Solar industry installers, solar panel owners and supporters are voicing their opposition to the NSW government's decision to retrospectively slash tariffs to existing subscribers.
Greens MP John Kaye labelled the move as "semi-unlawful" and said it would hinder the state's push towards a clean energy future.
"It will squander investment in renewable energy," Mr Kaye told reporters on Wednesday.
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"It's a semi-illegal move."
Mr Kaye called for a one-for-one feed-in tariff so energy companies pay the same for solar energy generated by households as they make households pay from electricity produced by coal-fire.
NSW Energy Minister Chris Hartcher on Friday announced the scheme will no longer be open to new applicants.
Most of the existing 120,000 subscribers receive 60 cents for every kilowatt hour of electricity they generate from their solar panels.
Retrospective legislation will be introduced to slash that rate to 40 cents.
John Grimes, chief executive of the Australian Solar Energy Society, urged the protesters to contact independent MPs, saying it would be the only way to stop legislation passing parliament on
Tuesday.
"We need two more votes ... there are four independent members, they will decide it," Mr Grimes said.
"We will not back away from this fight. We will use every method at our disposal."
He said people should contact the Christian Democrats and members of the Shooting Party.
The protest organisers told AAP there were about 1500 people at Circular Quay.
They were chanting "save solar today" and carrying banners such as "Chris Hartcher equals Tariff snatcher" and "The future is solar".
