Scotland's largest solar farm, which will provide power for more than 3,500 homes, is due to be officially opened.
The 13MW scheme, which was constructed on 70 acres of land at Errol Estate in Perthshire and includes 55,000 solar panels, went live in May.
Paul Wheelhouse, the Scottish government's minister for business, innovation and energy, will formally launch the solar farm.
Its construction began in January. It generates energy all year round.
Errol Estate was one of the first locations in Scotland to be identified as a potential solar farm site, with the land being promoted for development by Thomas Macmillan of Savills in 2011.
'Appetite from developers'
Elgin Energy secured planning permission for the farm, and was responsible for designing the scheme and grid connection.
The farm was built by Canadian Solar, which will also operate the project.
Mr Macmillan said he was "delighted" to see power being generated at the site.
He said: "It has been four years in the making and proves that large-scale solar in Scotland continues to be commercially viable.
"Solar technology has a far greater role to play in Scotland's energy mix than many people might realise.
"Due to reducing installation costs, and a climate of support from Scottish government, we are continuing to see an appetite from developers to take forward new development sites, even with reducing subsidy support from the Westminster government."
Mr Wheelhouse said: "This very substantial and impressive project is proof that large scale solar photovoltaic systems work well on the east coast of Scotland and I am also greatly encouraged that a variety of organisations are continuing to source solar sites across the country, with a view to developing financially viable schemes."