The trip was a great success—we now have a much clearer view of the task ahead, and enthusiastic support from the NGO, hospital and health authorities in Zimbabwe.

One of the key outcomes of the trip is a change of name for the project. Nobody wants to travel in an ambulance, and so the vehicle will be called the ‘African Solar Taxi’.

The other major outcome is that we now have GPS paths and lots of video for the roads we will be using. Many of the roads are dirt tracks. Most of the bitumen roads have not been maintained since they were built about 30 years ago; they are wide enough for one car only, and have potholes and rough edges. This means that we will have to build a vehicle that is both lightweight and robust, with four wheels.

You can find out more, and track our progress, on our new blog: africansolartaxi.com.

Zimbabwe has one of the highest maternal death rates in the world. One of the factors that contributes to the high maternal death rate is the difficulty that expecting mothers have in getting from rural villages to health care facilities such as delivery hospitals. Almost half of the births in the Mashonaland Central region are delivered at home without formal medical assistance.

We are currently working to design, develop and demonstrate a system for transporting expecting mothers from rural villages to health care facilities. The system will comprise vehicles that can be used to transport women to and from health care facilities, and a system for scheduling and managing the vehicles to maximise their effectiveness.

Because of the high cost and low availability of fuel or electricity to power vehicles, the vehicles will be powered by human and solar power. Bicycles with trailers are being used in some parts of Africa for patient transport, but speed and range are limited by the endurance of the rider. We will investigate the use of electrically-assisted cargo bikes with trailers, or custom designed low-energy vehicles based on readily-available components, with solar panels for recharging batteries.

The key vehicle requirements are:

• vehicles will service villages within 30 km of a health care facility, and travel up to 80 km per day

• vehicles must transport the rider, the patient and an accompanying friend

• vehicles must be capable of travelling on unsealed roads and tracks at speeds up to 30 km/h.

If you are interested in being involved in this project, contact Andrew: zimbabwe.bicycle.ambulance@gmail.com

Generators on the wheels is not a bad idea. The electric motors used in most electric and hybrid cars can act as motors converting electrical power to mechanical power, or as generators converting mechanical power to electrical power. Working as a generator, the motor can convert the kinetic (movement) energy of the car into electrical energy, and this energy can be used to partly recharge the battery. But converting the kinetic energy of the car to electrical energy slows the car. It is called regenerative braking, and the braking force that can be achieved is about the same as the driving force that can be achieved by converting electricity to motion.

Regenerative braking cannot convert all of the kinetic energy of the car into electrical energy—some of the energy is dissipated by resistance forces in the tyres and bearings and by aerodynamic drag, and some is dissipated as heat in the motor/generator and in the electronic controllers. But some of the kinetic energy can be converted to electricity and stored for later use—which is better than occurs with normal friction braking, where all of the kinetic energy is dissipated and none of it can be recovered.

But the proponents of generators on the wheels often want to go beyond regenerative braking to generate electricity without slowing the car. Not necessarily perpetual motion, where the generators generate more than enough electricity to power the motors, but enough to reduce the power required from the battery.

It doesn’t work—at least, not in our universe.

To see why it doesn’t work, try writing power values in each of the empty boxes in the diagram below. Suppose the car is travelling on a flat road at constant speed, so the power values are not changing. The total power into the motor must be the same as the total power out of the motor, and the total power into the generator must be the same as the total power out of the generator. It is like Power Sodoku—everything has to add up.

Instructions:

1. Write in the power required for propulsion. This is the power required to overcome rolling resistance and aerodynamic drag. Trev uses about 4000 W at 70-80 km/h.
2. Write in the motor losses. Losses in an electric drive system are about 10% of the propulsion power.
3. Write in how much power will be transferred from the motor to the generator, and generator losses (about 10% of the power into the generator).
4. Calculate the ‘battery out’ power and the ‘battery in’ power.

The total energy from the battery is (battery out – battery in). What do you have to do to minimise (battery out – battery in)?

First up, we need to get Trev re-registered in South Australia. When we registered prior to departing for Zero Race, the assessor said that we’d need to complete a lane-change test prior to driving on Australian streets again. We’ve upgraded the front suspension over recent weeks and we undertook a successful swerve test last week, so we hope to be back on the road very soon.

Our next plan is to use Trev for urban commuting, which after all is what it was originally designed to do. We plan to install data loggers in the car to record energy use, then share the car amongst team members to commute and use for their everyday driving, one week each.

With Trev out and about on the streets of Adelaide, we expect to get a lot interest in the car once again, which will give us the opportunity to share our story about Zero Race, and more importantly, to demonstrate that if a  little green car can drive around the world in 80 days, it is also more than capable of commuting to and from work.

Lessons learnt

Our aim in building Trev, and in driving around the world in Zero Race, was to demonstrate that it is possible to build practical vehicles that use clean energy, and use a lot less energy than conventional cars.  We have driven from Geneva to Shanghai, from Vancouver to Cancun, and from Casablanca back to Geneva. We have driven across deserts and across mountains, through remote rural areas and through some of the world’s largest cities, on all types of roads, in all types of weather. The energy cost of the journey was less than $400 worth of electricity generated from a wind farm. The net emissions were zero.

Australians are amongst the world’s highest emitters of CO2, per person. Our energy use is high, and we generate almost all of that energy from fossil fuels. Over the next 40 years we need to reduce our per-capita emissions by 95%. To achieve this, we need vehicles like Trev.

Over the next few days will will give Trev a good clean, pack it into a crate, and ship it back to Australia. When it gets back, we will continue refining it to make it more comfortable (it is quiet outside the car, but not so quiet inside the car), more efficient (there are still some efficiency improvements we can make to the motor controller), and easier to build. It is not yet ready for the showroom. But it has shown what is possible, and hopefully will make people think about how they will get around in a future without cheap oil and with an atmosphere that cannot take any more CO2.

Trev-heads Chris and Alexandra are in Morocco. They have unpacked Trev, checked over the car, topped up the battery, and driven in the chaotic Casablanca traffic. Apparently they are not the only drivers unsure about which way to go around round-abouts.

Today they will drive to Rabat, the first stage of the final leg through Morocco, Spain, France and Switzerland to Geneva—the end of the first around-the-world Zero Race.

Zero Race arrives in Cancun

Our arrival completes the second leg of the Zero Emissions Race around the world and more than 23,000 km of driving since leaving Geneva in August.

Trev has been driven through North America from Vancouver to Cancun by Nick and Andrew, who have put in an enormous effort to overcome challenges such as reliable charging access, long driving days, cold weather, troubles with Trev’s motor controller, Mexican speed bumps and potholes up to half a metre across and 30 cm deep! A very tired Andrew and Nick have now been joined in Cancun by Peter, and the rest of Team Trev are hugely proud of their efforts.

Trev will help spread the message in Cancun that we need to be developing alternative means of travel with low carbon emissions and low energy use. In a few days’ time we will put Trev on a ship back to Europe for the final leg of Zero Race, arriving back at the start line at the UN headquarters in Geneva in late January.

There have been many highlights of the trip through North America. We will  write about these in future blog posts, coming soon.

We are very grateful for the ongoing support of our sponsors who have helped us get this far: UniSA, Google Australia, Galaxy Resources, EcoGreen Electrical, Design Ecology, ABN Newswire and Catcon.

Nick and Andrew had arrived in Vancouver carrying spare parts from Australia: a new rear wheel, spare shock absorbers, software updates and various spare circuit boards. They had a couple of days to inspect for any damage to Trev from the long drive from Geneva to Shanghai, to perform some technical upgrades, to get the official paperwork sorted for our North American drive and to sort out an array of electrical sockets  and chargers for the different power outlets we anticipate in North America. Busy busy.

Athlete's Village, Vancouver (courtesy of Zero Race)

The North American leg commenced at the Athlete’s Village in Vancouver on Friday 12th November, and headed south to Seattle, where we participated in the Seattle International Motor Show. From there it was down to Portland in Oregon, driving through beautiful, thickly forested landscapes. It has been wet and misty, which isn’t ideal weather for electric vehicles, but so far so good.

Zero Race vehicles with the eVaro EV (courtesy of Zero Race)

Trev at the Seattle International Motor Show (courtesy of Zero Race)

We have been overwhelmed with the  enthusiasm from supporters and hosts along the way so far in North America. It’s great being able to speak the same language (unlike most of the first leg of Zero Race), and there have been electric vehicle associations who have been very generous to the Zero Race teams. Vancouver, Seattle and Portland are at the forefront of sustainable transport innovation, and it was great learning about the electric vehicle charging facilities they’re installing in advance of the first wave of mass produced electric vehicles, which are just starting to appear on the streets.

Andrew, our newest Team Trev Zero Race driver (courtesy of Zero Race)