It’s time for a plug-in revolution: The harsh reality of trying to drive electrification and PV for apartments

The recently released report of the Victorian parliamentary inquiry into ‘Renewable and Affordable Energy for Apartments’ provides extensive evidence for the need to switch our focus from grid-sourced energy supply and to consumer-side measures and the plug-in revolution

The proposed processes outlined by the report involve cumbersome and expensive measures. It takes a long time to upgrade network and building-level electricity infrastructure.

We don’t have enough electricians. It involves owners corporations and managers, dealing with remote apartment owners, split incentives and other complications. And there is much less solar generation in winter, when transition from gas is expected to increase already high amounts of potentially expensive electricity in extreme weather.

Of course, we should try to accelerate the actions proposed in the report for both existing and new apartment buildings and other renters, including many small businesses. But they will be slow and costly. 

We must aggressively focus on consumer-side of the meter efficiency, energy storage and smart management. This is the ‘plug-in revolution’ I have been advocating for some time.

This goes far beyond balcony solar and building or apartment-level batteries, and involves appliances as well as building thermal performance. It also requires some significant, but straightforward technology innovation.

To understand how and why this is needed, we have to start at the point of electricity consumption.

The parliamentary report highlights the fragility of electricity supply to many older apartments. Some have had to limit apartment consumption to less than 25 amperes of current whentransitioning from gas – equivalent to a maximum peak limit of 5.75 kilowatts of power per apartment.

New homes typically have over 60 Amp supply and many even have 3-phase power. So this sounds like a serious barrier. This must be seen in context. 

On one hand, if you want to install an induction cooker, it may be rated at a maximum demand of 10 kilowatts, well above the available maximum. This flags a need for a major power supply upgrade. But that need not be the situation.

If the maximum available 25 amp capacity was used continuously over 24 hours, it could deliver around 140 kilowatt-hours per day. A typical all electric home uses 15 to 25 kilowatt-hours per day.

Of course, in winter and summer extremes daily consumption might rise to 40 kWh/day or, for inefficient high consumers, maybe 100 kWh/day – still well within that daily supply capacity. In principle, a battery behind the meter could smooth this demand within present wiring limits. 

Based on the enormous costs quoted in the parliamentary report for network and wiring upgrades, this might be cheaper. But it would also be incredibly wasteful and unnecessarily expensive.

We must remember that existing apartments use inefficient electric appliances as well as gas appliances. Modern appliances and equipment in a thermally good building have much lower demand and consumption.

However, some modern appliances, especially induction cookers, still have relatively high peak demand, usually for relatively short periods. So we need to manage demand while delivering the services occupants want or need.

‘Smart’ small batteries, either integrated into appliances or as a ‘black box’ at the power socket, possibly with standardised swappable batteries, can smooth and reduce demand – they don’t have to replace all demand unless there is a power outage, they just have to keep demand within available limits. 

The following text shows what’s possible.

A 2 kilowatt reverse cycle air conditioner produces as much heat as 4 or 5 electric fan heaters that would create an electricity load of 8 to 10 kilowatts. A high thermal performance apartment would require a RCAC of less than 1 to 2 kW electric, though it may have higher demand for a while when warming up an apartment. 

A typical heat pump hot water service uses less than 1.2 kilowatts when heating, and uses 1 to 3 kilowatt hours per day. A traditional electric HWS has an electricity demand of 2 to 5 kilowatts and consumes 5 to 10 kilowatt-hours per day.

Modern LED lights consume around 2-3 watts per square metre. Many homes still have halogens that consume 20 watts per square metre – and can’t be covered by insulation because they get so hot. So they increase heating and cooling energy requirements.

The best family fridges now use 155 kWh/year – less than 20 watts average – 60 to 80 percent less than a lot of old fridges. When the compressor is running and during defrost, demand is higher, but still just a few hundred watts.

A 10 star 8kg heat pump clothes dryer uses under 2 kWh per load with demand at around 1.2 kW, compared with traditional dryers with demand around 2 kW.

A dishwasher that consumes around 0.5 to1 kWh/wash at 2 kilowatts demand takes about 7 minutes to heat 5 litres by 40 degrees and uses 0.233 kWh. It uses a similar amount of electricity for the drying cycle, but it would have time for the battery to recharge before drying. The rest of the time it uses much less power to drive a pump and some electronics. So a small built-in battery or plug-in battery that limits grid demand to 1 kilowatt could easily cope.

The big issue for many people is the induction cooker. While some are rated at 10 kilowatts or more peak demand, that is for all hotplates working hard. A single hotplate’s demand is between 500 and 2300 watts. It will boil a litre of water in about 3 minutes using 0.1 kWh of electricity.

So the high peak demand is for short periods. Again, a small battery could limit demand. Indeed, a recent article ( Why thousands of New Yorkers swap gas for induction stoves in clean energy push: ‘It makes sense’ | US news | The Guardian ) outlines how New York apartment dwellers with limited electricity supply capacity are adopting induction cookers with built-in batteries. These also solve the problem of cooking during a blackout.

Many also focus on the emerging need for Electric Vehicle charging – and their potential use to run the home. An average Australian car travels around 35 kilometres per day – an EV requires about 6 kilowatt-hours to supply this. That’s about 3 hours on a standard 10 amp powerpoint.

It’s about 13 kilometres added per hour. A smart charger could divert more power to a charger when it is available. Remember, a 25 amp apartment supply can deliver 140 kWh/day. To charge for 400 kilometres per day would require 50 to 80 kWh.

This approach can be implemented much faster and more cheaply than the supply side solutions that are being proposed.  And we won’t need as many electricians. We just have to break free from the past.