It takes some gall to try and change the way people move through a city. Then again, it takes some gall to sail solo around the world on a boat you built yourself, including passage through the treacherous waters of Patagonia. An adventurous spirit landed German-born Alexander Wopper in the southern Chilean city of Valdivia 30 years ago, and it's that same spirit that emboldened him to breathe new life into the underused river that cuts right through its center. At his boatyard tucked away in the forest, on the edge of this waterway as it snakes its way out toward the Pacific Ocean, we sat down with Wopper to talk sustainable transport, earthquakes and inspiring a new generation of green-minded entrepreneurs.

"When I was young I was a very smart, intelligent and happy guy," says Wopper. "I had long hair and would play my guitar every day. And then I decided to sail around the world for four years. Four years on my own sailboat that I built with my own hands. After sailing around Cape Horn, I spent a half-year in the Patagonian channels and I fell in love with this country. I said, 'It's paradise.'"

At the time, the military dictatorship of Augusto Pinochet ruled over Chile. Tales of his oppressive and ruthless regime would have been enough to deter most travellers, but for Wopper it was a source of intrigue.

"The military government was still in power so it scared all the foreigners away, but I came here because I was interested. By profession I am a political scientist, so I'm a certified liar," he says with a smile. "So I was very interested to see this country, and also because of the incredible stories I'd heard about Patagonia. So I spent time sailing down there, and then when I arrived in Valdivia I was just 30 years old, so I decided to stay here and do something. And the best thing to do was to build boats."

Alwoplast is a 30-year boatbuilding business that today exports million-dollar catamarans to customers all over the world Nick Lavars/New Atlas

And so Alwoplast was born, a 30-year boatbuilding business that today exports million-dollar catamarans to customers all over the world. Building up a good reputation in the nautical world and the profitable business that followed is what has allowed Wopper to indulge in more environmental pursuits ... like building solar-powered water taxis. But to really understand the story of Wopper and his sun-powered vessels, you actually have to go back more than 500 years.

The city of Valdivia sits around 15 km (9 mi) inland from Chile's west coast, where a whole lot of water is funnelled down from the Andes through the Calle Calle and Cruces rivers, before being carried out to sea along the river Valdivia. By virtue of these water networks, the native Huilliche-Mapuche people settled where downtown Valdivia stands today, and the village Ainil became an important trade hub prior to the arrival of the Spanish in the 1500s. The conquistadors carried on this tradition, as did the Germans when they colonized Valdivia in the 1800s. And then disaster struck.

The Great Chilean earthquake of 1960, the most powerful earthquake ever recorded, devastated Valdivia. It destroyed thousands of homes and lives, triggered landslides, submerged a lot of land and set off tsunamis that were felt as far away as Japan and Hawaii. One consequence of this was that one of southern Chile's most important trade routes was no longer navigable.

Alex Wopper at his boatyard in Valdivia, Chile Nick Lavars/New Atlas

"Before the river was deep and narrow, and now the river is flat and wide. The earth sank, I think more than two meters, this entire area here is a result of the earthquake," Wopper explains, gesturing around the boatyard that sits well below the level of the road running along the northern edge of the property. "Before, big ocean freighters came up to Valdivia, you see it in the old pictures, they would unload right downtown. It was the base of the old native Indian settlements 400 or 500 years ago, then the Spanish, then the Germans when they arrived. It was always very important this river, it was the main avenue here in town. But after the earthquake, the people forgot that completely and became kind of scared by it."

The Valdivian landscape is a beautiful one. Thick, towering forests coat every visible inch of the surrounding hillsides, which roll on into the region's ample rivers and wetlands that brim with birdlife. The government today spends a lot of money dredging the Valdivia River to maintain a navigable depth, and as it passes through the town center, it plays host to a shoreline fish market, a sizable gathering of water-tour operators and rowing teams honing their craft.

The Valdivia River, with a fish market and tour operators populating the boulevard on the left Nick Lavars/New Atlas

How vibrant the river already is, well, that's probably a matter of perspective. But in Wopper's view, such a waterway has the potential to be much, much more. "Imagine in the US or Europe, a river like that would be full of restaurants, sports clubs, rent-a-boat services, but here there is nothing." So Wopper began to explore ways that he might be able to make a difference.

"The project started in 2010 as a way to return the importance to the river, the importance that it truly has in this city, in my opinion," he explains. "Because after the earthquake in 1960, they all thought the river is basically a problem, it cuts the city in half. But I thought, it is a gift from God, it's what makes Valdivia different from Temuco or Osorno or the other cities around us, having this river as the central avenue right in the middle of the town. So how about getting rid of some old buses, and transporting people on the river, on our main highway? But do it in an efficient and environmentally sustainable way?".

"When I was young I was a very smart, intelligent and happy guy with long hair." Nick Lavars/New Atlas

Wopper's big idea hinged on using the city's natural resources, its abundant waterways and energy from the sun, to propel residents throughout their daily business. So he took around US$1.5 million from his successful catamaran business and used it to develop a different kind of vessel: 20-passenger watercraft running on silent 48 V electric motors that draw on 2 kW of solar power from photovoltaic arrays on the roof. This undertaking would present new kinds of engineering challenges.

"The hull shape, that's number one," he explains. "To get a very, very efficient hull shape with minimum resistance so you can basically push it with your thumb through the water. That also means you have to pick a construction system and design it well to make it as light as possible, because every extra pound in the boat needs some energy to move it."

A solar-powered water taxi in action Nick Lavars/New Atlas

After adding the finishing touches to his first water taxis, Wopper soon realized that they would need some sort of office to handle the administration side of things. So in keeping with the sustainable spirit of the venture, he and his team began work on what would become "Barrio Flotante" (literal translation: "floating neighborhood").

Opened in 2013, this small floating village tacked onto Valdivia's downtown riverside boulevard acts as a ticket office for Wopper's water taxis, along with an on-water restaurant and bar. It produces its own power through rooftop solar and purifies 14,000 L (3,700 gal) of river water every day through a bacterial treatment process.

"We have about 1,000 visitors every day in summer, so people go there because it's unique in South America, there's nothing else like it," says Wopper. "And from what I have heard from my European friends, there is nothing in Germany or Europe like it, and I haven't heard of anything in the States like it either. It really is a unique thing."

The view inside the on-water restaurant at Barrio Flotante Nick Lavars/New Atlas

On a nice summer's day, visitors to the Barrio Flotante can take a tour up and down the river in Wopper's water taxis, or just sit and relax on the water with a beer, coffee or bite to eat. Encouraging people to enjoy the river in this way is what it was all about for Wopper, but at the same time, a big part of his vision remains unfulfilled.

"Our idea was, with the previous government, to get rid of at least 30, 40 or 50 of the old city buses, which 400 or 500 people use to come to Valdivia every day to do errands, to go to the bank, things like that," Wopper explains. "The idea was to pick them up at the station, for example, and bring them to the main dock, or to the university, or to the other side of the river and establish a fixed line where you're going to know every 10 minutes that a boat is coming. And we had plans for bigger units, for 60, 80 or 100 passengers."

The previous government went ahead and financed a couple of public docks for the service. They were built, but they were never certified by the navy, never got the appropriate permits from the municipality and they never got the necessary insurance for public use. So Wopper's water taxis operate in a bit of a grey area at the moment. The navy turns a blind eye while they run people from one side of the river to the other for $1 a pop, and they're free to take tourists around the area. But for now, Wopper's grand plans for a sustainable, water-based public transport service remain grounded by bureaucracy.

"So it was done, but the government, as it quite often is, was not very efficient and it's still in a grey area legally, these docks, so we cannot officially advertise and move lots of people around," he explains.

Water taxis outside Barrio Flotante Nick Lavars/New Atlas

Alwoplast has won considerable recognition for this work, including a string of awards and a listing as one of Chile's most innovative companies in a 2014 publication titled Hecho en Chile. President Michele Bachelet cut the ribbon at the opening of Barrio Flotante, and politicians and ministers have lunches and special meetings there today. "They love this environment, they realize now that the river is something very important. It's an asset for Valdivia, not a problem." But still, when asked if this would translate into enough governmental muster to roll out his imagined transport system, he seems defeated.

"You need somebody who pushes these things all the time, and I thought last year when we got these awards that it would help a little bit, but just nothing," he says. "I mean they're all very proud and want pictures with my face and to say 'Hey, look, this is what we do in Valdivia!' but there is no real support from government."

Is that frustrating?

"I'm a foreigner in this country and if they don't walk with me at the same pace, if they want to do it their way it's perfectly fine, I have no right to push them," he says. "If they decide to go slowly or do nothing then I have to accept that. I did my part, I contributed because I like the country very much, and I feel like I have to do something, to give something back. But if they prefer to do it at a different pace, then it's at a different pace.

Wopper's water taxi service may have hit a stumbling block, but he feels their presence on the water alongside the Barrio Flotante is already starting to open up the river's appeal to the local community.

Stand-up paddlers warm up outside Barrio Flotante Nick Lavars/New Atlas

"The restaurant is always full, people love to sit out on the river and have their beer or coffee in the evening, they like the environment," he says. "We started a stand-up paddle board club. This was completely unknown before, now there is a little training facility there and we've got a guy that goes in international competition. So people realize you don't have to be a millionaire, you buy a stand-up paddle board, or something that rows, something that floats, and you enjoy the river."

Wopper's solar-powered vessels have generated quite a bit of interest from abroad, with enquires coming in from Europe, the Mediterranean and the Caribbean. And he believes that they could provide an ideal transport solution for tourist resorts in certain parts of the world.

"Take a typical situation in Polynesia, in the Pacific," he explains. "All these airstrips are on the outer reefs, and then they have to bring their guests from the airport on the outer reef to the main island where they have their hotels. And picking up people in a solar boat? It generates a different impression immediately. Imagine you are getting out of the airplane and instead of a smelly, loud diesel boat, you go in a completely silent electric boat. Yes we get quite a few enquiries from Polynesia."

The might be plenty of interest coming in, but there is little interest going back the other way. Wopper's workshop is large, with three big sheds that handle every last production detail of his million-dollar catamarans, from the huge foils and an advanced drive-by-wire system right down to the metal mounts for the kitchen drawers. But it's not large enough.

A worker at Wopper's boatyard in Valdivia, Chile Nick Lavars/New Atlas

"We have moulds for them, so we could industrialize the production of these boats, but we do no advertising, we do nothing because we are so busy with our big catamarans, our export boats, so we just don't have the time or the facilities for a serious production run," he says. "With these smaller boats, we are talking about a $100,000 boat and not a million-dollar boat, so it's only a business when you're talking volumes, so this means you have to build 20 or 30 a year. There is interest, but it would mean I have to stop my production of bigger boats and dedicate two or three sheds to the production."

So for the time being, Wopper's water taxis playing a meaningful part in Valdivia's public transport, or any other city's for the matter, seems out of the question. But all is not lost. Valdivia is a university town, and changing perceptions and opening up possibilities for the city's youth was a big part of why he embarked on the journey. It's too early to tell what kind of effect it will have on the city's next generation for thinkers, but with the bright yellow boats scooting around and a floating, solar-powered restaurant, there's plenty of food for thought.

"It's an inspiration for all the young people in Valdivia," he says. "For the students to innovate, to try and become entrepreneurs, to try and start their own businesses, and accept environmental issues and be kind to Mother Nature. We have only one globe, there are no spare parts here."