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Solar’s bite into energy demand – Climate Spectator

Our charts of the week look at how the reduction in electricity demand plays out over the time of day relative to the peak in National Electricity Market demand in 2007-08. Produced by Professor Mike Sandiford of Melbourne University’s Energy Institute, they reveal some interesting patterns.

What these charts show is that in Queensland and South Australia, where the uptake of solar PV per household is twice what it is in Victoria and New South Wales, solar PV has left an indelible mark on electricity demand. Between 7am and 4pm in Queensland and 7am until 5pm in South Australia you can see demand being eaten away by a bit more each year.

SA has always led the country in solar PV uptake and it was the first that started seeing demand drop in line with the rise and setting of the sun. At first the impact was faint, but it became clear in 2011 and then really hit hard in 2012 when the country installed a gigawatt of solar PV. SA’s demand around midday is now 10 per cent lower than it was in 2007-08, yet when the sun is down demand is barely any different to the benchmark year.

 

Source: Professor Mike Sandiford – Melbourne Energy Institute

In Queensland, demand continued to rise in the financial years to June 2009 and June 2010. But then solar installations started to pick up in the Sunshine State. Consistent with the surge in installations over 2012 and up to June 2013, we’ve seen a dive in demand during daylight hours, reaching a reduction of nearly 6 per cent around midday.

Graph for Solar's bite into energy demand

Source: Professor Mike Sandiford – Melbourne Energy Institute

Victoria and NSW demand patterns are illustrated below, which are a bit more complicated.

Both also have a solar signature dip over 7am to 4pm, but less distinct than Queensland and SA, consistent with their lower uptake of solar. But they also have experienced reductions across the board, with the demand stepping down over all time periods. And for NSW in 2012-13 you can see how the time profile of demand barely changed, but was just shifted uniformly down, reflecting the signature of the Kurri Kurri’s smelter shut-down, with its constant baseload demand.

What’s a little puzzling is the sharp dip in Victoria’s demand between midnight and 5am. One theory is that it reflects households abandoning off-peak electric storage water heating. Energy retailers in Victoria have been phasing out the large discount for off-peak water heating. This, in addition with incentives for solar and heat pumps and new home regulations encouraging solar, may have finally spelled the end for energy guzzling electric storage water heaters.

More data is required to be conclusive. But if right, this illustrates what might have been possible if NSW and Queensland governments had co-operated on a national phase-out of electric storage water heaters in these states where they are far more prevalent and a large proportion (40 per cent in south-east QLD) operate during high demand periods (not in off-peak).

Graph for Solar's bite into energy demand

Source: Professor Mike Sandiford – Melbourne Energy Institute

Graph for Solar's bite into energy demand

Source: Professor Mike Sandiford – Melbourne Energy Institute

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