms in distributing costs not recovered through market pricing unevenly across consumer groups.
4/4
April 21, 2025 at 3:08 PM
Conversely, it is the least expensive week in a while for exporters, and large, Class A, consumers.
That's the impact of the global adjustment mechanisms in distributing costs not recovered through market pricing unevenly across consumer groups.
4/4
That's the impact of the global adjustment mechanisms in distributing costs not recovered through market pricing unevenly across consumer groups.
4/4
Adding estimates on distributed generation, curtailment, and costs, I show the past week as the 11th most expensive for small, Class B, consumers.
[prior to government subsidy of non-hydro renewable suppliers]
ON makes spring shoulder season expensive
3/4
[prior to government subsidy of non-hydro renewable suppliers]
ON makes spring shoulder season expensive
3/4
April 21, 2025 at 3:08 PM
Adding estimates on distributed generation, curtailment, and costs, I show the past week as the 11th most expensive for small, Class B, consumers.
[prior to government subsidy of non-hydro renewable suppliers]
ON makes spring shoulder season expensive
3/4
[prior to government subsidy of non-hydro renewable suppliers]
ON makes spring shoulder season expensive
3/4
Exports were driven by surplus baseload generation - in IESO parlance. That's an excess of committed supply from nuclear, hydro, wind and solar.
That's unlike the exports of the cold winter, which were largely cheap generation from natural gas
2/4
That's unlike the exports of the cold winter, which were largely cheap generation from natural gas
2/4
April 21, 2025 at 3:08 PM
Exports were driven by surplus baseload generation - in IESO parlance. That's an excess of committed supply from nuclear, hydro, wind and solar.
That's unlike the exports of the cold winter, which were largely cheap generation from natural gas
2/4
That's unlike the exports of the cold winter, which were largely cheap generation from natural gas
2/4
My Ontario electricity reporting now updated through week 16.
This is a model for expensive electricity for Ontario households.
rate (HOEP) dropping near 3 cents/kWh while exports surge: for every 5 kWh consumed in the province, 1.1 was sent away for little.
1/4
This is a model for expensive electricity for Ontario households.
rate (HOEP) dropping near 3 cents/kWh while exports surge: for every 5 kWh consumed in the province, 1.1 was sent away for little.
1/4
April 21, 2025 at 3:07 PM
My Ontario electricity reporting now updated through week 16.
This is a model for expensive electricity for Ontario households.
rate (HOEP) dropping near 3 cents/kWh while exports surge: for every 5 kWh consumed in the province, 1.1 was sent away for little.
1/4
This is a model for expensive electricity for Ontario households.
rate (HOEP) dropping near 3 cents/kWh while exports surge: for every 5 kWh consumed in the province, 1.1 was sent away for little.
1/4
"UNAUTHORIZED MOORING OF BOATS IS PROHIBITED
MNR"
...and foolish given the dilapidated condition of the [former?] structure.
MNR"
...and foolish given the dilapidated condition of the [former?] structure.
April 6, 2025 at 1:25 PM
"UNAUTHORIZED MOORING OF BOATS IS PROHIBITED
MNR"
...and foolish given the dilapidated condition of the [former?] structure.
MNR"
...and foolish given the dilapidated condition of the [former?] structure.
so I thought I'd celebrate the day with a rant.
Power went out Saturday night.
Hydro One lied it was expected back at 4 pm Sunday, then 6 pm, then 9 PM last night.
Just for giggles I refreshed the outage map after 9 pm - minutes later it was "reassessing"; then Thurs 9pm
2/6
Power went out Saturday night.
Hydro One lied it was expected back at 4 pm Sunday, then 6 pm, then 9 PM last night.
Just for giggles I refreshed the outage map after 9 pm - minutes later it was "reassessing"; then Thurs 9pm
2/6
April 1, 2025 at 2:33 PM
so I thought I'd celebrate the day with a rant.
Power went out Saturday night.
Hydro One lied it was expected back at 4 pm Sunday, then 6 pm, then 9 PM last night.
Just for giggles I refreshed the outage map after 9 pm - minutes later it was "reassessing"; then Thurs 9pm
2/6
Power went out Saturday night.
Hydro One lied it was expected back at 4 pm Sunday, then 6 pm, then 9 PM last night.
Just for giggles I refreshed the outage map after 9 pm - minutes later it was "reassessing"; then Thurs 9pm
2/6
oops - here's the capital spending
March 8, 2025 at 8:04 PM
oops - here's the capital spending
The amount of the overfunded positions in nuclear funds for decommissioning and used fuel, deemed asset of the provinces, increased by over $2.5 billion
2/2
2/2
March 8, 2025 at 7:59 PM
The amount of the overfunded positions in nuclear funds for decommissioning and used fuel, deemed asset of the provinces, increased by over $2.5 billion
2/2
2/2