Switching to electric vehicles may save the planet, but there are challenges along the road.
The trend toward automotive electrification has established car makers and tier ones among the electronics industry’s biggest customers. We all continue to see a significant proportion of our activities and sales revenues associated with the drive for safer, cleaner, more reliable, and more entertaining vehicles.
Among the most interesting technologies is autonomous driving, which is bringing vast quantities of sensors on board – radar, lidar, infrared, camera modules – not to mention the signal processing and software needed to turn that data into real-time driving instructions. Then, of course, there is the transition to all-electric drivetrains, slated to become mandatory in several major markets by about 2030. With that, our takeover of the automobile will be complete!
Like many other consumer-electronic products, we can describe the generic EV drivetrain in a fairly straightforward block diagram: the battery and its management system (BMS), inverter, motor drive, and electric motor. Of course, nothing is as simple as it looks, and each of those blocks is an infinite source of technical minutiae to be understood, overcome, and perpetually re-engineered and re-optimized.
A key consideration is the powertrain operating voltage, which has important implications for us in the PCB industry. Increasing the voltage enhances energy efficiency and power delivery, and as some platforms are pushing toward 800V operation, we need PCBs that can handle this safely. It calls for a suitable comparative tracking index (CTI) to prevent arcing across the board surface that can cause component failures and fires.
High-CTI substrates were first formulated in the early days of domestic appliances, when substances – such as washing powder – were found to present a fire risk when they contaminated the board and arcing occurred. High CTI is also a requirement in applications such as electronic gasoline forecourt pumps for dusts or other substances that could promote arcing, leading to potentially problematic fires.
The CTI of ordinary, basic materials is under 100V, while so-called Level 3 materials can handle up to 175-250V. While today’s best materials can go up to about 600V, we’ve got work to do to raise the CTI for circuits operating at 800V and design and qualify suitable materials for future generations of EVs.
As I suggested earlier, the operating voltage is minutiae compared to some of the larger questions regarding sustainable mobility. Electricity lost the “battle of the fuels” to internal combustion a century ago. The situation is different now as today’s EVs are seen as the way to achieve a clean and sustainable future. But is this really accurate? As we work to build a future powered substantially by energy recovered from renewable sources such as wind and solar, the battery EVs we are driving today fit well with the vision. That green grid lies some way in the future, however, and moving rapidly to e-mobility is not so great for the planet today.
The technology needs customers in order to develop, and a cultural change must also take place. But EVs have some associated sustainability issues, particularly around the use of rare materials such as platinum, cobalt and lithium. Lithium battery technologies are by far the best we have. Right now, however, there is no satisfactory way to recover the metal from end-of-life batteries. An article in Nature suggests an average single car battery pack contains about 8kg of lithium and the world currently has enough reserves – about 21 million tons – to sustain conversion to EVs until the middle of this century.
What are the alternatives? Synthetic fuels could be an option. Biodiesels are already widely used in industrial applications, not only in road-going vehicles but also small boats and generators. Hydrogen and fuel-cell vehicles have for a long time been seen as an alternative to battery EVs and could make up a part of the e-mobility mix. However, the electricity needed to produce hydrogen by electrolysis is subject to the same caveats as electricity for recharging EVs: a cleaner grid based on renewable energy sources is needed before we can fully realize the environmental benefits.
One alternative could be nuclear. It’s free from carbon emissions as well as the geographical constraints on wind, solar and hydro power, although public perception is mixed. If that perception could be changed to recognize its track record as one of the very safest sources of electricity production, nuclear could produce more than enough energy to power the change to e-mobility; a sustainable way to produce hydrogen at low cost and recharge our lithium batteries.
Ultimately, no obviously problem-free way exists to get rapid, clean personal mobility in the style we have enjoyed since the first “motor cars” appeared nearly 140 years ago. Many technical challenges need to be overcome. But, we are technologists. Of course, we can do it. It may be expensive, however. While some predictions claim EVs will reach price parity with conventional combustion-engine vehicles by about the mid-2020s – due, in part, to the rapidly falling prices of lithium batteries – it has been calculated that the grid upgrades needed for them to become our preferred transport will cost $1,700 to $5,800 per vehicle. As Kermit the Frog said, “It’s not easy being green.” •
Alun Morgan is technology ambassador at Ventec International Group (ventec-group.com); This email address is being protected from spambots. You need JavaScript enabled to view it..
