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Manage household electricity demand with AS/NZS 4755-compliant products

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Standards Australia received the content for the following article from experts of the technical committee EL-054 Remote demand management of electrical products. The contributions thus of Mark Paterson (Chair), George Wilkenfeld (Drafting Leader) and Steven Humphries (Drafting Leader) are appreciated and acknowledged.

Demand management is about matching electricity demand to generation output (rather than the other way around) and is not a new concept. A well known example is the controlled load water heater, where the utility offers a low energy tariff in return for the right to switch the load on and off. Apart from managing peak demand, this is a cheap and reliable form of energy storage for the grid.

Standards Australia’s committee, EL-054, which covers demand management standards for various appliances and now battery storage systems, is an important piece in the smart-grid jigsaw. Under this committee, standards for the operating instructions during demand management events for air conditioners, electric water heaters and swimming pool pumps have been published. The most recent addition to this series is a standard on demand management for battery storage systems, the first of its kind in the world.

Tomorrow’s grid needs even more flexibility than ever, as increased use of renewable energy sources like wind and solar means generation output is more ‘intermittent’ and variable. Water heating time-shifting will continue to be an excellent example of a flexible load. Swimming pool filtration and pumping can also be time-shifted. The home cooling load, which has contributed so much to network peak demand and tariff increases, cannot be shifted from hot days, but it can be reduced by clever management of the air conditioners.

The phenomenal growth of rooftop PV has introduced a new factor into grid management, and the expected surge in home battery storage and electric cars will complicate matters even more. How will all this be managed?

We could leave it to electricity pricing alone, but research has shown that customers will stay with flat tariffs unless they can manage the risk of high prices. Receiving a text saying that the price has jumped to $2 per kWh, would not overjoy any customer, but especially if they’re at work with all their appliances switched on. Some appliance manufacturers offer a smartphone app that allows customers to switch things down or off remotely, but after a while this also becomes tedious. For most of us, life is too busy to constantly check electricity prices. Suddenly, the idea of letting a trusted third party manage your appliances, PV and batteries becomes very attractive, especially if they pay you for the privilege.

This management of appliances is made possible by the AS/NZS 4755 Demand response capabilities and supporting technologies for electrical products series.

AS/NZS 4755-compliant products have a standard interface (usually an RJ45 socket) to connect to an external “demand response enabling device” (DRED), which communicates with a “remote agent” authorised by the customer – the electricity distributor, the retailer or a load aggregator. The DRED passes instructions, or “demand response modes” (DRMs) to the end-use devices: DRM 1 “turn off” (i.e. minimise load but maintain power to electronic controls), DRM 2 or 3 “operate but at reduced load” or DRM 4 “turn on even if user-set controls do not call for operation right now.” DRMs 1, 2, and 3 are needed when the grid is load-constrained, and DRM 4 helps when the renewable energy available (from the home’s PV or the grid) exceeds the load.

Batteries may have up to four additional modes: DRM 5 “do not discharge to grid”, DRM 6 or 7 “discharge permitted at reduced load” and DRM 8 “discharge to grid requested.” The remote agent would activate DRM 8 when the value of export is high.

This world-leading demand response framework has taken 12 years to develop. It is simple, cheap, reliable and proven. There are over 850 AS/NZS 4755-compliant air conditioner models on the Australian market, and Energex now manages over 70,000 air conditioners connected to DREDs in southeast Queensland during a few critical periods. In addition, five AS/NZS 4755 batteries have been claimed as AS/NZS 4755 compliant by manufacturers/suppliers. These batteries systems are also currently being tested with Energex, a world leader in demand response.

Utilities and demand response aggregators are investigating DREDs with wifi, internet or 4G communications, and the pairing of the DRED to smart meters. There are other ways of achieving demand response, but these tend to rely on proprietary combinations of product and software, and may lock the customer into dealing with specific manufacturers and utilities.

AS/NZS 4755 is a true open standard: any 4755-compliant DRED will work with any 4755-compliant appliance. The communications mode of the DRED and the remote agent can all change, without having to change appliances. In fact, future DREDs could cut out the remote agent, monitor electricity prices and manage 4755-compliant products according to the customer’s pre-programmed preferences. Again, the appliances would not need to change.

AS/NZS 4755 is not a mandatory standard. Air conditioner manufacturers offer compliant products because under programs like Energex Peaksmart customers receive $100 to $400 for each PeakSmart air-conditioner when they connect to a DRED. The PeakSmart Program has shown that very few notice when the unit is made to operate at reduced load for limited periods. It is likely that utilities and demand response aggregators will offer similar incentives for other 4755-compliant products, including batteries. Manufacturers do not have to comply, but market pressures will be strong.

As the Australian market for this technology continues to grow, global players are taking notice. The AS/NZS 4755 series has and continues to be recognised internationally as an early and influential example of standardising demand response and load-matching functionality.

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