The BMW Group is resolutely focusing on sustainability during the construction of its new plant in San Luis Potosí in Mexico. It is in a position to do this because comprehensive lessons were drawn from experience gained in planning and operating former plants. The outcome is likely to set milestones.
San Luis Potosí lies in the middle of a semi-desert in Central Mexico. Despite this, the region is rich in a variety of flora and fauna. Yucca, agaves and cacti dominate the landscape and endangered armadillos, adders, iguanas and a myriad of small animals cavort in its shade. In this sparsely populated region, the BMW Group is currently constructing a new plant comprising a body shop, paint shop and assembly line. Starting in 2019, it is expected that around 150,000 units of the BMW 3-Series will roll off the assembly line here. Around 1,500 employees will be recruited for this. It is not just production that the BMW Group has ambitious plans for: the new plant in San Luis Potosí is expected to be the most sustainable in the BMW Group’s worldwide production network.
Sustainable production process in the new paint shop
This can be seen in the new paint shop where different successful concepts of other BMW Group plants are being brought together into one smart factory for the first time: the paint shop is adopting an integrated paint process (IPP) from the BMW Group’s Oxford plant. This means that the plant in Mexico can also dispense with an otherwise standard primer coat that impacts the environment. Instead, two innovative layers of paint that are applied as a primer before the actual painting ensure colour brilliance and evenness. To filter overspray out of the air, BMW uses a procedure developed at the Regensburg plant in Germany during which paint is bound by stone powder. In comparison to the usual rinsing process with steam, it saves water and allows for up to 50 percent of the residual paint to be reused. “By combining this with other procedures, we will be able to use less water and chemicals in the paint shop,” says Dulce Cruz, Environmental Manager of the plant. As a result, special cleaning of the air is not necessary, and around 60 percent of the energy usually required for this can be saved in the Mexico plant.
Building blocks of sustainability
Saving water and energy was also the reason why the BMW Group opted for a closed cooling water circuit. Although it is more expensive to maintain than an open circuit, it consumes relatively less energy. As the flow and return flow temperature are continuously compared at a collection point, it is not cooled “on spec”: Only as much cooling water as the machines actually require is used.
Various other methods for managing water and energy efficiently are building blocks that help to lay the foundation for our most sustainable automotive plant: Some of the water for the sanitary facilities is acquired from purified rainwater. The lighting system consists entirely of LED lights. The forklifts on the site are powered by an electric drive rather than by a combustion engine.
Energy efficiency at the plant in Mexico also involves the location producing its own energy. “To generate electricity we use a photovoltaic system covering 70,000 square metres. This allows us to cover around 20 percent of the electricity demand of our new location ourselves,” says Dulce Cruz. The remaining 80 percent is expected to be obtained from a regional provider that generates electricity using wind power.
“We understand sustainability to also include taking responsibility for sustainability education and training,” says Cruz. The BMW Group has therefore entered into cooperation agreements with local educational institutes. “Our experts are thus able to share their sustainability expertise in the classroom and pass on their experiences. We have already reached more than 5,000 young people with this educational programme,” says Cruz.
On a side note, the flora and fauna in the area of the new plant are also part of the sustainability concept. In order to preserve the diversity and interfere with nature as little as possible, over 150,000 plants have been relocated by experts. What’s more, armadillos, adders and iguanas that have gone astray nearby will be carefully gathered and released in the nearby national park by animal protection experts.