Melbourne's trams network will soon be powered by the first large-scale solar plant to be built in Victoria.

The solar plant, which will be completed by the end of 2018, is expected to be located in Victoria's north-west.

The state government announced on Thursday that the solar plant would produce 75 megawatts of power, with about half of that production to be linked to the tram network.

Energy, Environment and Climate Change Minister Lily D'Ambrosio said the government would use its purchasing power as a "large energy consumer" to boost investment in renewables.