On solar safari in the Serengeti: challenges and opportunities for the energy transition

The roads surrounding Kilimanjaro airport are lined with solar-powered led-lights, but by the time it’s midnight already half of them have died. Some keep switching on and off at random, most probably due to lack of power supply. Since the batteries are poured in concrete to discourage theft, they’re equally hard to repair or replace. It’s not a local issue, but familiar sight in Africa.

On solar safari

After only a short night the sun gets up at half past six and a bustling morning guides us to Karibu-Kilifair, the biggest road show for the tourism industry in East Africa, where the showpiece is a safari vehicle converted from diesel to electricity. The first in Tanzania, at least so we’re told. According to a representative, maintenance costs for regular land cruisers easily run up to $1000 a month, partly due to enormous distances they cover for collecting fuel, but so far the total expense on spare parts for the handful of operational solar prototypes is only $1 a year. While these numbers may be exaggerated, the constant crowd around the demo vehicle indicates huge interest.

Shocking conditions

Still, it’s quite a challenge to design an energy storage system for electric four-wheel-drives, that’s robust enough to withstand a lifetime of shaking and shocking on the bumpy dirt roads, while durable enough to hold up in the harsh conditions of high temperatures, high humidity and iron rich dust. Building it is one thing, charging it quite another in off-grid and expansive National Parks, let alone fast and frequent enough to prevent detours, minimise delays and keep passengers on the move. Yet all these problems are perceived as opportunities by the local entrepreneurs in tourism and tech. The air at the exhibition is static with inspiration and ideas.

Plenty sun – and potholes

If the energy transition can happen anywhere it’s here in Tanzania, just south of the equator, where the sun is omnipresent and the grid most certainly not. Already numerous small solar systems are in use throughout the country, mostly for powering lights and heating water, but scaling them up to larger installations is still relatively new and hard. It’s why we’re here, to support our local dealer Gadgetronix in a their ground breaking endeavour to run a luxury tourist resort in the middle of the Serengeti entirely on solar electricity.

Shaken, not stirred

The next day we board a tiny Cessna that takes us up to 12.500 feet of altitude, as the pilot assures us ‘we don’t want to run into any mountains’ and carries us for an hour across a variety of increasingly deserted landscapes to eventually land at Seronera, a tiny airport consisting of one building and a fire truck. As soon as we continue our trip by car we’re greeted by impala and baboons before we experience at first hand (and bottom) the tough circumstances these vehicles are subject to. The roads are covered with washboard ripples caused by the uniform bouncing of countless speeding wheels. Shaken but not stirred, we pass herds of gazelle, scattering zebra and a handful of giraffes until we round a hill and ascend it all the way to the top. There we find a Lahia: a brand-new luxury tourist lodge with a magnificent panoramic view a splendid infinity pool.

Jaw-dropping craftsmanship on diesel

Construction has been in full swing since November to literally build this whole place from scratch, which is an astounding feat, especially when considering from how far they bring in all the people, equipment and materials. A crew of two hundred men have set up camp to manufacture everything by hand, from fitting the rafters, to welding the beds, carpeting the furniture and sewing the drapes. It’s an awe-inspiring demonstration of craftsmanship nearly extinct in the west.

Tourist accommodations like these typically run on diesel generators, placed conveniently out of sight and out of sound, but nonetheless consuming hundreds of liters of fuel each day, guzzling oil and exhausting toxic fumes to the breath-taking surroundings and awe-inspiring animals already in danger of going extinct. Moreover, the continuous absorption of energy drains our planet’s limited supply of fossil fuels and last but not least the lodge owners’ bank accounts.

Saving water in a leaky bucket

Many resorts make use of solar energy to power at least some of their low energy equipment, but most bigger systems squeak and crack under heftier loads, which leads to complaints, frustration and improvised emergency solution that only add to the costs. Around here it’s still common to store energy in traditional lead-acid batteries, which compares to saving water in a leaky bucket that you can only fill and empty through a straw. Charge too fast, consume too quickly or deplete too far and they will heat, swell or leak. With heavy usage in demanding situations they require regular maintenance and typically last little longer than a few years. While these disadvantages may be overcome by being extremely cautious, their size and weight is not. Powering an upscale tourist resort like Lahia would require over nine tons of lead-acid batteries.

(Dis)charging through a firehose

It’s why we brought 20 MG lithium-ion High Energy batteries, extremely compact, highly efficient and with a total capacity of 150 kWh, while weighing ‘only’ 900 kg. These are more like the equivalent of titanium vessels you can fill and empty through a firehose. They are able to absorb and release an enormous amount of power in a very short time and feature an impressive cycle life. An added layer of electronics and smart software makes them easy to install and maintain. Because MG’s energy systems are frequently used in marine applications, the batteries are tested extensively for extreme conditions and comply with the highest safety standards.

Redundant energy supply

Over the past week we’ve supported the local crew in commissioning the installation. During the day a solar plant of nearly 500 panels harvests solar energy, inverted by 4 Fronius and 14 Victron MPPT’s before it flows through a grid created by 9 Victron Quattro’s to charge the batteries and, when there’s a surplus, power the resort. A Victron Venus GX allows us to remotely monitor the situation, day and night. The energy system is set up redundantly, which means each of the 5 MG low voltage masters is connected with 4 MG HE modules as an independent unit, to make sure the others keep on working even in the unlikely event one battery should fail. This way the entire lodge runs on solar electricity, from the water pumps to the swimming pool and the chandeliers in the dining room to the bedside table lamps, long after the sun sets on the Serengeti.

Side by side towards a common goal

It’s a steep learning curve to bridge the gap and cross the barriers between each other’s language, expertise, logistics, planning and customs, but side by side we work towards a common goal. After a couple of long days and short nights we can finally switch the giant diesel generator off and hear the sounds of all the animals around us on a dark safari night. In the comforting hum of a smoothly running power room we set up all the stools and crates that we can muster, to share some words of wisdom, while we celebrate our landmark achievement with soda and cake. ‘Hongera sana’ it reads in sweet letters, which is Swahili for ‘Many congratulations’. It’s done. Lahia is the first tourist lodge in the Serengeti to run entirely on solar electricity.

Stroopwafels and sharp observations

On your last day we depart with stroopwafels and heartfelt hugs before the Cessna flies us back to Arusha where we provide a technical training for anyone who’s interested in working with MG. We’re impressed with the warm welcome and deep interest from local engineers, which lead us through an animated and interesting discussion, that educates us all. Even an offered break is skipped for just a little bit more time to ask sharp questions on best practices and theory. If it weren’t for our scheduled flight, we would have enjoyed staying much longer getting to know our new acquaintances. But a car is ready to drive us through the early evening back to Kilimanjaro airport. Most of the lights that lead our way are burning, bright and uninterrupted, others not yet.

First resort in the Serengeti to run entirely on solar electricity with MG batteries

No more diesel generators burning hundreds of liters of fuel a day, polluting the precious nature in this National Park. Lahia lodge is powered by the sun.

Preserving Venice by boarding a hybrid vaporetto with MG’s batteries

Water taxi’s are a threat to the cultural heritage of Venice. Enter Liuto: a hybrid vaporetto that generates less waves and less emission.

Sealegs charges into the future with amphibious craft on renewable energy

Due to the latest battery and motor technology the electric E4 runs 60% quieter compared to conventional models, but 33% faster and 50% more powerful.

Loodswezen saves weight by replacing lead acid battery banks by MG’s High Power alternative

Tenders used for helping sea-going ships enter and exit their ports rely on MG’s system: enough power to start the engines, yet only a third of the weight.

Silent 55 sails free at sea with solar power and storage by MG

The cruising catamaran relies nearly entirely on solar energy. No toxic exhaust, no noise from generators and no excessive vibrations from diesel engines.

Windcat Workboat sets a new standard for efficiency with batteries by MG

To meet energy reduction goals the newest vessel is supplied with MG batteries. This results in high performance, low fuel consumption and low emissions.

Pagani’s fast cruiser Mister A is powered by MG’s batteries

Aldo Pagini’s Mister A is everything you might imagine when you think of a fast cruiser: a 20-meter long sailing yacht that delivers top performance in great comfort. It even steered to victory in the Maxi Yacht Rolex Cup. So MG’s energy system is a perfect fit.

Vismara 100 Luxury Sailing Ship

Ice Cat 61 is the largest and most technological catamaran ever built in Italy. It’s a product of craft workmanship, from the design to the materials and the use of cutting-edge technologies. Including its energy system.

Solar airplanes: future or reality?

Are solar airplanes reality?

Flying a commercial passenger airplane from point A to B takes a huge amount of energy and power. If these demands were translated to a sustainable solution based on current technology by replacing kerosene with batteries, the weight would be much higher and more surface would be needed (or more efficient solar cells) to yield sufficient energy.

So it may not be possible for commercial passenger flights yet, but there are several initiatives to prove that solar powered electric airplanes are indeed the future.

One example is the famous SolarImpulse initiative that aims to fly around world on solar energy. The Solar Stratos project takes it even one step further, demonstrating the potential use of renewable energy by taking on the challenge of flying a solar powered electric airplane all the way to the stratosphere (altitude of 20 km).

Apart from these special initiatives, there are a number of commercial manned and unmanned (drone) airplane projects with different goals. Google’s solar powered drone, for example, has the goal to spread internet all over the world, especially to remote areas. These so called atmospheric satellites also fly at an altitude of 20 km.

Solar energy

One thing alle these projects have in common is the need for solar energy to power their flight. This is where MG comes into play. The energy generated from a solar panel is only a small percentage of the available solar power, typically between 20% and 25%. On earth the average irradiation is around 1000 W/m2.

This means if a solar panel has an efficiency of 25% the generate solar power from the panel is 250 W per square meter. Because of the small amount of energy converted by the solar panel, it is important to convert this energy with the highest possible efficiency in order to use it for propulsion or charging batteries.

The Maximum Power Point Tracker (MPPT)

Converting solar power to charge batteries with the highest efficiency is one thing, but solar panels are not an ideal source of energy. Each solar panel has a so called IV-curve, demonstrating the relationship between current and voltage. Figure 1 shows a particular example.

The key to getting the maximum amount of energy from a solar panel is to ‘search’ for the Maximum Power Point, which is called ‘tracking’. A DC/DC convertor with a Tracking function is required to convert the energy from the solar panel to charge the battery or use it for propulsion. This type of converters is called Maximum Power Point Tracker (MPPT).

Figure 1

There are basically two types of MPPT’s: Boost (from a lower solar voltage to a higher battery voltage) and Buck (from a higher solar voltage to a lower battery voltage). The type of converter we developed is a Boost converter. The MG Solar MPPT is a highly efficient MPPT with a ultrafast tracking algorithm.

 

MG’s history of development

The development of our MPPT began when we started building a solar powered boat, to participates in several solar challenges all over the world. After successful usage in this project, it we further optimized the efficiency and Tracking algorithm.

Several other race participants noticed the existence of our converter, for example the TU Delft solar team, participating in the World solar challenge in Australia with their Nuna car

s. They tested their existing best MPPT and compared it to our newly developed one.

Upon concluding MG’s new MPPT had a higher efficiency, they began to use it in their solar cars. After their successful win, more and more teams took an interest.

Now over … teams use our Solar MPPT. Every team has their own configuration and the Solar MPPT’s are tailored to their needs.

It’s possible to customize on voltage range, maximum current, connections and CAN-Bus communication.

The use of MG Solar MPPT in Solar Airplanes
The use of our MG Solar MPPT for racing purposes was also noticed by several solar airplane initiatives. One of the companies, Elektra Solar, implemented it in their one seater solar airplane, to face ‘the challenge of stratospheric manned and unmanned flight with solar-powered and emission-free aircraft”.

MG’s Solar MPPT solution ensures the maximum energy yield from the solar panels while keeping the added weight as low as possible, as you can see on our product page.

Technical specification
Table 1 shows the specifications of the different configuration types now available. Note that customizations to meet your project specifications are possible. Don’t hesitate to contact us if you have any questions or need additional information.

Technical specifications Industrial Solar Boat WSC-Si WSC-GaAs
Input voltage range *1 VIN 22 – 58 V 22 – 120 V 22 – 120 V
Output voltage range *1 VOUT 25 – 58 V 25 – 180 V 25 – 180 V
Output voltage limit VOUT_LIM Configurable *3
Input power range PIN 5 – 450 W *2 2 – 700 W 2 – 700 W
Input current range IIN_MAX 0.5 – 10 A 0.5 – 7 A 0.5 – 7 A 0.5 – 3 A
Input current limit IIN_LIM Configurable *3
Output to input ratio range *1 VOUT/VIN 1.0 – 3.5
Max. input forward current ( VIN > VOUT ) IFW_MAX 6 A
Peak efficiency ηe 98% 99%
Isolated CAN transceiver supply voltage CAN 10 – 58 V
Isolated CAN transceiver current draw ICAN 16 mA at 12 V
Off state current draw -IOUT_OFF 20 µA at 30 VOUT
50 µA at 60 VOUT
Weight    
Weight (approx.)   220 g 540 g 285 g
Environmental    
Operating temperature -20°C to +55°C
Relative humidity Max. 95%  (non-condensing)

Table 1

Solar airplanes in future

Even if we can’t fly a commercial passenger airplane yet, we are eager to see what tomorrow will bring and passionate to develop more technology to make the future a reality. If it’s up to us, rather sooner than later.