This article is part of a short series on the history of EVs. You can find Part 1 here.
The Tesla Roadster
Both the compliance cars and the serious cars since 2010 have one big thing in common: they were forced into existence by pressure from the Tesla Roadster.
Like the newer non-compliance EVs, it had most of the key features of a modern EV. It was a pure EV, with no range extender, fuel cell, or any of that. It had great range (over 200 miles), a great user experience, was usable at any speeds a normal car goes, and good power. While expensive, it proved that an electric vehicle was a viable idea and not just a golf cart.
It wasn’t originally meant to be built on a dedicated EV platform, as Tesla planned to use the Lotus Elise’s frame and body to take advantage of existing economies of scale and not start from scratch. But, as the design progressed and little tweaks were needed here and there, the number of shared parts between the Roadster and the Elise shrunk until such advantages were gone.
By accidentally landing on a dedicated platform, Tesla learned the hard way that clean-sheet designs are the way to go. Other manufacturers went through similar learning experiences through the 2010s, trying to make EVs on shared platforms with gas-powered versions of a vehicle and hybrids, and had problems of their own.
So, really, the Roadster is the parent of all modern EVs not only because it forced automakers to make EVs, but also because it proved out most of the basic architectural elements that today’s successful EVs all use.
The AC Propulsion tZero
The idea to build the Tesla Roadster didn’t come out of thin air. The AC Propulsion tZero electric roadster is not only the most direct technological predecessor to the Roadster, but also served to bring Tesla’s founders together to launch the company.
Tom Gage and his company made 3 of the cars, by hand. The car’s skeleton was a steel space frame, with suspension components, the drivetrain, the batteries, and the suspension bolted to it. Atop all of this sat a lightweight aerodynamic fiberglass body.
The first version was powered by a bunch of normal 12-volt car batteries, specifically Optima Yellow Top sealed lead-acid batteries that have been popular with car enthusiasts. Despite this shortcoming, the car had reasonably good acceleration, top speed, and other characteristics. Range was only 90 miles, which was pretty amazing considering that it was powered by relatively cheap batteries.
Range really was the biggest limiting factor for the car, so Tom Gage decided to build an improved version of the car with lithium-ion batteries, as were already commonly found in laptops. As his project progressed, he met Martin Eberhard, who had a lot of ideas for EVs that Gage says weren’t viable, but they continued discussing EVs and Gage’s project.
When completed, it impressed Eberhard so much that he encouraged Gage to move the car to mass production, but Gage preferred to do prototyping and come up with ideas to sell to other companies. Eberhard then borrowed the tZero for several months and used it as his daily driver. Later, J.B. Straubel became aware of the car and showed it to Elon Musk, and both of these men encouraged Gage to mass produce it. After Gage again said he wasn’t interested in doing that, he put Musk and Straubel in touch with Eberhard.
These men wanted to use the basic design to build the Tesla Roadster, and went on to improve upon it and do just that.
GM’s Impact and EV1, & The ’90s Compliance Cars
Tom Gage and AC Propulsion weren’t new to the electric car scene when they decided to build the tZero. In fact, the company had been building EV components since the late 1980s. The company’s founder, Alan Cocconi, designed and built the controller for GM’s first serious EV prototype, called the Impact, which was revealed at a 1990 auto show. The company then went on to build commercial EV drive units and prototypes for automakers during the 1990s and to present.
Just as the Tesla Roadster kicked off the post-2010 modern EV movement, the Impact did a similar thing for the EVs of the ’90s. Based on a spaceframe (a technology GM had used in a previous production car) and utilizing other technology from GM’s solar racing teams, they managed to build a highly efficient electric car that proved that EVs were at least somewhat viable.
In many ways, it was like the lead-acid versions of the later tZero prototype car. It could go a reasonable distance for city commuters, had decent performance, and could accelerate to speeds of well over 100 miles per hour. It even had plastic and fiberglass body panels and a spaceframe.
Seeing that the car was viable for most driving, and seeing that GM intended to do a production run of the car, the California Air Resources Board decided that the time for EVs on California’s roads had come and instituted a mandate. They knew all cars couldn’t be EVs, but they did expect automakers to make a small percentage of their vehicles electric if they wanted to keep selling gas-powered cars in the state.
GM eventually went to production with the Impact, but named the production car the EV1. Other automakers, with their hands forced by California’s government, followed suit and introduced their own EVs in the late ’90s. The technology slowly improved, with nickel-cadmium battery-powered vehicles to achieve ranges over 100 miles with DC fast charging.
Car companies didn’t really want to build EVs, and successfully sued California to get out of the EV mandate. Oil companies worked behind the scenes to erode support for EV mandates and promote public hostility toward them. Chevron also bought patents for improved nickel-cadmium battery technology and wouldn’t allow anyone to use the technology in cars unless it was a hybrid or otherwise burned gas.
The federal government put their support behind hydrogen fuel cell vehicles, hybrids, and other technologies that weren’t a threat to gas-powered cars. Under pressure from all sides, the California Air Resources Board relented, and scaled back EV mandates. Once this happened, manufacturers stopped production and took back any leased vehicles that they could, despite the fact that owners wanted to keep them. The cars were then crushed, with EV1s left in the Arizona desert to rot.
A lucky few cars escaped total destruction. GM donated some EV1s to universities to use as science projects or museum pieces, and Francis Fold Coppola claims that he hid his EV1 to prevent GM from taking it back. Some EVs by other manufacturers weren’t leased, and had actually been sold to people who wanted to keep them, mostly RAV4 EVs. You can occasionally see these for sale or at a charging station, still working today via their original nickel-cadmium battery packs.
Before automakers (especially GM) chickened out on making EVs, there had been a lot of interest in making cleaner, more efficient vehicles. In Part 3, I’m going to explore the origins of the GM Impact prototype vehicle that kicked off the ’90s EV era (which we know led to the tZero and the Tesla Roadster, and today’s EVs).
Featured image: A GM EV1 that was donated to New Mexico State University (photo by Jennifer Sensiba).
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