Chilly winter evenings show demand has declined for various reasons – not just solar PV

I know it’s not exactly the most statistically relevant sample, but it seemed to be the coolest day so far as I rode home early this evening (and cooler than I had remembered prior years to be).

This prompted me to have a look at NEM-Watch when I arrived home to see how far demand had climbed – we see here in this snapshot from 19:30 that the NEM-Wide demand was 28,433MW:

SA price spike on a winter evening when demand climbs with the cold

Looking a little further, I saw that NEM-Wide demand had climbed past 29,000MW over each of the past 3 evenings (highest being 29,678 this evening at 17:55), but has not yet exceeded 30,000MW.  That means that winter demand is still a whopping 4,500MW lower than the all-time record set back in winter 2008.

As I noted back at the start of this presentation relating to the massive prices seen in QLD over summer, the NEM is a complex place.

This means that it is typically the interaction of a number of significant variables that will fully explain most events (in other words, it is rarely a single variable).

This is especially the case when understanding why demand has been declining of late.  A couple years ago we posted this list of contributing factors, and we’ve continued to ponder this phenomenon since that time:

1)  The most obvious potential reason why demand did not even break 30,000MW this evening, is that it’s just not as cold as it was on prior occasions when this did happen (especially back in winter 2008).  We have not had time to look into this, at present, but flag it as a possibility.

2)  Obviously there cannot be an effect of solar PV in winter evenings, as the sun has long since departed for the day.  Hence this leaves us looking for other reasons for a major loss of demand.

3)  One other possible cause is that smaller embedded (non-scheduled) wind farms have netted off the Scheduled Demand figure – but a quick reference to ez2viewAustralia* reveals that there’s not much wind output coming in SA or VIC (indeed, that – and the fact that Northern is not the saviour** today because of a tube leak – are two of the reasons we see the price has spiked to close to the Market Price Cap in the snapshot above).

* ez2view is a “top shelf” ***, and now awarded, higher end dashboard-style view of the market, in the tradition of NEM-Watch, used by a growing number of traders and others with real money at stake.
** with respect to your comments C
*** thanks J

4)  Three reasons that look likely are as follows:

(a)  The change-out of energy-inefficient incandescent bulbs for compact fluorescent (and also halogens for LEDs) will have had a significant impact on the demand at this time of the evening – see here for some useful information.

(b)  The use of more efficient types of space heating (as opposed to the old-style radiant heaters) will also have had some effect;

(c)  The government-sponsored installation of pink batts in rooftops will also have had some effect (though we’re not sure how we could put a number on this).

(d)  Perhaps an increased penetration of solar hot water might have had some effect – though, at least in Queensland, most of the previously installed electric heating would have been on off-peak tariffs.

We will be interested to see how winter continues to play out….


An update on our review of what happened in QLD over summer

We have continued to work on this (yes, it’s taken longer than we would have hoped – because the NEM is a complex place, and because we’ve been striving to deliver a comprehensive review).  We should have this out before too much longer…

To pre-order your copy of this report before it is released (and save 10%), please fax back this order form today.

About the Author

Paul McArdle
One of three founders of Global-Roam back in 2000, Paul has been CEO of the company since that time. As an author on WattClarity, Paul's focus has been to help make the electricity market more understandable.

2 Comments on "Chilly winter evenings show demand has declined for various reasons – not just solar PV"

  1. Barend van der Poll | Tuesday, July 16 2013 at 12:50 pm | Reply

    I agree with your thought process, but the other factor, which you may have considered is cost. I think that a far larger part of the population are being more careful about energy costs. I believe the cost of energy to moms and dads is now becoming a significant part of the household budget and therefore things are being done to keep the costs down.

    We, for example, have dropped our ducted heating system by 1 degree to 19 deg C and on weekends be actually switch it off and just wear more clothes, where we previously left it on for the weekends.

    I am also meeting more and more people who are looking for alternatives. Took a cab to the airport last month and the cabbie told me that using homemade vertical axis wind turbines using 44 gallon drums and old car batteries, he had so far converted his entire shed to an off grid system and was starting to expand into his house.

Leave a comment

Your email address will not be published.