Bordeaux’s mayor, Pierre Hurmic, a member of the Green Party, has set the ambitious goal of becoming a ‘solar city’.

In order to achieve this, he intends to cover the Bordeaux ring road with solar panels, and recently the préfecture has taken the first steps toward that project. 

The eventual plan is to have huge see-through canopies over the road – at a height of 17 metres – which incorporate solar panels.

Où en est le projet d’ombrière solaire sur la rocade de Bordeaux ?https://t.co/VV41cjemNu pic.twitter.com/iKFMi0J86y

— Sud Ouest Bordeaux (@SO_Bordeaux) September 8, 2023

In a press release sent out on Monday, the Gironde préfecture announced that the inter-departmental roads body (DIRA, or Direction Interdépartementale des Routes Atlantique) was seeking bids from companies who would want to install solar panels.

This represents the initial phase of the project and the solar panels would be placed over several slip roads, the first bid is for motorway access ramps numbered 15, 19 and 22, in the municipalities of Pessac, Villenave-d’Ornon and Bouliac.

READ MORE: Analysis: The solar revolution in rural France

The project would initially cover “around seven hectares in the immediate vicinity of the Bordeaux ring road”, the press release specified.

Officially, the préfecture told French news website 20 Minutes that adding solar panels to the motorway exits is “not linked to the plan of covering the ring road”, but Hurmic sees it as a crucial first step.

“It is totally in line with our request for a trial, and I think it’s a very good idea to start experimenting with on-ramps. If the experiment is a success, then I would like to see it extended to the entire ring road,” he told 20 Minutes.

How the ‘solar’ motorway would work

The Green mayor ran for office in 2020 with plans to help Bordeaux’s energy transformation – with the goal of reaching a 41 percent ‘energy autonomy’ by the end of his mandate. In 2021, he started discussing the mammoth plan of installing solar panels above the entirety of the city’s ring road.

The job would take several years to complete, counting around two million solar panels covering 45km of motorway, but it would produce the equivalent 40,000 households’ total electricity consumption (out of a total 389,845 in the greater Bordeaux area, as of 2018). 

The solar panels would be installed at a height of 17 metres, similar to those that have been used to cover car parks in other parts of France, but the motorway versions would be see-through.

READ MORE: France set to make solar panels compulsory in all large car parks

The initial estimates show that the project – if approved – could end up as France’s largest urban solar power plant, but it would also cost upwards of €3 billion, TF1 reported.

According to the group of engineers leading the project – Etude d’Architecture & d’Urbanisme – the investment would be paid off in seven years.

Eventually it would help the metropolitan area save up to €672 million a year, spokesperson for the group, Jean-Claude Laisné, told Le Figaro.

Aside from requiring a large budget, the plan is also not exactly under the purview of the city. The ring road technically falls to the State and regional authorities, and it will take a number of different stakeholders to sign on.

In an interview last September with Sud Ouest, the Ministry of Transport said that “the project is ambitious and complex, and contacts are being made to determine its scope and to study its feasibility and, if necessary, support the local authority in making it operational”.

What else does the mayor want to do?

The mayor intends to meet his clean energy goals by building bicycle lanes, solar panels at car parks, and a large-scale solar project to cover the Bassin des Lumières, which was originally a submarine base built by the Germans during WWII but now serves as a cultural space.

This would cover a rooftop space of 13,000m2, the mayor told 20 Minutes, creating the equivalent of 130 households’ electricity per year. 

“I think that Bordeaux can be a pilot city in terms of promoting solar energy, but for that to happen the municipality itself must be exemplary,” Pierre Hurmic told the French press.