South African company launches solar-powered electric boats with unlimited range

South African electric vehicle (EV) maker Thula Solutions has developed an electric powertrain for boats, ideally suited for quieter river cruise safaris.

Thula Solutions previously developed its Electric Safari Vehicle (ESV) for silent game drives.

The ESV is currently open for reservations and, according to the company’s latest update, will enter production in the fourth quarter of 2024.

Thula Solutions founder and CEO Gary Davies believes that in the next two to four years, South Africa’s premier game lodges and many self-driving tourists will all use electric vehicles to view wildlife.

The company is now taking its product offering beyond ground-based vehicles.

Thula Solutions general manager Guy Tatham told MyBroadband the company’s entire team was passionate about boating, so they were always particularly interested in using an EV powertrain on a boat.

Tatham said opportunity came knocking when the Chobe Game Lodge in Botswana reached out to collaborate and update its existing electric boats.

The initial development of the power train took considerable time but through its partnership with ePropulsion, which makes electric motors for boats, it managed to create a compelling solution.

“We are specifically targeting the ecotourism market and highlighting the impact on the environment as well as the enhanced experience, both of which are key marketing points that the lodges and ecotourism sector can use to differentiate themselves in the market,” Tatham said.

“The predominant markets at this stage would be the Okavango Delta and the Zambezi River. However, it is not limited to those areas. The boats can be used anywhere there is water.”

Tatham explained there were several benefits of using electric powertrains on boats rather than conventional fuel-powered engines.

Firstly, the boats can be charged up sustainably with solar power, allowing for a self-sufficient system without the need to transport fuel to customers’ premises.

“It is possible to have zero fuel expenses and run the boat at no additional cost,” Tatham said. 

“We currently have a boat operating at Chobe Game Lodge that has solar panels on the roof and has been operating completely independently for the last two months,” Tatham said.

In this configuration, the boats effectively have unlimited range.

Quiet and emission-free operation

Secondly, as is the case with the Thula ESV, the powertrain’s motors make barely any noise, allowing for a much quieter safari experience.

“Being able to cruise along a riverbank watching a herd of elephants quench their thirst and to be able to hear their low rumbling communications between the herd as well as the birds in the trees truly is something that needs to be experienced in person to get a real grasp of how special it is,” Tatham said.

The electric motors also have zero emissions or pollutants, which can be a significant issue with fuel-based boat motors.

“Outboard motors discharge a lot of unburnt fuel and sometimes oil into the water behind the motor,” Tatham said.

“These can be incredibly harmful to the fauna and flora in these waterways and can have serious impacts across the whole ecosystem.”

“Not to mention that there is no smell of the fumes that come from the motor.”

The boats also have a lower operating cost, as their motors have fewer moving parts than petrol or diesel models, requiring much less maintenance.

Below is a video showing how quietly the powertrain’s electric motors run at cruising speeds.

Retrofits in one or two days

Tatham said although the initial development of the software and componentry for the powertrain took some time, it can now complete an installation in a day to or two.

“It depends on the modifications to the actual boat that may be needed,” Tatham explained. “This is probably the largest challenge.”

“When it comes to cars, retrofitting and modifying an existing vehicle was not feasible and wouldn’t have worked out in the long term.”

“However, this is the standard in the boating industry. You commonly swap out the drive train for your boat over time and keep your existing hull.”

Among the modifications that could be required are adjustments to the mounts for the actual motor to ensure the correct fit, placement, and mounting of the battery box.

Because of the latter’s significant weight, weight distribution is something that needs careful consideration.

Tatham said Thula Solutions was working directly with some boat manufacturers to design a purpose-built hull that perfectly accommodates the battery housing and all related components into one neat package.

Regarding battery packs, the company generally uses one of two configurations depending on the customer’s needs and the boat’s compatibility.

The first is a single 28kWh pack, while the second is a dual 20kWh configuration providing 40kWh capacity.

ePropulsion’s X20 and X40 motors provide 20kW or 40kW of peak output, respectively.

The bigger X40 has achieved speeds of 40km/h on an aluminium boat but is limited to roughly 13km/h on larger, dual-pontoon boats due to the bow wave caused by its hull shape.

Estimated range without embedded solar

The motors can typically travel between 1km and 2.5km for every kWh in the battery packs.

At the more typical safari cruising speeds of between 5km/h and 10km/h, a 10km boat trip will only consume about 10% of the 40kWh battery pack.

That means it will be good to cruise for roughly 100km on a single charge, without additional solar power flowing into the packs.

At top speeds of 40km/h on the 28kWh battery, a boat would be able to cover around 28km.

Another important factor to consider is the mounting of relevant charging infrastructure and distribution boards on the shoreline for boats that don’t have rooftop generation.

The battery packs are recharged with AC chargers, with outputs up to 3.3kW for single-phase power and 10kW for triple-phase supplies.