More Data Shows How Two Successful (If Slow) Solar Cannonball Runs Went

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Last Updated on: 14th March 2025, 02:20 am

A year or so ago, I wrote several articles about attempts to cross the United States on nothing but solar power, carried along on or in the vehicle. Since then, the slow pace and even slower release of information about these trips led to me moving on to other things and losing track of them. In this article, I’ll update readers on two successful trips, even if they took a LONG time.

Why This Matters

Today, being able to cross whole continents is something we take for granted, but 100–200 years ago, this wasn’t the case. Before the first transcontinental railroad was completed at Promontory Summit, the fastest ways across the continent were to either go by wagon or bypass it completely by taking a ship around South America. Either options would take weeks at best speed, but usually months. Many people never made the trip, dying along the sides of wagon trails or drowning in the treacherous currents between South America and Antarctica.

Setting records may look like a pointless, macho thing to do, but they lead to progress. The U.S. military’s first attempt to cross a continent was slow and awful, taking weeks, but it led a young military officer named Dwight D. Eisenhower to eventually push for the construction of the Interstate Highway System we can zip along on today. Pushing solar technology like this won’t win anybody any speed awards or even much recognition today, but setting benchmarks to beat can inspire further progress.

The First Known Solar Cannonball

Recently, the Power of Light YouTube channel, run by Joe Kliewer, put out the final episode about the late 2023 journey across the country, along with a map of charging stops and other details.

The trip is well documented, and has time lapses of the whole run, showing that it was a legitimate record. But nobody was ever likely to dispute this record because it took almost two months! The trip started on October 3, 2023, and lasted until November 29th. Along the way, he stopped at campgrounds at national and state parks, nice property owners’ lands, and even barren desert BLM land in New Mexico to set up dozens of 100-watt solar panels. Charging stops took days at a time, and sometimes even longer when rainy weather would stick around too long.

To say that this is a trip that most people would never repeat would be an understatement. Needing to find places to charge took precedence over basically everything, including basic comforts. It would be nice if every town had a motel with a big lot next to it that allowed people to set up a portable solar array, but that just doesn’t exist and probably never will because there’s just no demand for it.

The Second Run Was Faster, But Made Other Big Compromises

In mid-2024, another team made the trip across America in just under two weeks. But the vehicle wasn’t something most people would consider taking such a trip in. Instead of taking a Tesla vehicle at speeds one would consider to be highway speeds, this team took something that straddles the line between e-bike and car. If anything, it resembles the solar-powered cars that students have raced for decades. However, the Sun Strider was registered in Michigan as a motorcycle, so that’s close enough for a record.

Traveling at speeds of up to 35 miles per hour, all of the solar panels were mounted to the vehicle itself, and they’d keep up with the motor in many cases. The vehicle had a 2.9 kWh battery pack and two 3.2 horsepower motors that didn’t survive the trip without needing changed out. High temperatures were hard on the electronics and the drivers, as there was no air conditioning.

Where Will It Go From Here?

At present, it seems reasonable to be pessimistic about the future of onboard solar power for vehicles. Two weeks to cross the country? On something that’s less pleasant to ride than a bicycle? Or two months in a normal car? Who wants to do that?

But we have to remember that EVs, powered by the grid, were once on such dismal timetables. When the first attempts were made to do this in 1968, it took over 210 hours, which would be over two weeks if you were to drive 12 hours per day. The EVs of the time were all conversions with old battery technology, and there was no fast charging. It wasn’t until the 2010s that EV technology improved and charging stations that could fill ‘er up in a half hour came out and drastically improved EV highway travel!

Solar technology has also come a long way in that time. The first solar cells were only experimental, and produced little power. Efficiency went from almost zero to capturing almost a third of the available solar energy. Looking forward, 40% efficiency is already in the pipeline, with 50–60% not considered impossible. Researchers think that as much as 90% of sunlight could be converted to electricity, but that’s not a sure bet at this point. Even doubling the efficiency of solar panels would double the speed of solar cars on such cross-continent trips.

There’s also no rule that says solar power has to always live on the car. The Cannonball Sun challenge (started by the second team discussed above) only dictates that the vehicle be powered only by sunlight, be registered, and follow the rules of the road. Solar EV charging infrastructure can certainly be part of the solution for EV charging infrastructure, and if enough solar-only stations are deployed, it could give solar Cannonballers a big boost in times. This wouldn’t be easy for DC fast charging (a big solar farm would be needed), but it’s within the realm of the possible with battery storage.

None of this is going to happen overnight, of course, but neither did EV technology or solar technology. Having the Cannonball Sun as a benchmark for solar transportation can serve as a useful tool for tracking the improvement for such technology in the future.

Featured image: a screenshot from the first solar Cannonball run.