Solar Cities’ insight into the electricity demand fall

Last year I wrote about how the Howard government’s 2004 Solar Cities initiative was, unlike many other Energy White Paper initiatives, actually showing some promising results. Now one of those ‘Solar Cities’ – Central Victoria – has delivered its final evaluation report with some useful insights into how household electricity demand is falling.

The Central Victorian Solar City encompassed a range of regional towns and surrounding farming areas from Swan Hill along the Murray at the north; to Ararat, Ballarat and Bendigo.

One of the main reasons for undertaking the Solar Cities was to test and learn various approaches for reducing energy and greenhouse gas emissions.  By themselves the Solar Cities were too small to make any major difference to Australia’s greenhouse gas emissions.

One of the good things about the Central Victorian Solar City was that they put a bit of effort into establishing a control group of households for whom they did not attempt to assist in reducing their energy consumption.  This gives a good insight into what was happening with overall electricity demand in the Central Victorian Solar City Region as well as the extent to which the Solar City interventions made any real difference.

The chart below, which is our chart of the week, illustrates that reductions in electricity demand were universal across not just those involved in the Solar City, but also the control group. 

Average daily electricity consumption for control and intervention households (kWh)

Graph for Solar Cities’ insight into the electricity demand fall

Source: Central Victoria Solar City Final Report 2012-13

What’s really interesting is that reductions in the control group were actually very large, average electricity consumption reduced from 16kWh per day to a touch above 13kWh. Across an entire year this works out to a reduction of around 1000kWh, similar to the reductions experienced in Energex’s South-East Queensland region.

This is a very big reduction – equivalent in scale to removing a refrigerator and air conditioner from every home. Some level of care is required however, because this data has not been analysed to adjust for any possible weather effects.

Yet even though the control group had quite significant reductions in consumption, the households targeted by the Solar City achieved a further 13 per cent reduction in consumption compared to similar households within the control group.  

The data suggest they were able to pull out electricity consumption equivalent to another refrigerator through a combination of measures including home energy assessments, promoting solar hot water and solar PV, use of in-home displays and housing retrofits. 

The chart below illustrates the extent of reductions in electricity consumption by intervention type. The gross effect indicated in yellow is the actual impact on households’ electricity consumption before and after they implemented the intervention. The net effect is an adjustment factor to assess the role of the Solar City in driving these reductions. 

This is to account for the fact that many of the those in the control group were also installing solar PV and solar hot water and installing insulation etc. even though they hadn’t been targeted by the Solar City group. 

Changes in household electricity consumption by intervention type

Graph for Solar Cities’ insight into the electricity demand fall

Source: Central Victoria Solar City Final Report 2012-13

More from Business Spectator

Comments on this article

Comments Policy

So looking at those figures, why have Governments reduced subsidies for Solar PV and Solar hot water, not to mention Insulation. We should be promoting every way of reducing energy consumption. Only today the World Bank released it's Turn Down the Heat report, further emphasising (if we needed more evidence) of the need to decarbonise our economy quickly. The LNP are looking more and more like dinosaurs in their pathetic policy on Climate change, yet they will be our next Government - really scary.


The Solar Cities Program "sought to identify and explain the barriers to the uptake of energy saving measures for a wide range of electricity consumers". It was not politically motivated and it has identified solar, and solar hot water systems in particular, has having the most potential in reducing electrical consumption.

Unfortunately in Australia this area has become a political battleground which exemplifies how few 'real problems' we have since no-brainer like this, i.e. making greater use of solar and other renewable energy sources, is debated instead of being accepted and implemented as a matter of fact.

Thanks for the article.


Two weeks ago Greg Combet observed that greenhouse gas emissions from power generation had declined by 7% in the year since the introduction of the carbon tax. He attributed this to the carbon tax. In fact there was a 3.4% decline in 2012 and a 1.4% decline in 2011. The decline is an observable trend which predates the carbon tax ie it is in line with the trend in lower electricity consumption generally in the community, as you have shown here. So how much of the 7% decline in CO2 is explained by the carbon tax and how much by the accelerating reduction in demand for electricity caused by other factors? Was Combet just pulling our chain?


Approximately 3 / 4 of energy consumption in Australia (2010 about 3,962 PJ) is by INDUSTRY NOT households. Solar energy accounted for less than 1%.

This raises the question of whether solar subsidisation to households is capable of meaningfully reducing emissions at a cost we can afford.

Between 2007 and 2012 (June quarter) retail electricity prices rose by 72%, (Melbourne 84%) – compared to CPI up 5%. Presumably similar % rises applied to Victorian towns.

Findings from the Environmental Views and Behaviours Survey (2007-2008) showed that people not concerned with Climate Change (78%) had reduced electricity use.

Australians’ are mainly concerned about the rising cost of energy. In 2009 – 2010 Australian households under financial stress with 13% reporting they were unable to pay electricity, gas or telephone bills on time.

Perspective is important.


Apologies CPI up 15% during that period


We live off the grid, wood heater with wetback, solar hot water heater and gas/wood for cooking. Our electricity use is around 3.5k W per day. It's clear that households could cut a fair amount with appropriate strategies but the rent-seeking bureaucracies cannot tolerate that happening because they would have no source of income. One reason industry is favoured by government is that they pay government lots of money, thus justifying multiple positions.

Of course, industry collects the money they pay to government from the rest of us (btw. this gives the lie to business taxes of course). The national accounts don't reveal these facts which serves to conceal the role of rent seekers in diminishing our national and personal wealth.

Australia needs to report on how much is spent on administration, how much on services (like power) and how much on actually delivering services to the people. When that happens, we can have an informed debate about change.


One question raised for me by the graph of Average Daily Electricity Consumption is the timing of involvement with the project against the 'Intervention period'. For the involved householdes, there seems to be a clear decrease in the average reduction 1.5 years before the intervention period. So, were these households signed up to the project at that time and putting off action that they might otherwise have taken. I look forward to the full report, thanks for bringing some of the clear trends up for discussion Tristran.