Efficiency is not “embroidery” for renewables and electrification – it’s fundamental

How can energy efficiency compete with batteries and solar?

Answer: It shouldn’t have to compete. It underpins cost-effective and socially beneficial roll-out of batteries, electrification and solar.

As I and my RMIT colleagues showed a couple of years ago, an electric reverse cycle air conditioner in an uninsulated home struggles to provide comfort. It will also have to be much bigger and more expensive to achieve anything like the comfort that a smaller RCAC could deliver in a thermally efficient building.

High efficiency heat pump clothes dryers have much lower peak demand, dry more clothes, avoid condensation and mould, and reduce building air leakage that drives high heating bills. And purchase costs have come down. They should be mandatory in apartments, where condensation and mould are common problems.

The same applies in industry. Optimising process efficiency before using renewable electricity, thermal storage and smart management cuts the cost of transition and offers other benefits such as more consistent product quality, improved working environments and more. The International Energy Agency has been pointing this out for over a decade.

Inefficient building and appliance energy use drives high peak demand and associated fixed charges on energy bills, that we can’t avoid without disconnecting from the grid, as well as risks of power failures. This is a serious problem in extreme winter weather when variable renewable generation may be low and efficiency of heat pumps also falls.

As I showed in a recent Renew Economy article , inefficient use of electricity generates higher emissions than using gas, and for people using grid electricity this will be the situation for some years. 

See: Electrification is not just about getting off gas – efficiency matters, too

An electric car is typically heavier than its internal combustion competitor: it consumes more energy to accelerate and relies on high aerodynamic efficiency to deliver good range at highway speeds. Hilly and windy roads also affect heavier vehicles.

It is the high efficiency of an electric motor and energy recovery when slowing down that make the difference. A reverse cycle air conditioner is four times as efficient has a gas heater. It just happens to use electricity – it could use a gas engine and capture much of this efficiency benefit, though this could have higher capital cost.

Heat pump efficiency declines in cold weather, and ‘icing up’ of poorly designed heat pumps drives ‘need’ for bigger and more expensive heat pumps when variable renewable generation may be low. Thermal energy storage and preheating inlet air are important to manage this problem. 

We must better understand our fundamental requirements for energy. And we must recognise that none of us actually want energy for its own sake: we want services we value or believe (and may really) need.

Not many people buy an air fryer or laptop computer because it’s efficient. They want to feed their kids quickly and use their laptop all day without having to plug it in. That’s an outcome of efficiency and innovation, not electrification or renewable energy. 

When our climate and energy minister describes efficiency as ‘embroidery’ for renewables and electrification and our appliance efficiency program is funded at under $15 million annually while, according to the Australian National Audit Office, it delivers $1.3 to 2 billion a year of benefits, it’s clear that we are seriously failing on sensible energy and climate policy.