Assessing the technical viability of local battery swapping and electric outboard motor retrofitting in Senegal
A blog by Namory Diakhate, a Frontier Tech Hub Implementing Partner.
This post captures learnings from ELEK TEY’s - Electrifying Water Transport for Better Livelihoods - third sprint.
Casamance River, Senegal (Photo taken by Namory Diakhate)
The world is witnessing a rise in electric mobility solutions, and it’s not just happening in developed countries. In Africa, electric vehicles are gaining popularity due to their affordability and environmentally-friendly nature.
In 2022, the UK’s Foreign, Commonwealth and Development Office (FCDO) decided to invest in a pilot project to test the introduction of electric boat motors in Casamance as a cheaper, greener alternative to water transport, in partnership with Jokosun. The pilot project consisted of three sprints: i) mapping the local ecosystem, identifying our pilot user group and understanding their needs; ii) identifying the required technology and designing the sea trials; and iii) testing the technical viability of locally retrofitting conventional motors and exploring options for a battery swapping model.
The road so far
Remember the Market place of ideas with the Frontier Technologies Hub and Ziguinchor’s Chamber of Commerce? Well, a lot has happened since then. Sprint 1 saw us take a closer look at the activities in the area that required the use of outboard motors and assess the distances covered, which would have an impact on the piroguier’s choice of motor. Fishermen, for example, use 40HP engines because of the long distances they usually travel and the heavy loads their pirogues usually carry, whereas pirogues used for tourism (island tours, mangrove excursions, fishing trips, etc.) use less powerful models such as Yamaha 15HP or equivalent. As this is a new technology we opted to test our innovation with tourist guides in the first instance to reduce the risks associated with covering longer distances. Moreover, tourist piroguiers are accustomed to interacting with non-native people, which we anticipated would enable them to feel more comfortable when communicating their experiences of using the new technology and when explaining any adjustments that need to be made, than we would expect if we were to work with deep-sea fishermen. We also intended to take advantage of the fact that these tourist piroguiers are able to talk about the project in their respective circles and influence the conversation.
With our user-group confirmed, we used sprint 2 to test whether an imported electric outboard motor or a retrofitted motor would better respond to the impact we hoped to achieve. By conducting a thorough market survey, we decided to retrofit rather than import pre-made goods due to three overarching reasons:
retrofitted outboards were deemed better-suited for local use because there is a level of familiarity when using the same parts as piroguiers are accustomed to and all parts can be sourced locally (i.e. body, propellers, shafts etc.)
retrofitted outboards were cheaper than imported electric motors, at three times less cost for an imported electric motor of equivalent power
retrofitting would enable knowledge transfer, by creating an opportunity to teach and/or upskill local mechanics on how to retrofit traditional combustion outboards to electric outboards and be able to repair the kits locally, as required, increasing the prospects of positively impacting the sustainability of the solution
Mechanics within our test site of Ziguinchor, Casamance, hold many outboard motors within their premises whilst they wait for their customers to find the resources to pay for repairs. By offering the means to retrofit these old motors, these old casings might be given a second chance and be kept out of the junkyard. The potential of this outcome had a significant impact on our choice of suppliers because it signalled a route through which to contribute to local job creation and livelihoods. It also indicated a more sustainable solution as our target communities might be more likely to adopt our innovation if they are able to have the retrofitting performed locally by their usual mechanic and can rely on them to repair any anticipated faults.
As a result of these decisions, at the end of Sprint 2 we partnered with an Australian supplier, Eclassboats, to provide the electric outboard kits ready for retrofitting.
With suppliers confirmed and the kits ordered and shipped, we started out on our final sprint to test:
Local mechanics’ capability to convert conventional outboard motors into electric motors
The suitability of retrofitted outboard motors in terms of the power, speed, and battery consumption requirements of the target user group
The market potential for electric outboard motors and the local stakeholders that are already in place to support in its growth
Training local mechanics to successfully retrofit boat engines
Mechanics retrofitting electric engines (Photo taken by Namory Diakhate)
The purpose of the training was to equip local mechanics with the skills necessary to convert traditional outboards to electric motors using a kit provided by our partner, Eclassboats. Ensuring that we had mechanics who could carry out retrofits on their own was a crucial part of testing the viability of the technology.
We designed a nine-day training program to teach mechanics how to properly perform a retrofit using old Tohatsu and Hidea casings. We then invited four mechanics to participate in the training, which included a few days of river trials, a day for participants to try retrofitting an engine on their own, and a day for fixing the engine casings we had bought. In reality, something very interesting occurred — after the first day, the mechanics took over, and Ron (one of our Australian partners who was in charge of the training’s technical aspects) watched from a close distance only stepping in if there was something specific he wanted them to understand or if new difficulties arose.
Most of the time, the mechanics didn’t just accept Ron’s statements but instead pushed him with insightful queries and suggestions, demonstrating their genuine interest and buy-in of the innovation. It was important for us to ensure that the mechanics have a deeper understanding of the retrofitting requirements so that they have the ownership necessary to support clients in country to find local solutions, rather than relying on imports.
At the end of the training, our lead mechanic, André, independently retrofitted the 6kW outboard by himself using the Mariner frame we bought. He used the same process that Ron had demonstrated, finishing the task in about four hours.
As a result of watching the mechanics respond to the outboard kits, we are confident that local retrofitting will not only encourage local ownership of the project but will also boost the local economy by creating more opportunities for local mechanics to generate income. Our strategy demonstrated that local mechanics could complete the task just as effectively as their Western counterparts with the appropriate equipment and proper training. Future customers will most likely feel more comfortable knowing the electric outboards were retrofitted locally and that local mechanics are able to repair them if there are any issues in the future.
Piroguiers getting ready for sea trials (Photo taken by Namory Diakhate)
Finding casings that weren’t too expensive but were in fairly good condition proved to be a challenge as we prepared for the training. We purchased old Tohatsu and Hidea casings for the purpose of retrofitting without realising the condition they needed to be in for the retrofit to be carried out. Consequently, we had to spend additional time and resources to rebuild those two casings to meet the necessary functional standard before we could begin the retrofitting.
Through this process we discovered that piroguiers don’t throw away or sell their casing as long as they’re still in working condition, or as long as they have the opportunity to give them a new lease of life by buying a spare part here or a new gear there. This is likely due to the value they place on their motor and the cost of replacing or upgrading it. This makes it almost impossible to give a second life to engines that are ready for the scrap yard, especially when it comes to brands other than Yamaha which are the most commonly used outboard engines in Senegal. We believe that Yamaha are popular because they are heavily subsidised by the National Fishery Ministry. Licensed fishermen only pay 30% of the price of a brand new Yamaha motor for their first purchase. As a result there is a plethora of Yamaha casings and spare parts available locally compared to the Tohatsu, Mariner or Hidea.
Another valuable lesson we learnt was that not all conversion kits would fit a Yamaha casing. Instead a jacking plate is required. The conversion kits we had procured for this experiment could only fit into a Mariner 18, a Tohatsu 20 or Hidea 15. As a result, we will ask Eclassboats to design jacking plates that will fit into Yamaha casings to meet the needs of our user group, and the majority of our future market. As the majority of our initial discussions with Eclassboats centred around power comparisons between the conversion kits and conventional motors, we didn’t anticipate experiencing issues with the placement of the kits inside the casings and a need for different jacking plates.
Sea Trials
After the retrofitting process had been successful, we conducted a second experiment to see if the retrofitted electric motors could perform as well as conventional outboard motors to respond to the needs of piroguiers. We designed a set of 15 sea trials using both engines that would allow us to test their capacities in terms of power, speed and battery consumption. The first two trials were designed around sailing within close radius of the dock to measure the initial reactions of our user group and build their confidence in using the electric motors. The subsequent trials, on the other hand, were designed to replicate a typical tourist piroguier excursion. We gradually reached further destinations, as piroguiers would with conventional motors, and were eventually able to travel as far as 20 kilometres from Ziguinchor on one of the most popular routes for touring boats.
In order to look for irregularities such as a malfunctioning cooling system for the engine, wiring mistakes, or even just water splashes getting into the casings, our initial testing was conducted in a water tank. Then, one at a time, we mounted the engines on our partner’s (Mame Birame’s) boat for an initial excursion close to the quay to observe how the engines handled the water and introduce the piroguier to the electric motors. The 4kW kit was put into a Hieda 15 casing and the 6kW kit was retrofitted into a Tohatsu 20 casing. Mame Birame felt very positive about the 6kW (T20) saying that it can easily be used for their touring activities because its characteristics meet their needs, and the silence it offers is ideal for their excursions, especially in protected marine areas and bird breeding grounds.
Sea Trials (Photo taken by Namory Diakhate)
The speeds and maximum outputs of the two electric motors appeared to be quite satisfactory although the 6kW gave closer performances to the Yamaha 15HP that the piroguiers were accustomed to using.
A typical boat tour usually involves a 30-minute trip inside the mangrove-lined bolongs, giving tourists the chance to enjoy fishing or engage in sightseeing activities to spot dolphins or birds. It might also form part of a larger excursion that involves taking a boat to one location and then hiking or riding to another. During a later sea trial, we were able to reach Elana (20km north) and the Pointe Saint-Georges route (35km west) from Ziguinchor, two of the most popular routes for tourist piroguiers. We, however, decided against trying to reach the Niomoune Islands (five hours by conventional boat north west) because we did not want to take the chance that we would run out of battery on the way back.
During these trials, we monitored batteries and engines in order to gather as much data as we could to be able to compare them to what we already knew about conventional motors. For instance, we saw that the 6kW engine would reach speeds of nearly 14 km/h when it was operating at full capacity and with eight to nine passengers on board. After 90 minutes, the batteries were still at 75%, indicating that they could be used for tours lasting at least 3 hours, which is within their normal operating circuit. Although the 4kW engine has a shorter maximum speed and less power, it has a longer battery life. It has a maximum range of 11 km/h and has a battery life of slightly longer than 4 hours.
One of the main challenges we ran into was that after about 10 minutes of running at full throttle, both engines would systematically shut off for 60 to 90 seconds before restarting when the piroguier gradually increased speed. This is particularly an issue for our use case as there is an open body of water that boats have to cross to reach the mangroves. In order to maximise time within the bolongs and please their customers, the piroguiers would typically sail full throttle to the mangroves and would only slow down once inside. It takes about 20 minutes to cross the river, so at full throttle, our motors would stop twice before we could reach the bolongs.
Mame Birame (in blue) Issa (red and white) (credit photo Namory Diakhate)
Curiously, this does not occur when the piroguier occasionally slows down to give the engine a breather. Trying to understand the underlying cause led us to several potential explanations, one of which is that high amp draw from the motors over an extended period would cause the battery to shut off in order to protect its cells, as an in-built safety measure. In fact, battery data indicated that the amp draw may have exceeded the capacity of the batteries used.
A first step in finding a solution to this issue was to install high thrust propellers which are the most energy efficient propellers available in the industry. This reduces the motor’s amp draw because the structure of the blades has a significant impact on how smoothly the engine operates, which in turn affects how much energy is absorbed when the boat is moving. Therefore, a boat will be lighter and require less energy to move when its propellers are flowing smoothly against the current. We could not find high thrust propellers in the local market so whilst locating it abroad we mounted new propellers with smaller pitches but larger blades resulting in delaying the cutting-off time by 15 to 18 minutes. In addition, we reprogrammed both engines to stabilise amp draw fluctuation and set them at a continuous 50 amps and we will reprogram battery amperage to align the engine’s amp draw to the batteries’ maximum output. Unfortunately we were not able to do that remotely as our batteries do not have a remote control option. Instead, we need to get a pre-programmed key card from the supplier and insert it into the batteries.
Another issue we faced was the uneven consumption across the two batteries. During the first sea trials we noticed that batteries’ percentages were not the same: when one indicated 80%, the other indicated 75%. Whilst we may have used a battery that was not fully charged, we run the risk of relying too heavily on one battery than the other. Moving forward, we intend to rectify this by replacing the two 48v batteries with a single 96-volt battery (see more below).
Despite these challenges, by the end of the sea trials, our tour guide, Mame Birame, was able to operate the engines for several hours without shutting them down by adjusting his usage to occasionally take his hands off the throttle, allowing the amp draw to remain stable and preventing the batteries from cutting off. This minor change demonstrates to us the need to encourage behavioural adjustment alongside introducing the technical changes if piroguiers are to switch to electric motors in the long-term.
Battery swapping
Another crucial test during this sprint was how to set up a smooth and efficient battery swapping mechanism as a better alternative for electric motors to stationary charging. In order to achieve this, we needed to have the greatest degree of certainty regarding factors such as the quality and capacity of the batteries used, their discharge and recharge times, and the transport procedures to be used for battery delivery from the charging facility to the boat. The results from this experiment will be used to establish a pricing structure that is affordable for the piroguiers and quickly profitable for the business.
One of the first things we did when we started this project was to select a reliable battery supplier. We spoke with the French company, Batconnect, with whom we had previous working relationships, to see what type of equipment they could provide. At the time, they were unable to supply a 96- volt battery with all the required safety certifications. As an alternative, they offered to use two 48V batteries, which we agreed to as there were some concerns regarding Senegalese legislation that restricted the importation of 96V batteries. The batteries weigh 45 kg each and initial charging took about 3h30 and was completed with a manufacturer charge of 30%. Subsequent recharges took between 2h30 and 3h depending on how flat the batteries were. Initial testing on the boat confirmed the storage capacity as they measured a 25% energy consumption for a 1h30 trip, indicating that we could sail for three to four hours before the batteries drained, which is enough time to replicate a regular touring trip.
Batteries in front of the water tank test (credit photo Namory Diakhate)
In the course of the battery swapping testing, we were able to assess the capacities and handling of the batteries in a few different scenarios, but there were some challenges as outlined below:
Weight of the batteries: indeed moving around two 45 kg batteries is quite challenging when navigating a busy dock and fitting them on a boat with all the instability of the water. Loading and transporting them from the charging station to the quay required two people at each end of the process.
Number of batteries: Having only two sets of batteries for two motors means we have to charge them after each piroguier returns from his excursion. As a result, we have designed a battery charging model, taking the batteries to charge after pirgoguiers are back from the sea, to be collected the next day for their next excursion.
Distance: We could not replicate the long distance excursions to the island because we did not want to risk fully draining the batteries before we were back in Ziguinchor. This exposed the risk of having a single charging station and relying on the grid to charge. Instead, we will explore the option of strategically-located charging facilities along the river, to enable pick-up and drop-off of batteries en route.
Transport of batteries: the size and weight of the batteries made it impossible for us to transport them by motorbike as only one battery could be supported. Instead we trialled the use of three-wheelers or taxis to transport them from the charging facility to the quay as a round trip. This cost twice the price we would have paid if we had used the motorbike and almost twice the time to transport them as well.
We intend to develop our battery swapping project in response to these factors taking into consideration the difficulties we encountered during this experiment. As a result, our battery swapping model will include:
Delivering the batteries to the piroguiers rather than have them come to us to avoid them the inconvenience and safety risk of transporting and loading heavy batteries by themselves. When the batteries are fully charged, we will have a designated member of the charging hub to assist the technician in loading them onto the tricycle and transporting them to the quay, where the piroguier will exchange them with the empty batteries he used previously.
Having battery stock is a must. Batteries need about three hours to fully charge when empty, which is how we expect them to be when we get them back from the piroguier. In order to avoid having to take the batteries back and charge them while the piroguier is waiting for them, we must have extra sets of batteries fully charged and available for delivery at all times in the charging station.
More than one charging station is required to meet the needs of the battery swap. Our most recent sea trials have shown us that the battery time depends on the engines. The 4kW engine uses fewer batteries than the 6kW engine, on average, and as a result has a longer battery life. The fact remains, however, that if we want to prevent piroguiers from running into issues during a long trip, we either need to give them an extra set of batteries to carry on board or set up a second hub at a strategic location where they can pick up batteries on their journey.
Using solar energy for the battery station. We currently use the grid to charge batteries, but in the long-term we will explore the switch to solar power. This is not only a more environmentally-conscious option, helping us to attract green funds in future, but will enable us to establish charging stations in off-grid locations and support longer journeys.
For the purpose of facilitating the delivery of batteries to piroguiers, we are also considering the use of electric bikes or tricycles. Using electric bikes makes sense for two reasons. The first is that we should refrain from utilising fuel ourselves in our business model because we are an advocate for green energy. As people, organisations, and possible donors will realise that the project is entirely powered by solar energy, it will also serve as good advertising for Jokosun. The second motivation for using a solar bike is because we might be interested in expanding our business offer to other forms of transport in the future, and battery-swapping for motorbikes complements what we are now doing with the outboards.
Market assessment
Our project aims to promote the use of electric motors in the Casamance region of Senegal, where river navigation plays a significant role in daily life. To achieve this, we have taken several steps, including carrying out assessment missions, conducting sea trials, and working with local mechanics to retrofit traditional combustion outboard motors to electric ones.
Transport Boat from the Islands (credit photo Namory Diakhate)
One of the key challenges we have faced is promoting the adoption of electric motors in a region where traditional combustion outboard motors have been the norm for decades. To overcome this challenge, we have begun to explore potential partnerships with local players to distribute and maintain electric motors, maximising their accessibility and sustainability.
By partnering with hotels and tourism agencies, we can increase the visibility and accessibility of electric motors to tourists and locals alike. Electric boat tours can become a popular tourist attraction, and by showcasing the benefits of electric motors, we can help to raise awareness of their potential in the region. Additionally, these partnerships can provide a source of revenue for local businesses, which can help to promote economic development in the region.
Arrangements with local mechanics for motor maintenance and repair can also contribute significantly to the adoption of electric motors. By working with local mechanics to retrofit traditional combustion outboard motors to electric ones, we can promote the transfer of technology and knowledge. This can help to foster local project ownership and increase the adoption of electric motors by local communities.
Moreover, such partnerships can contribute to the wider adoption of electric motors and have a positive impact on the local community. By replacing traditional combustion outboard motors with electric ones, we can reduce air and noise pollution and promote environmental sustainability. This can benefit both the local community and the ecosystem, as electric motors emit zero emissions and are much quieter than traditional combustion engines.
Lessons for Our Business Plan
Jokosun aims to provide a comprehensive package to piroguers, encompassing retrofitting of their outboard motors, installation of the battery swapping mechanism, and battery provision. As a full battery business, we offer battery rental services, as well as our own infrastructure for battery management. This approach significantly reduces the cost that piroguers would otherwise incur if they were to undertake retrofitting and installation themselves. We believe that this will make the switch to electric motors more appealing to our target market and help to promote their widespread use in the Casamance region.
In addition, we plan to explore potential partnerships with hotels, tourism agencies, and local businesses to increase the visibility and accessibility of electric motors to both tourists and locals. By highlighting the benefits of electric motors and promoting their adoption, we hope to contribute to the economic development of the region and reduce air and noise pollution to benefit the local natural ecosystem.