“Safety First!”, you may think while watching the following video, but if the cheap (Chinese) polyethylene (?) extension cables just break too often due to rough handling and their low quality, chances are that someone will come up with an alternative. Like this young man in Kenya:
(no subtitles available on this one, sorry)
A young man from Kiandutu slums in Thika had always wanted to be an electrical engineer, but lack of fees denied him a chance to further his studies. And yet this has not dampen his resolve to put his mark on the world of electrical engineering.For starters, he has devised a way of making wooden extension cables, which as NTV’s Jane Ngoiri reports, is causing quite a stir in his neighbourhood. (src)
A max current set by the fuse and wooden frames that may easily burn or conduct electricity while wet probably aren’t the best conditions for this hardware hack, but hey: there’s obviously a demand for such an extension cable.
This gadget was created to solve a real problem with biogas – getting the dung to the system quickly and efficiently. Motorbikes are the taxi’s of Africa so why not? Before I tell you about the above gadget I just want to remind you about the problems we have been having to solve to get the biogas to work at home.
Installing biogas at home has a real experience in afrigadget – we have figured out by trial and error how to get the gas under pressure –
At first we tried using water pressure, but when we stepped back and looked at it we realized that it really wasn’t simple or appropriate for bush applications ..
In fact, all we needed to do was to put pressure on the bags.
The pressure wasn’t enough to run the stove until we modified the stove jets by enlarging them slightly.
Next we had to figure out how to get the dung to my digester – you see I don’t own cows but my neighbors who live a few kilometers away do and are selling it at a very nice rate of Ksh 50 (70 US cents) for two large buckets . The owners are happy to see the dung as it accumulates in the nighttime stockades and attracts annoying flies that carry diseases if left on the land.
The problem I face is common to many folks around here, we rent houses but we don’t have livestock. But there are huge cattle farms around us. So Dominic came up with a solution that creates jobs and moves poop quickly and efficiently.
So we went to the local juakali welder on the roadside to create a dungmobile ..a trailer designed specially for cow dung!
We tested it with a human load to ensure it is balanced … each bucket weighs about 50 kg.
And the first delivery arrived without a problem! 🙂 Big Thanks to Dominic Wanjihia who seems to always have a simple solution to any problem.
I know you are wondering, if it’s that easy, then why doesn’t everyone use biogas?
Now that I’ve got biogas running my kitchen I wonder why so few people have done so in Kenya. There are countless articles, publications, websites and people who will tell you that biogas is the most economical and environmentally sustainable way to produce energy. In fact, the benefits of Biogas have been known for tens of years, and hundreds of systems have been built in Kenya. But it hasn’t really taken off – few of the installed systems are actually working and the uptake of biogas systems at a domestic level has been slower than slow – it’s virtually non-existent. A review of biogas in Kenya reports that technical breakdowns has discouraged uptake but the main limiting factor is cost.
Here’s a simple comparison of costs – from continuing using charcoal/fuelwood or Kerosene and LPG to using various biogas options.
Cost (US$ )
Time to install (days)
1,500 – 2000
2,000 – 3,500
Flexi bag envelope
10 – 15 years
Fuelwood or LPG cylinders
200 (per year)
For a simpleton like me these figures are immediately revealing – it takes 2 years to pay off a flexibag digester after which domestic fuel is free for at least the next 10 – 13 years. For the underground systems you have got to be hugely rich, or suffering from environmental guilt to make the decision to switch to biogas – from an economic perspective it will take 10 to 20 years to pay back. You could grow your own trees and make your own charcoal in that time frame….
Why is it so expensive for the constructed biogas systems? Because most of the biogas systems in use are constructed systems requiring engineering and masonry, they are very expensive, take weeks to install, require experts, and intensive follow up. If they go wrong it’s a major engineering task to fix it. This is why we are promoting the flexible bag option for domestic and small industry use.
Congratulations to Skylink Award winning Kenyan biogas innovators
I thought skylink was an airline… Biogas operated planes???
Their industrial scale system costs Ksh 1.6 million (US$ 19,753). Such installations may need to be financed by the Government institutions where they clearly make enormous economic and environmental sense for schools, prisons and other large institutions.
For small scale house hold units, we need solutions that will compete against the cost of installing LPG or using charcoal, firewood or kerosene stoves. When we talked to local Maasai near Nairobi they found the flexi bag systems appealing because they could be purchased with the sale of just 2 or 3 cows, can be rolled up and moved when they migrate, and it saves the women the work of searching for firewood, it’s hygenic because water can be heated for bathing children, while it also removes dangerous piles of rotting cow dung near the homesteads which are breeding sites for biting and disease carrying flies which affect livestock and people.
You’d think that given the amount of cow dung available around rural Africa that biogas would be a big hit right? Well, its actually relatively unknown. The main reason is materials, coast and complicated technology. People in these areas use charcoal or wood for their domestic cooking needs – its not only dirty hard work to collect firewood, but it’s unhealthy and damages the environment. But, it’s free …
We believe that biogas from cow dung holds huge promise for rural and urban areas as a cheap source of energy that can be turned into domestic use or even business anywhere in rural Kenya….eg. pasturizing milk, making yoghurt, running fridges, generators, hammer mills for grinding corn, cooking, baking, heating water, running machines… and reducing your carbon footprint.
I have recently become the latest guinea pig for Dominic Wanjihias experiments … and it has been quite a learning experience
Problem No. 1.The system needs to be cheap and mobile for communities who don’t own land or who move regularly (pastoralists)
After only 2 weeks it will have ballooned like this
Problem No. 2. The pressure is not enough to light a stove. Nothing ever works as you initially planned that’s why having a fundi like Dominic around to modify, adapt and rethink as you go along helps so much.
To create pressure Dominic got two tanks, and did some juakali pipe connections. One tank was placed above the other. The lower tank was filled with water. Long pipes and short pipes were put through the lids and specially made holes in the tanks … It’s all about applying simple physics really…
Then using a pump ..(we’ll be using a modified bicycle pump next time) he was able to move the gas from the flexi bag to the lower tank and displace water to the upper tank. This water creates enough back pressure to get the stove to light.. that’s the theory … here is what happened.
A curious boda boda rider (motorbike taxi) called Victor volunteered to help… Rhoda watched in awe
“Houston we have a problem” …Ok, accidents are bound to happen…pressure pushed the pipe off and Victor got soaked..just water though. The top tank fills with water as you pump biogas into the bottom tank, and the water drains back to the bottom tank as the gas is used
Course all this hard work was not for nothing – we had to make a cup of tea –
It took 15 minutes for the water to boil!
Yes we are very very proud that the system worked so Cheers! a well deserved cup of tea.
We estimate that it took about 1/4 to 1/2 of the gas in one blue tank to boil the kettle – that’s about 1/8th of a cubic meter – and the entire flexi bag contains about 5 cubic meters… which means we have about 10 hours of gas use…..and the stuff is being produced all the time (we had quite some wastage as we fooled around to get the system to work)
Well it all seemed to be going just fine when …pssssssttttt
Nothing serious but we were losing a bit of gas through one of the lids (holes had been drilled through the lids to insert pipes) …we need to fix that before we build up any pressure in that tank.
If you are interested in biogas let us know! Leave a comment.
I got this photograph from someone who had his teeth repaired in Gikomba – the center of Kenya’s Juakali innovation, and another one of Kenya’s slums . The home made gadget looks pretty terrifying but check out the results!
Made from brass and modelled on something much more professional, this manual tooth mould (I’m sure there’s a technical name for this gadget) is cheap and brings smiles back to faces.
Amid the squalor in one of Kenya’s most depressing slums, there is a surprising amount of flashy colour and fun
Njuguna makes these toys because he like to! His clients are local people in the slum but he does sell well outside of that market too.
I was especially enthralled by this scrap metal motorbike but the price was Ksh 2,500 (US$ 30) which may have been a special price for visitors like me – I couldn’t afford it!
Scrap metal gocart – boys in heaven!
Njuguna also makes beautiful micro toys for a specialist corporate market – they had been sold but he had photos
You guessed it – client was Safaricom!
Amongst all the toys were some other serious gadgets that Njuguna had put together for no specific reason -a couple of free standing windmills rotate rapidly in the narrow streets that channel the wind. They stand there like artistic monuments, but Njuguna told me that he made these constructions made from parts taken from broken cars and had put them out and was waiting for an idea to strike him regarding what to apply them to. He called it his research experiment. … somewhere else lay another of his inventions, a waterpump …..(should I have suggested something?)
Kids play by open sewer in Mathare Valley
Visiting Kibera was disturbing in so many ways
….and yet it was thoroughly invigorating and inspiring – a pleasant surprise . If you ever get a chance, do visit and seek out the Njuguna’s tucked away in narrow streets. These brilliant artists and innovators might live in what seems like the worst hell on earth, yet somehow it feels like they choose to.
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