Voltage limits for Queensland’s electricity networks are set to change, bringing the state into line with Australian Standard (AS) 60038 and international best practice. This will enable more solar power systems to be installed – and with less red tape.

Queensland’s Department of Natural Resources, Mines and Energy announced last week voltage limits in Queensland will change from 240 volts +/-6% to 230 volts +10/-6% this year. The new “preferred” operating range will 230 volts +6/-2%.

The major reason for the change has to do with solar power. More than 546,000 solar power systems are installed in Queensland and self-consumption/exports have resulted in issues with network voltage levels rising in some areas, accompanied by the risk of problems with appliance performance or damage.

Voltage Issues Costly, Restrict Solar

In 2016, Energex and Ergon Energy reported around 1,000 complaints from customers related to solar panels and high network voltage. Aside from the frustration to customers, it was costing $2,200 on average to deal with each complaint, plus insurance claims for appliance damage. These and associated network upgrade costs are ultimately passed on to electricity customers.

“To control voltage rise in the past, electricity distributors Energex and Ergon Energy invested significant resources upgrading the network and tightened their solar photovoltaic (PV) connection requirements,” says the Department. “This made it harder, and in some cases more expensive, for customers to connect an exporting solar PV system to the grid.”

Continuing a business-as-usual approach would have resulted in 10 per cent of new applications for new rooftop generation (around 200 per month) requiring modification or being refused. Some applicants would be required to pay an additional cost of between $10,000 and $60,000 toward a network upgrade before a system is installed; effectively making solar a no-go. The situation would have also seen a continued practice of restricting electricity feed-in for some system owners.

More Wiggle Room = 200,000 More Solar Systems

The flexibility for distributors to operate at a lower voltage “floor” limit and decreased incidence of bumping up against the ceiling level will enable more solar power systems to be connected and without so many hoops to jump through says the Department.

It’s a significant number – an estimated additional 200,000 systems or 960 megawatts of capacity could be added as a result of the change. It should also mean less tripping of inverters in existing systems in areas where high voltage issues have been occurring, plus less expenditure on network upgrades.

Status Quo “No Longer Appropriate”

The nominal voltage in Australia was set at 240V nearly a hundred years ago. However, most of the world’s appliances are designed to operate optimally at 230V as a result of the International Electrotechnical Committee (IEC) deciding on 230V as nominal in the early 1980’s. This difference, according to a Regulatory Impact Statement (RIS) published last year, has been costing $400,000 per year in reduced appliance life in Queensland and was considered no longer appropriate for a contemporary electricity network.

“The narrow 12 per cent operating range is inconsistent with the more progressive uniform standard of 230 volts +10 per cent/-6 per cent accepted elsewhere in Australia and overseas, and its permitted 16 per cent range,” said the RIS (PDF).

The Clean Energy Council said the change was “sensible reform”; one it had been advocating for many years.

“Western Australia is now the only state that still relies on the outdated 240V limit,” says the CEC.

If you’ve had problems in the past in getting solar panels installed in Queensland due to network voltage issues and given up in despair, it might be time to start re-examining going solar. Energex and Ergon Energy must comply fully with the new voltage limits from 27 October 2018.