Sutherland Courthouse will be one of the first to be fitted with solar panels under a new program to make the state's judicial buildings energy efficient.
Energy-saving LED lighting, along with motion sensors in non-court areas, will also be installed.
Attorney-General Mark Speakman said Stage 1 of the program would fund the installation of more than 3000 photovoltaic solar panels on 23 courthouses in metropolitan and regional NSW.
The upgrades will begin early in 2022 and are due to be completed by June.
There will also be a trial at some courthouses of smart electricity metering, batteries to store unused solar power, and electric-vehicle charging stations for departmental vehicles.
"Courthouses in Stage 1 will generate an estimated 2311 MWh of electricity per year - enough to supply a significant proportion of the buildings' power, reducing carbon emissions by the equivalent of 360 average residential households," Mr Speakman said.
Treasurer and Minister for Energy and Environment Matt Kean said the $1.8 million rollout supported the NSW Government's commitment to halve the state's emissions by 2030 and achieve net zero by 2050.
Mr Kean said court houses would join schools, hospitals and other government buildings in the uptake of solar energy, which would help NSW double solar energy generation to 126,000 megawatt hours (MWh) by 2024.
Sign up for our newsletter to stay up to date.