Homes across Perth and WA’s south face widespread blackouts within a few years according to a bombshell report that calls for urgent upgrades to the system to accommodate rocketing levels of renewable energy.

The Australian Energy Market Operator, which runs the south-west electricity market, said there was now so much solar power flooding into the grid at certain times the system risked becoming “inoperable”.

Energy Minister Bill Johnston said he agreed with the report’s findings, and the State Government had launched a plan to deal with the problems it identifies.

AEMO warned if nothing was done to safeguard the grid by next year, there was a “credible” danger of rolling blackouts from as early as 2022 as soaring levels of renewable energy periodically overwhelmed the system.

At worst, AEMO warned there was a “real risk” of a system-wide blackout.

To head off the problem, AEMO wants all new solar panels to be installed with “smart” inverters that would allow output from those systems to be pared back or switched off in emergency situations, with customers to pay for the devices.

It has also called for investment in new hardware known as “synchronous condensers” to help strengthen the system, along with large-scale batteries to soak up excess solar power during the day and provide back-up electricity at other times.

Central to the market operator’s concerns is the rapid growth of rooftop solar, which cannot be controlled like traditional generators such as coal- and gas-fired power plants.

There is now about 1000MW of rooftop solar installed on the grid, making it the biggest single generator when combined, with forecasts this will more than double to 2400MW by 2028.

On top of this, AEMO noted there was also a large and growing amount of large-scale renewable energy such as wind farms coming on the system. Peak demand last year was 3600MW.

AEMO said output from solar panels was hollowing out demand for power from the grid during the middle of mild, sunny days when demand was low — typically in spring — to such an extent the system would soon be in breach of technical limits.

Those limits are in place to ensure that voltage and frequency levels are maintained within carefully prescribed levels to ensure the system was safe and devices such as those in people’s homes were not damaged.

But AEMO said the levels would be difficult to maintain once demand from the grid — or operational demand — fell lower than 700MW. Below this level, it said, “traditional thermal” plants which provided the services that buffered the system struggled to stay on because the grid would be overloaded.

“At a minimum operational demand and synchronous generation level of less than 700MW, voltage control is problematic resulting in unsecure operation and high likelihood of cascading failures on the system,” it said.

“The worst-case scenario is the real risk of a (south west interconnected system) blackout due to cascading failure or widespread load shedding if no action is taken now to implement the technologies and regulatory reforms to support secure operation... renewable generation technologies.

“As the SWIS approaches a minimum operational demand level of 700MW, it will become increasingly unstable, requiring increased frequency and extent of intervention by AEMO to maintain power system security.

“Various forms of network investment to maintain system security will be required in addition to reforms to the ancillary services framework.”