Smart solar power hub heats up

More than 2500 smart meters have been deployed in homes across the Illawarra region of NSW under a plan to link with hot water systems to help manage the increasing number of residential solar PV systems across the electricity network.

The smart hot water program known as Off Peak + is being rolled out by NSW electricity distributor Endeavour Energy, in partnership with Australian and New Zealand metering provider and data intelligence business Intellihub.

The program will replace last-century ripple control technology to manage hot water load control, but also help regulate voltage across the grid — a potential impediment to increasing solar load being exported to the main electricity network.

The smart meter can also be used to dynamically control each hot water system by Endeavour Energy or any of the 10 electricity retailers participating in the program. This means hot water systems can be switched on to soak up solar energy on low-demand days when large amounts are being exported to the electricity grid.

The smart meters have been installed in homes supplied by Endeavour Energy’s Albion Park Zone Substation. Data is now flowing from the meters to its network operation centre and further rollouts across homes in Western Sydney and the NSW South Coast are being planned.

Smart meters used to replace last-century technology

The Albion Park Zone Substation was commissioned around 1970 and powers 10,000 homes and businesses. About 25% of homes in the area have rooftop solar panels installed and more than 2500 homes connected to the substation also use electric hot water tank systems for their hot water needs.

A hot water load control unit at the substation sends a signal via the local electricity network to a receiver on customer switchboards, which turns their hot water systems on and off at different times of the night and day — it is known as a ripple control system. The system can only operate as a whole. Individual hot water systems are not operated as individual units.

The customer pays a cheaper tariff for their hot water energy use. In exchange, Endeavour Energy can defer electrical load outside peak times, which helps keep its substation operating within safe levels and defers the need for potentially costly capital upgrades.

This type of system has been in place in NSW since the 1950s. The hot water tanks effectively act as energy storage systems. About 6 MVA of electrical demand is supplied by this hot water load control at the Albion Park Zone Substation. About 85% of Endeavour Energy’s zone substations are equipped with these sorts of systems, controlling the hot water supply for about 300,000 customers.

Rather than replace this ageing system with similar technology, Intellihub installed advanced smart meters in switchboards at the customer premises in Albion Park to communicate with each hot water system.

The solar sponge

Intellihub has designed systems to allow Endeavour Energy and any of the participating electricity retailers to turn on the hot water systems for additional time during the middle of the day.

It means retailers can develop virtual power plant-style products. For example, hot water systems can be used as solar batteries, where they are charged during the day when there is an oversupply of electricity in the market due to solar generation.

It means solar generated in the community on local rooftops will be shared and used locally via hot water systems. It will allow electricity retailers to offer innovative new products, with incentives for consumers to take part. The smart meter will also be able to support any future solar PV systems at customer premises.

Data is the key to facilitating increasing residential solar systems

It is hoped the program will facilitate the growing number of solar PV systems being installed at homes across the country. Here, data is the key ingredient.

Australians are adopting solar energy faster than anywhere else in the world — up to 10 times faster. The number of systems is expected to triple by 2030.

Endeavour Energy expects that as many 35,000 of those systems will be installed in homes connected to its network each year.

At present most electricity distributors do not have visibility of power flows across their low-voltage street network. The increasing saturation of residential solar energy in many parts of Australia means excess energy flowing into the grid can cause problems with voltage regulation.

The networks cannot always see or predict when and where this is happening.

One way to manage this issue is to limit the number or size of solar systems being installed. Not an ideal solution for homeowners wanting to take part in the clean energy transition across the country.

An even harsher measure is to shut the systems down when required, or even cut power to whole areas to prevent damage to the network or maintain a safe supply.

The Off Peak + program offers a smarter alternative for industry, regulators and consumers.

It can provide access to real-time data about the state of the network at the street level and it will allow Endeavour Energy to manage the voltage on the network in a smarter, more dynamic way, to allow more and more solar to connect.

It will also alert them to problems with safety and reliability of supply.

Extending the benefits of smart meter technology

This use of smart meter technology is building on an already impressive tool kit of applications.

We know the technology enables remote connection services, monthly billing and the elimination of estimated bills via remote reading.

But we are now starting to understand a much larger suite of uses to help our shift to renewable energy.

Today, smart meters give insights in real time; optimise the home for solar, batteries and electric vehicles; and enable new services like demand response and virtual power plants and dynamic control of hot water.

They are fast becoming a key enabler of the clean energy transition that opens doors for community and household participation.