Apart from lithium consumption and aluminum for light-weighting, it is unusual for the hybrid car market to cross paths with metals consumption stories but a recent article in the Economist details a technological development in the automotive industry that will be of interest to both.
To anyone of even a mildly geeky nature, the Economist makes interesting reading drawing on history, new developments and the future path of electrical automotive technology. In brief, the issue is car voltage.
Historically, cars started with six-volt systems but in the ’50’s — as vehicle’ electrical systems increased in complexity — the voltage was increased to 12-volt to cope with more onboard appliances, electric starters and so on. Well few things stand still in the automotive market and in spite of acute cost pressures, designers are starting to introduce 48-volt systems and are hoping, as adoption picks up, costs will come down.
What Are Those Extra Volts For?
First, what is driving it? Well, as the Economist explains, one reason is that cars are packed with more and more components, demanding more and more electrical power. A modern vehicle may have as many as 150 electric motors and new features like stop-start technology. These are putting strain on car systems, particularly those with high-compression diesel engines.
The other reason links back to the development of hybrid and electronic vehicles. Extra voltage allows designers to boost efficiency and reduce emissions. For example, during braking, the starter can act as a generator converting kinetic energy into electrical energy and storing it.
Operating at 48 volts allows more power to be generated and stored. This power can then be drawn on later to provide “torque assist” where the starter acts as an additional motor, helping the car accelerate. Work is being done to take this to the point where — in a steady cruise — the torque assist takes over from the engine, significantly cutting fuel consumption and emissions.
Arguably hybrids can benefit more from such technological developments than either conventional or pure EVs, employing as they do multiple electrical motors, complex electrical systems. They can maximize the return from generally smaller engines. Not surprisingly, Audi – winner of multiple Le Mans 24-hour races in their cutting edge hybrid race cars — is pioneering the move and already employs 48-volt systems on its SQ7 luxury SUV, even though the current version is not a hybrid.
Audi uses a 48-volt system to run, among other systems, an electrically driven turbine to force extra air into the engine under load, giving a faster response time than a turbocharger. The car also uses 48-volt systems to run the self-leveling suspension, allowing — Audi says — faster response times and a smoother ride.
More Electrical Motors… More Conductors
It is expected that until costs come down for 48-volt components, a trend that will require more volume demand and manufacturing, cars will employ 12-volt systems for lights, media and general electrics but a separate battery, circuit, generators and motors for high-performance functions that can take the greatest advantage of higher voltage systems.
Where does metals consumption come into this? Beefed up electrical systems will boost copper, silver and battery demand in one of the largest metal consuming industries. 48-volt systems for the foreseeable future will require cars to carry two batteries, a conventional lead acid for 12-volt operations and currently a lead-carbon or lithium-ion for the 48-volt circuits.
The improvement in performance and emissions is apparently considerable, today’s 1.5-liter turbo-charged engines already outperform yesterday’s two-liter engines, but tomorrow’s one-liter engines running on 48 volts are expected to be even better still. Audi is not alone, Ford is also running an extensive research project with help from various academic institutions. If ever there was an industry that has moved away from the bigger is better to the smarter is faster ethos it is the automotive industry.