Peak Electricity Load for PEI Yesterday

Prince Edward Island hit a new peak electricity load of 280 megawatts yesterday at 5:00 p.m.: Islanders were collectively using more electricity at that point than ever before in history. 

In fact the load, measured every 15 minutes from 5:00 p.m. all the way to 8:40 p.m. was more than the previous peak of 264.66 MW reached three years ago on January 6, 2015.

Here’s what the load, and the wind energy generation, looked like yesterday:

PEI Electricity Load and Generation on December 27, 2017

The other story told by this chart is that we were well-served by the wind: between 49% and 77% of our electricity needs were met by wind energy generation over the course of the day.

The increased capacity of the submarine cable to New Brunswick, combined with the wind energy, meant that there was no need to fire up local fossil-fuel generators, despite the peak.

If you’d like to drill into the data in more detail, here are all the samples recorded yesterday as a CSV file.


Peter Rukavina's picture
Peter Rukavina on December 28, 2017 - 18:07 Permalink

Today’s peak was 279 MW, which would have been remarkable if we hadn’t had yesterday’s.

As I pointed out in 2013, the PEI Energy Commission report, released in 2012, said:

The cables are now 35 years in service and the province’s peak load exceeds 220 MW . Current projected load growth for Prince Edward Island is 1 .5% to 2% per year which may push the peak load into the 250 MW range by 2018.

It’s clear now, on the cusp of 2018, that they were 30 MW off in their estimate.


Nathan's picture
Nathan on January 9, 2018 - 14:00 Permalink

The more recent "Integrated System Plan 2017" forecast a 2017 peak of 241MW and a 2022 peak of 254MW. Still well below the new 280MW peak.

See "Table 9" on page 21 of

It's worth noting that the required capacity for MECL is the actual peak minus the interruptible load plus 15% reserve.

The "interruptible load" are industrial customers that pay a lower rate for less reliability since they have their own backup generators on site. MECL can shut them off as necessary to reduce load during peak times. The interruptible load is 14MW for 2017 and beyond.

So the new required capacity based on the recent 280MW peak is 306MW. Good thing the new cables under the strait were completed in 2017.