Driving energy demand back 30 years

CORRECTED VERSION - 3.54PM, 8 March 2012. For correction see bottom.

Last week I attended a presentation looking at just how much we could reduce household energy consumption within 10 years without loss of comfort or amenity just by using technology already readily available. 

The results were striking and worthy of entry to Climate Spectator's charts of the week. 

In findings that should send chills down the spines of energy suppliers, co-author Lloyd Harrington outlined that it was technically feasible to cut household energy consumption (both gas and electricity) in half compared to a business as usual path within 10 years. This would mean energy consumption would be brought down to levels that prevailed when Back to the Future was at the cinema.

For those who've never heard of Lloyd Harrington, he is like a walking, talking encyclopaedia on the energy consumption of electric and gas appliances and equipment.  He can cite passages from arcane technical standards governing everything from televisions to refrigerators to light bulbs. Then he'll proceed to tell you how some Asian appliance manufacturer managed to game the test procedure for refrigerators through some clever computer software. 

I've seen him in Australian Standards meetings even manage to out-argue appliance manufacturers with superior understanding of the technical characteristics of their own products. 

Over the years he has steadily built-up an incredibly detailed computer model of each of the different items that influence energy consumption in Australian households down to the level of individual appliances. He has constructed this using in-house surveys, appliance sales data, and cross checks against energy consumption data from government and utilities.

So, in other words, people should think twice before dismissing this analysis as the product of some starry-eyed greenie.

According to Harrington, the chart below illustrates Australia's historic and current path for residential energy consumption without further government policy.

Australian household energy consumption by fuel-function type 1986 to 2020

Source: Energy Efficient Strategies and Beyond Zero Emissions

Interestingly, it illustrates that Australian household electricity consumption is likely to have already peaked even without further government energy efficiency interventions, and excluding the impact of solar PV. However, gas use, mainly for heating purposes, continues to grow. By the way, the large chunk of energy associated with wood is mainly a function of its high levels of inefficiency rather than being highly prevalent across Australian homes.

Lloyd Harrington and his co-researchers then modelled a range of options for how we might upgrade efficiency and contain gas consumption including the scenario illustrated below which aimed for a rapid phase-out of gas.

This research was undertaken for Beyond Zero Emissions as part of their Buildings Plan and complements its push for generating electricity purely from renewables – hence the desire to phase out gas in favour of electricity.

Australian household energy consumption under a rapid phase-out of gas and adoption of best available efficiency electrical appliances on market today

Source: Energy Efficient Strategies and Beyond Zero Emissions

Under this scenario the stand-out feature is obviously the disappearance of gas for heating, cooking and water heating purposes. Instead, highly efficient reverse cycle air conditioners are used for heating, induction cook-tops for stoves, and heat-pumps with solar for heating water.

This leads to an increase in the yellow segment of the chart covering electric heating and cooking relative to the BAU chart above. But it is a surprisingly small increase, and overall electricity use is 12 per cent lower than under the BAU case.

The reason they've managed to keep electricity use low in spite of phasing out gas is because they also upgrade all electrical appliances to the energy efficiency of the best available technology already on the market today. This means there are significant savings for those households already heating their homes with electricity as well as very significant reductions the red section representing generic electrical appliances like televisions and refrigerators.

"Best available technology" may sound impressive, but given underlying technological improvement and the 10-year time period, it may not be all that hard. The other day I went through a JB Hi-Fi and found a large number of 32-inch televisions consume less than 160kWh per annum. When I bought my television there just two years ago you would have found equivalent models were consuming about 200kWh. Even the boring old refrigerator is expected to realise a 30 per cent improvement when Australia matches the US energy efficiency standard, according to Harrington.

Interestingly this scenario did not involve any upgrade to the efficiency of pre-existing homes' thermal shell via say greater insulation or sealing-up of draughts. With such upgrades their research suggests electricity consumption could be further reduced from 182PJ down to 164PJ per year.

Further, as Harrington excitingly explained, this doesn't take into account the possibilities of solar PV to further reduce households' demand for energy. 

Harrington points out that if solar PV were to maintain the sales levels achieved last year then it would shave off a further 45 petajoules, or about a fifth of household energy demand.

Of course this won't happen without government recovering some of its lost enthusiasm for energy efficiency.  But it looks like Beyond Zero Emissions' forthcoming Buildings Plan will again force us all to think far harder about what might be possible, instead of taking the easy path of just saying it can't be done because it hasn't been tried before.

CORRECTION

An earlier version of this article stated that the second chart reflected a scenario in which there were moderate retrofit upgrades to the thermal shell efficiency of existing homes. In fact these results represent a scenario in which no changes are made to the thermal shell efficiency of existing homes.