The solar farm will be developed on council-owned brownfield land next to a household waste recycling centre, where the vehicles are based.
Newport has seven electric refuse vehicles and said it planned to continue replacing diesel trucks with electric versions over the next few years.
An electricity substation already at the site will reduce grid connection costs, the local authority said.
Cabinet member for climate change Yvonne Forsey said: ‘We are committed to reducing our carbon footprint and the solar farm will make an important contribution to our ambition to become a net zero council.
‘Generating our own renewable energy to use in all the authority’s refuse vehicles will not only reduce fuel costs but also help us in our drive to further improve air quality in Newport.’
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