Williams looks to use racing car batteries for home storage
“For us, Formula E acts as a proving ground for high power batteries working in harsh environments,” said Paul McNamara, Technical Director at Williams Advanced Engineering. “We have been able to fully test and validate our cooling systems, charge retention and module design, and apply this technology to other projects outside of motorsport.”
“One of the key issues that we have wanted to address is the vibration and track loading demands of the street circuits used in Formula E. With new Formula E tracks being built specifically for the series on public roads, we had to make a series of assumptions in our original design without any data. Another difficulty was thermal management, given that batteries heat up rapidly when used in a harsh environment like a race track. Now, with real-life experience of the race locations over the course of two seasons, we’ve been able to incorporate improvements in these two areas. Another breakthrough for us was the power increase between season one and two. In season two the batteries are operating at 25% extra power during a race than they were initially designed for.”
In season two the batteries have had to deliver 850kWh of power and that will have to double for the current season, enough to power the avage home for four months. This has lead to some major engineering challenges in cooling and maintainability, he says. “All the cells in one battery work in a series, so each cell needs to be cooled and controlled well in order to perform. With street circuits tending to be quite bumpy, maintainability is important as well, and we have already been able to redesign some of the features for improved performance and reliability.”
“We can measure the battery performance during each session, and crucially the temperature of each individual cell to monitor how well the thermal management is working. In fact, the cells are so well managed that we are looking for second life applications for those from season one which would still be good for static storage applications, unlike the kind of battery you might find in a laptop or phone which would have a more limited life because of less thermal management,” he said.
Williams’ experience with batteries and energy storage started in Formula One with the KERS (Kinetic Energy Recovery System) for the Formula One car, and that was extended to the technology for the Jaguar C-X75 hybrid concept car, learning more about battery behaviour. “Following on from the Formula E project, we have created a fully electric concept car for Aston Martin, the RapidE, and a battery to power a fully electric version of the Range Rover Evoque, and we currently have a number of battery related projects on the go with major automotive OEM’s,” he said.
The Formula E races allow Williams to push the technology further, he says. “The championship really is a point of innovation for electric road cars. We’ve been able to test and validate various aspects, such as safety requirements, which are important considerations in the creation of electric vehicles. Things such as flammability, cooling, crash testing and potential leaks have all been evaluated in Formula E and now massively influence our design when developing systems for road cars.”
Changes to the race will push the technology further. “Season five will be a great example of Formula E acting as an incubator for technology, when there will be one car per race as opposed to the mandatory car swap in place at the moment,” he said. “Whoever wins that tender will have to double the energy available in the same mass, which is something we have already looked, from the battery integration, cooling system, power output and weight.”
Before joining Williams Paul worked as an Executive Director at Shanghai Automotive Industries, based at their Technical Centre in the UK, but working for much of the time in the Chinese operation as part of the global team to set future product direction and deliver current programmes to market. Prior to SAIC he worked for more than 20 years at Ricardo during which time he was the UK Engineering Director for five years and Managing Director of the UK divisions for a further five years. During his time at Ricardo he directed major projects for key customers such as Ford, Volvo, Hyundai and McLaren.