Guernsey Electricity and Guernsey Post are on track to complete the installation of the solar photovoltaic (PV) system on the roof of the postal headquarters at Envoy House in October.
The partnership was announced a year ago as Guernsey Post entered the final stages of converting its delivery fleet from diesel to electric vehicles.
To offset the increase in carbon emissions, Guernsey Post has invested in 82 electric vans and partnered with Guernsey Electricity to link the electricity usage of these vans with the carbon reduction created by using the PV system as a generator supplying the grid.
The project progresses Guernsey Electricity’s introduction of macro scale renewable generation which is owned and operated by the company, the first being the power station roof. It also includes the installation of more than 50 charging points on the site.
Chief executive of Guernsey Post Boley Smillie said: 'We are excited that the project completion date is nearing where all islanders will have access to even more renewable energy.
'As a business this will help us to continue our efforts to reduce our impact on the environment.'
The 654 panels installed will produce more than 200,000kWh each year, which is equivalent to the electricity required to power the 82 electric vans with some energy to spare.
The electricity generated will be supplied to Guernsey Electricity for the grid, so all electricity customers will access locally produced solar energy.
Chief executive of Guernsey Electricity Alan Bates said: 'We are delighted with the progress of this project and are keen to see the PV system being used to its full effect.
'We are now concentrating on connecting the system to the wider Guernsey Electricity network, enabling the Island to diversify its energy supply.'