Re-Engineer is Back!

It has been since 2007 that I last posted a blog about renewable energy in a developing context. At that time the focus was mainly about the potential of biofuels in the Pacific. After having developed into the "coconut oil biofuel man" of Fiji, I have been continuing working on similar subjects, but in different capacities. First in The Netherlands during 2008-2011 on financing of promotion of Renewable Energy programmes around the developing world. After that, I moved to a position in Mozambique where I have been working on implementation in solar, wind and hydro power.

After a few years in the field, I think it is time to start blogging again, with the same investigative spirit as before, providing not only answers but also posing questions while at work on how to improve the access to energy for the more marginal areas of the world.

Solar PV module for mobile phone battery charging in Manica Province, Mozambique

Questions that I would like to deal with here are: What are effective strategies for rural electrifcation in Africa? How is renewable energy in the developing world linked to climate change? Which technologies are appropriate for rural electrification? What are typical pitfalls of energy access programmes? This blog will aim at addressing these questions with regular intervals.

COCONUTS HILUX - Efficiency of running on coconut oil blends

In my private life, I have been experimenting with the use of coconut oil in our vehicle. It is a Toyota Hilux 2.4l and it has become some sort of a hobby to fiddle around with the car an trying different blends. I have recently posted an update on the coconuthilux pages which is a set of web-pages that display the trouble and the fun I went through with using coconut oil as a fuel.

My findings on the efficiency go:

The most frequently asked question by people when they see my 'cocopowered' sign at the back of the Hilux is what them mileage is on coconut oil. In the beginning, I could not see any change so I would respond that it is actually the same.

During the course of time, man grows wiser. Theoretically, the calorific value of coconut oil is lower than diesel. The average energy content for a litre of diesel is 42 MJ/litre and coconut oil typically shows an energy content of 38 MJ/litre. On the sole basis of these numbers, you would expect 8-9% less energy in a litre of diesel. Of course the energy content of diesel varies (with its distillation curve) and so does the energy value of coconut oil.

In addition, if the moisture content of the coconut oil you use is 2% (an analysis shows most Pacific island copra oil has 1-2% moisture), during combustion, 2% of the volume of the fuel must be evaporated out of the cylinder, absorbing energy. This obviously decreases the total efficiency, as diesel is normally 'dry'.

So it would be expected on the basis of these basic physics facts that the mileage on coconut oil is at least 10% less than diesel.

Coconut Oil proponents (Coconutters) would argue that diesel burns with a 'bang' whereas coconut oil burns more slowly, creating a more subtle force in the cylinder, increasing the overall efficiency. Laboratory tests in PNG indicate that the energy content is a good predictor of the fuel efficiency (in Litre per kWh or litre per km) so that theory is the only one standing.

Now my own experiences. It is very difficult to scientifically assess the efficiency of a vehicle if you don't equip it with a multitude of electronics and data loggers. The operational characteristics of an engine change significantly if you drive through town stopping at traffic lights and going up-hill versus off road driving or hundreds of kms driving over flat tar-sealed roads. For the coconut hilux, in the past years, all of the above apply. And all I logged is kms and litres. In addition, I've had to clean out my tank, losing fuel. We've had criminals stealing fuel from the bottom of our tank while we were relaxing at a resort. We've had a multitude of filter changes.

Nevertheless, the graph below shows the efficiency of various periods of driving (typically 1,000 - 1,500 kms) with the average percentage of coconut oil in the fuel for that period. The total period is from January 2004 through to November 2006, that is almost a three-year period.

Findings for the last three years:

The trendline, calculated with Excel shows a negative correlation with coconut oil percentage (as expected) but much higher than theory suggest! A 30% blend of coconut oil gives almost 6% less mileage in litres per km. If it is a complete linear correlation (which I do not expect), it would mean that 100% coconut oil leads to 24% less efficiency in km/litre.

The other observation one can make is that the hilux consumes a sh^&*$%*t-load of fuel to get anywhere, really.

COCONUTS HILUX - Update December 2007

For about two years I had information on my experiences (for info and for fun) posted on a website (see links to the right). However, the provider (cheapcheap) is not so reliable and often it was not accessible. So I've posted the most important information on this blog for people who are interested to copy what I've done (are you sure?) or just people that wonder why I'm getting myself into so much trouble everytime.

Well, everybody needs a hobby and mine is to get myself greasy with coconut oil just to gain some more insight in what are the limitations if you want to avoid making biodiesel (esters). So, the journey continues with some of my latest supply of oil.

COCONUTS HILUX - Technical Problems



During one of our many trips through Fiji, I am replacing a fuel filter. This is no fun job as afterwards, everything smells of diesel fuel. During replacement, you need to fill the new filter with fuel, otherwise you cannot de-air the system properly.

A number of times I had blockage of the strainer inside the fuel tank and the only thing to do is empty the whole tank, remove it and clean it. Once you start filling bottles, you realise how much fuel actually goes into a tank (65 litres). If you don't have garage equipment to do this job, there is a lot of work involved in getting the tank empty.



The fuel tank is now empty and can be cleaned. The fuel is all over the place and it turned out that the inside strainer was blocked. This repair cost me 4 hours to complete.


This is the strainer that I found in the tank. It is clogged with fatty greasy particles. They are part of the crushed shell of copra during the process and caused by lack of filtering.
Once cleaned, I also punctured some holes in the strainer so as to minimise the chances that I will ever have to remove the tank again. After this, I always filtered oil before pouring into the tank.


This is my first fuel heater that I made from copper tubing, wound around the rubber hose of the cooling system. It never really worked well, because I could not de-air it properly.

The second problem was that it became really hot once I shut the engine down, as the fuel stops streaming through, but the engine is still very hot. I am not sure how hot, but I reckon it could get close to the spontaneous burning temperature of diesel.
It is also not very effiicient and can damage the rubber hose over time, So I removed it again.


My second fuel heater is a design from Tony Deamer in Vanuatu. It contains of a spiral of copper tube inside a larger pipe. The cooling liquid flows through the pipe and the fuel through the copper spiral. It works very well and the emissions are visually less than without.
After using it one day, a hose blew, causing a leak and subsequent overheating of the engine.
After three days the injector pump started leaking significantly. After removing the heater and lowering the coconut oil blend, it has ceased leaking.

When using this heater with a mixture of 40% diesel, 10% kerosene, 50% coconut oil, the injectorpump started leaking like hell. It was at the point where you could follow the car around the city, with the black spots of coconut oil on the road. Especially immediately after a cold start, it would easily create a pool of fuel under the engine. No good.
I visited some injector specialists here in Suva and they told me they can only replace the upper seal and have a standard set of replacement rubbers for the pump. It was going to cost over $600 just to get it out and work on it. Then I decided to finish the blend in the tank and get real; Why am I wrecking a good car with the juice of the nuts on the waving coconut trees?

Still, the question haunted me, why did it leak? Was it because of the increased temperature of the fuel? Was it because of the composition of the fuel? You would expect the fuel to leak through the seals if it gets too hot, but why would it leak the fiercest when the engine was still cold?

A lipid specialist from the local university offered a theory based on the chemical-electrical properties of coconut oil, causing some types of rubber seals to 'open' when diesel would keep them closed. Well, it could be, but it's is difficult to ensure whether this theory is correct. What would be too bad is when this means I cannot utilise coconut oil and it also implies that many other cars would get problems with coconut oil in their diesel blend.

In the period Jul/Aug/Sep I have not been able to run on coconut oil because it solidified in the drums in our yard and because I was away on duty travel. My wife does not mind the trouble I go throug in getting the fuel blends prepared, but she'd rather just fill up at Shell, and I don't blame her for that.

Now it's heating up again (spring is in the air!) and I managed to get my coconut pumped out of the drums again.

This time I tried it without kerosene (see page "what fuel has the coconut hilux used") and to my big surprise, at a blend of 60% coconut oil and 40% diesel the injector pump does not leak.

New theory: perhaps the heated kerosene caused the leaks?

Update on tech problems 2006:

The Hilux continues to run fine. It started more and more difficult with oodles of black clouds and thus I replaced the glow plugs. Of course, the electrical connections and the plastic nuts on top gave way so this turned out into a one-day operation. Nevertheless, with the 'original Japanese' replacements, the Hilux still starts great.

If the coconut oil content is above 10%, we need to glow until the hilux starts beeping to avoid excessive long starting or black smoke. Do not forget in the morning in Fiji these days it is still 25 Deg C.

Fuel filters have been replaced so many times, I lost count. But they actually never blocked on me during the last year. I just try to avoid any issue with my wife getting stuck somewhere. So every 10,000 kms there will be a flashing new filter under the hood. I used the old filter to pre-filter the coconut oil before it goes into the tank.

COCONUTS HILUX - Car Adaptations?

Initally, I have built in a fuel heater which uses the coolant of the engine to heat the fuel before it is injected. However, the adaptations that I incorporated created problems with my heating system. This is probably nothing to do with biofuel, but with my skills to build in a heating system. However, I have eventually decided to leave all adaptations out.


The fuel heater

Update on 18 October 2005:

I have removed the heater as it created problems in my cooling system (leaking and hoses broken). Even though the emissions looked better when I was using the heater (at higher blends of coconut oil), the engine runs fine at 40% diesel and 60% coconut oil.

The injector pump does not leak anymore and the only reason why that might be is that I am not using kerosene anymore. Will be continued ....

Update on 18 October 2005:

I have removed the heater as it created problems in my cooling system (leaking and hoses broken). Even though the emissions looked better when I was using the heater (at higher blends of coconut oil), the engine runs fine at 40% diesel and 60% coconut oil.
The injector pump does not leak anymore and the only reason why that might be is that I am not using kerosene anymore. Will be continued ....

Update December 2006

NO ADAPTATIONS anymore. I've given up on heaters and filters. It's just the hilux, me and the coconut oil (and perhaps a bit of diesel).

When I buy the coconut oil I let deposits settle for a couple of weeks. Then I pump it across to smaller jerry cans and pump it through a regular fuel filter before I throw it in my tank.

COCONUTS HILUX - How much fuel from which source has been used by the Coconuts Hilux?

The amount of coconut oil in the fuel blend of the coconut hilux has seen some interesting high and lows.



During the first peak to 10%, the fuel filter was replaced because water remains reacted with the coconut oil in the tank and subsequently plugged the filter. After two replacements of the fuel filter, this problem did not occur anymore. In the first period, cooking oil at US$1,5 per litre was used.

After the first drum of coconut oil was acquired, a more economic source of coconut oil was found at 0.6 US$/ litre.

This coconut oil had a great amount of particles and when this was put in the car in larger amounts (first peak over 60 percent), the internal strainer in the tank got blocked. Only after cleaning the tank twice, this was found and after cleaning this an adding extra holes, the engine operated back to normal.

Ever since then, I have been using a fuel filter before getting any fuel in the tank.
De-airing the fuel system was a major cause of problems after any alteration to the system.
Only recently virgin coconut oil that was slightly rancid was donated to me by a Pure Fiji, a local cosmetics manufacturer. While using this oil, I also included the fuel heater. This fuel heater worked very well and the exhaust had visually improved.

After a couple of days the injector pump started to leak significantly. Now the heater has been disconnected, the system stopped leaking, so it seems the hot fuel came through the gaskets of the fuel pump.
To be continued...

The amount of coconut oil does not seem to alter the mileage too much- it tends to be slightly lower with higher blends. Theory suggests that an engine requires 8% more coconut oil in volume than diesel - through its lower energy content and slightly higher density.

The graph to the left is a result of all the numbers the fuel I entered into the tank, placed in an XL sheet. It was a bit of figuring out how to calculate the blend. Think about it: you have 50 litres diesel, 5 litres coconut oil, 1 litre kerosene, you drive 200 km, add 30 litres of coconut oil. What blend are you left with? Anyway, I figured out a way with XL using the average mileage of the Hilux which approximates the blend in the tank pretty good. On the times that I had to empty the tank, I also had some nice reference points to check my calculations.

Now about the content of the graph. In the first period, I tested the 'waters' or better, the oil, as a slight addition to the diesel. No problems during that stage.

In the second stage, I obtained a big drum of coconut oil and started to increase the blend, utilising 15% vv of kerosene for each 85%vv of coconut oil whichever amount I added to the diesel. I had some starting problems (white smoke or very black smoke when it eventually started) and the problems described on "adaptations" with the strainer in the tank.
Around a 100,000 km I have been running on pure diesel, because the coconut oil I had in my yard was solidified and I could not get it out of the tank. Now the weather in Fiji has heated up again and I am up and running again!

Update December 2005

After the "winter" has passed and warmer times have come around, I have re-engaged my coconut oil pump and started to blend fuel again. I virtually stopped blending kerosene (note the area after 103.000 is mainly green / grey, no yellow base anymore.

Here is the reason: with kerosene, the injection pump will leak, without, it won't. The blend that is widely used in Vanuatu (15% kero, 85% coconut oil) somehow does not suit my car. According to biofuels expert, Dr. Gilles Vaitilingom, the blend with kerosene does not make more sense than trying to bring down the viscosity of the mix. He indicated that when the (kerosene) blend is injected in the cylinder, the kerosene will burn first, then nothing, then diesel will ignite. Therefore, the combustion process is totally different for what the engine is designed for.

Then, at 105.000, I got serious heating problems. I suspected the coconut oil had something to do with it, as I thought to observe an increased level in the oil sump. Reality was that my local lube-oil mechanic had put in too much... The heating problem was directly connected (it turned out later) with a problem in my cooling system. When I had fixed it, I again started to blend coconut oil in the diesel. The yellow area in the 107.000 area is my own stupidity: with a sleepy head I accidentally poured in 5.5 litres of petrol. It caused no problems and it will slowly disappear from the tank!

Update December 2006:

The last bit of yellow in the graph is a special Phillipino additive that I was given by the Fiji Department of Energy. It is produced by Tuks Oil and would assist in burning coconut oil. The content have been mysteriously unclear but I can tell you that my Hilux just smoked more. I cannot see any improvement, hence I stick with coconut / diesel blend.

My dear friends gave me a drum of coconut oil from the coconut oil mill in Savusavu for my birthday and I'm blending that with diesel now. Smells great!




Renewable Energy for Development

Update on SOPAC Biofuel work online

There is a new update on my work websites describing work carried out lately with regard to a biofuel project evaluation (Copra, see links on the side of the frame) and progress with regard to a coconut oil fuel plant in Samoa (CocoGen).

The biofuel project evaluation in Fiji shows that in many instances Pacific communities have excess coconuts and excess labour and automatically it is assumed that the excess labour will be available to turn the excess coconuts into oil, provided the right equipment is made available to them. However, as it often turns out, individuals, especially men, have the tendency to optimise on their leisure time, instead on their maximum utility of the environment. In Fiji, both specially adapted generators do not run on coconut oil anymore. One is broken beyond repair and will have to be replaced and the other one runs on diesel. The community found it easier to just buy fuel from proceedings of farming and land leases, instead of going through the trouble of producing fuel themselves.

The CocoGen inception report finds that a coconut oil fuel factory in Savai'i, Samoa is possible but that there are severe economic risks associated with the investment. As the oil price keeps its volatile character, the viability of the coconut oil fuel factory might come under fire. In addition, as the last copra oil producing entity (COPS) went into bankruptcy last year, the problems in the copra sector, especially the low returns at farmers level are showing the significant challenges of even producing small amounts of fuel from coconuts.

Niches still appear to be present in the Pacific biofuel sector, in areas with extremely high fuel prices and low alternative wage options for farmers.

The Pacific Island Business has recently published an article written by my colleague Shane Fairly and myself with an overview of the developments in the biofuel sector for the Pacific.

You can view the article by clicking on this link.

Biofuel study for Remote Electrification

The use of biofuels is increasing in popularity through the rising world market prices for fossil fuel. Especially on outer islands, the use of coconut oil can be a viable alternative through the high transport cost to get copra off the island and to get fuel to the island. This notion has lead to SOPAC activity in the region, in partnerships with UNDP and with the French Transénergie.

Man with coconut kart, Kiribati

Remote Electrification Business Model for Marshalls

The Marshall Islands were visited during October 2006 by a team which consisted of business development expert Mr. Evers from UNDP Suva and Mr. Cloin, energy adviser from SOPAC. The mission was funded by UNDP with in-kind contribution from SOPAC. Subject of investigation was the feasibility of setting up a small coconut oil mill for fuel on the island of Ebon, which is 200 miles south of the capital Majuro.

The mission was organised locally through the Marshall Islands Energy Office by Ms. Myazoe and was joined by Hon. Silk, minister for Resources and Development Mr. Hacker, Economic Planning Unit and Mr. Schutz as a representative from the Marshalls Energy Company (MEC).

A small number families and shops in the outer islands of the Marshalls are electrified nowadays with small petrol/diesel generators and a larger number of individual households with PV Solar Home Systems. Even though most users of PV systems are quite happy with the light and power for radio /TV provided, they would rather have access to more power. In this light, it was thought, communities can have access to more power, using a gen-set, for which they make their own local fuel.

The mission held a series of community meetings, to gauge the interest of the local community to engage in coconut oil milling using a small copra press. It appeared that the local community is very interested in the local value adding of copra on the islands. The cost of the oil would be around a factor of two lower than the current price of diesel on the outer islands.

The greatest challenge was found to be the small volumes of oil that are needed on the island to make it viable to write off the mill and pay for its maintenance. In addition, even if the price of coconut oil is much lower than diesel, the effective cost of around US$3 per gallon, or US$ 0.80 per litre makes for cost of energy around US$ 0.4 -0.5 per kWh.

At this price, it is only the very high income households would be able to afford this energy. It will be further investigated how a community based Rural Energy Service Company (RESCO) can find a sustainable economic solution to this challenge.

The draft pre-feasibility study of a RESCO operation on Ebon will be circulated for comments before the end of 2006 and might form the basis for a pilot project, making the energy supply on the outer islands of the Marshalls cleaner and more independent.

Hybrid Solar PV – Biofuel System in Kiribati

Kiribati was also visited during October on a related study, funded by the French Pacific Fund and implemented by Transénergie. Mr. Sauvage, hybrid system expert and SOPAC energy adviser Mr. Cloin visited the outer island of Abemama to investigate the viability of building a hybrid system using both solar and biomass energy. The project will study a site in Kiribati (this mission) and a site in Fiji, in collaboration with the Fiji Department of Energy, early 2007.

Most outer islands in Kiribati are, just like in the Marshall Islands, electrified by a combination of petrol/diesel generators and Solar PV. On the island of Abemama, 150 households, or 25%, use a solar PV system that is owned and maintained by the Solar Electric Company (SEC) based in Tarawa. The experiences with these systems are very positive, for powering lights and radio. The telephone company, KCMC uses a large array of solar PV panels to provide a telephone and internet connection to the island.

For larger systems, such as some of the boarding schools and offices, mostly small diesel generators are used. They run only 4 – 6 hours per day and more often than not, are only partly loaded. This makes for very inefficient power generation and thus high cost to the user.

The study focused on how this efficiency could be improved by creating a hybrid power system that combines the forces of both solar PV and the diesel generator. As an additional “renewable energy” component, the study also looked into replacement of diesel with coconut oil so that the combination would become 100% renewable. Another very important part of a hybrid system is storage, which could be a flywheel or a battery. This enables storage of electricity when there is over-production and allows electricity to be provided during times that both the sun and the gen-set do not generate electricity.

After visiting most parts of the island, the power system at the Chevalier boarding school was chosen as the subject of study. It was investigated whether current and future electricity generation could be provided by partly solar PV and partly a gen-set running on coconut oil. Most technical problems of engines running on coconut oil are caused in part by the fact that engines do not run at full load. Because a hybrid system contains a storage component, the engine can be run at close to full load when it is operated, increasing its efficiency and decreasing the rate of deposits on engine components. The average of 5 sun-hours in the outer islands of Kiribati will make for the balance of electricity by a solar array.

The preliminary findings of the study show that this setup can be favourable as compared to the current stand-alone diesel generator, provided the initial investment is covered by a donor. Nevertheless, one of the challenges found is the relatively high beach price (AU$ 0.6 per kg) of copra on the outer islands of Kiribati. Given that, it would cost about US$ 1 to produce a litre of coconut oil on the outer island. Because the fossil fuel prices are also subsidised (US$ 0.89 per litre) on the outer islands, the cost ends up to be lower for diesel than locally produced coconut oil.

There might be a chance that copra subsidies are ‘waived’ for the purpose of producing biofuels as it decreases the transport cost of copra from the outer islands to Tarawa, taking the net value of coconut oil in Tarawa as a point of reference. In addition, the study will take various price levels of fuels into account and investigate which could provide a sustainable model for Abemama.

Rural Electrification in Outer Islands using Biofuels in the Pacific

The opportunities to utilise locally produced coconut oil on the outer islands for remote electrification are present, but careful investigation of local economic and supply constraints need to be taken into account. Without waiting for the time that the oil price has gone higher than US$ 100 per barrel to make it viable, even with the small volumes required and the subsidised prices, pilot projects to gain experience with remote electrification with locally produced fuels are justified to make the island communities more independent in the long run.

There are many things happening with biofuel in the Pacific, now that the oil price has gone up significantly. As customers on the receiving end of the supply chain of fuel products, it is the Pacific islands with their relatively small volumes of fossil fuel products that feel the price increases the most.

Even though the price levels in the Pacific are not as high as most European fuel prices, caused by lower taxation in the Pacific, the people feel fuel price increases through everything as the cost of producing power goes up, just as driving, boating, flying, imported goods.