After years of unfulfilled promises, Victoria is on the cusp of getting its first large-scale solar power stations. Three farms in the state's northwest are promised to be operating by the start of next year.

Australian company Overland Sun Farming plans to start work in April on separate fields of solar photovoltaic panels at Yatpool, Iraak and Wemen, creating about 200 construction jobs.

With a combined output of 320 megawatts, they are expected to produce enough electricity to power Geelong, Ballarat and Bendigo when running at full capacity.

The $500 million announcement comes amid a heated political debate over the future of energy. The Turnbull government is attacking Labor state governments and the federal opposition for supporting ambitious renewable energy targets, and considering taxpayer funding for new coal-fired power stations.