Hundreds more Victorian households will get solar panel rebates after a surge in interest for the state government scheme.
It comes after about 600 households went ahead with installation without making sure they were eligible for the first stage of the government's half-price scheme, the inaugural head of Solar Victoria Stan Krpan says.
"Householders have installed but didn't follow that important rule of applying for eligibility first," Mr Krpan told ABC radio on Wednesday, adding he believed they acted in good faith.
"The only way to guarantee that you're eligible is to come through us, tick off all the boxes. Then we give you an eligibility number then you can go confidently to your installer."
The Andrews government announced the creation of Solar Victoria in August as part of its plan to install solar panels on 650,000 homes across 10 years.
Under the first part of the plan, solar panel purchases were eligible for a rebate on up-front costs.
It was initially capped at 24,000 before being lifted to 32,000 amid a surge of interest.
The scheme shifts to a part-payment system combined with a four-year interest-free loan from July.
"In those last couple of days we think that there's about 600 householders who might have been locked out, who have installed but not applied for the rebate,:" Mr Krpan said.
"What we're saying if you installed by the 12th of April, which was the last day of the scheme, effectively we'll give you until the 14th of June to apply.
"But it's only for that short window to make sure people who were acting in good faith are not disadvantaged."
Before being appointed to lead the implementation of the government's solar promises - including for hot water systems - Mr Krpan led significant law, health and safety reforms with Sustainability Victoria, the Environment Protection Agency and WorkSafe Victoria.