Archive for the ‘Energy’ Category

Gigantic Electronics extension cable

“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.

Poop piki piki for my biogas system

Piki piki means motorbike in Kiswahili

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.

Options Cost (US$ ) Time to install (days) Labour Maintenance Durability
Fixed dome 1,500 – 2000 21 5 people Low Decades
Floating top 2,000 – 3,500 21 5 people Low Decades
Flexi bag envelope 400 1 1 person Low 10 – 15 years
Fuelwood  or LPG cylinders 200 (per year) 0 0 low Decades

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

We would ;like to congratulate Skylink Innovations who have just won a the Ashden 2010 Award for their biogas installations in Kenya.

Skylink recieve the Ashden Award from Sir Richard Attenborough

I thought skylink was an airline… Biogas operated planes???

Human waste digester under construction in Meru Prison

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.

Solving the flexible biogas digester problems

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)

Simply Logic flexi -bag for biogas - small, cheap and made of parts you can find in any hardware

Biogas system on a motorbike in Kenya

You may need a Dominic to help set it up

It can be dirty work - but don't let that discourage you...

After only 2 weeks it will have ballooned like this

After only 2 weeks the bag will have inflated with methane - beautiful biogas

Great party trick: The biogas will burn and amaze

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…

You need a few tools - all available at tusky's or Nakumatt

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

Victor pumped... others set up the stove

“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

Houston, we have another problem...we sprung a leak!

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.

Nokia: Bicycle Charger Kit for Mobiles

There was a major announcement today from Nokia about the release of cheap phones for the emerging markets, featuring dual sims and the ever useful LED flashlight. What is even more interesting is that with the launch of the phones, a bicycle charger kit. According to CNET Asia, the kit will be available by year’s end.

Bicycle charger kit for mobiles

Rounding up the announcements today is the Bicycle Charger Kit, which comprises a charger, dynamo and phone holder. When docked to the latter with a 2mm charger jack, the electrical generator will produce energy to juice up the handset. According to Nokia, the dynamo starts charging when the speed of the bicycle reaches 6kmh and stops when it hits 50kmh. It matches the efficiency of a normal charger when the bike is traveling at 12kmh.

The bicycle charger kit will be useful to many people in Kenya and other emerging markets, its only a matter of time before it is repurposed to charge other devices like small radios. All in all the phones seem AfriGadgetty, what with their dual sims; perfect for markets where people have more than one carrier – thinking of Nigeria here, where its not uncommon to see someone with multiple phones because of varying network coverage/dependability + LED flashlights, it is clear that Nokia is making products that have utility for millions of people around Africa. Personally I can’t wait to try out the phones and mobile kits as soon as I can get my hands on them. Come to think of it, this is hardware localization, something that could go hand in hand with the software localization we are clamoring for in the African market.

Bicycle charger kit for mobiles

For modded bicycle posts from the AfriGadget archive, click here.

Many thanks to my friend Cyrus for the heads up, I think he has just inspired me to blog again.

Building a (one-stage) Anaerobic Digester

David of the Kenyan Community Initiative Support (KCIS) recently built a very low tech Anaerobic digester using only a drum, a valve and some pipes:

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The balloon shows that gas is being produced. The costs for the drum and professional valves may already be too high for some, and the design isn’t that optimal. They intend to add a storage drum with a water-filled header tank for constant pressure and the loading & desludging processes obviously still require some work.

We still like the approach though, because it does indeed “prove the theory”, as David notes. The theory of building a rather small anaerobic digester that will even work with smaller amounts of organic waste.

Goes to show that producing methane gas from something which would otherwise remain unused (livestock faeces usually kept in such drums for a few weeks without harvesting the methane potential) still is an interesting alternative & well appreciated once costs are covered.

Jua kali dressed in Mitumba

Cat walk ready arc welder

Catwalk ready arc welder

This bizarre fabricated arc welding machine is the unique collaboration between jua kali and mitumba. Jua kali literally means hot sun in Kiswahili, and refers to the informal small traders who work outdoors in the sun fabricating mostly work metal and wood items, fixing cars and other household items. Unable to afford new tools they fabricate their own out of locally available materials. Mitumba refers to the second hand western clothing sold on the streets of many African cities. The arc welder uses stolen scrap and second hand wires that are coated for insulation using strips of cloth torn from unsellable mitumba clothes.  This is then wound into the welding machine coils.

God help James if it rains

God help James if it rains!

I’d gone to Limuru to get a welder for a job on a dairy where I met James Mutahi. He is a typical jua kali wrought iron artisan who operates on the sidewalk outside his street workshop using his own home made tools.  I’ve seen jua kali home made arc welding machines before but usually they are housed in a protective box. To save money James dispensed with the casing revealing the guts of his arc welder.

James was making security grill for a window. There’s a huge demand for arc welding in Limuru especially for gates and window bars which are essential in the high risk security zones of Nairobi and other urban centers.  Nairobi’s security is the result of the collaboration between mitumba and jua kali!

The picture speaks volumes about the Jua-Kali sector in Kenya– cost saving is paramount whilst safety is overlooked hence no housing box – look for welding goggles, fire extinguisher and other safety gear.

(This submission is from Dominic Wanjihia)

Fuel saving Sufuria

Here’s another interesting idea from Dominic Wanjihia (see links to his other gadgets below) – the fuel efficient Sufuria. A sufuria is the aluminium pan that is used by virtually everyone in Kenya to make tea, ugali and for cooking vegetables. Like all pots that we use, energy is wasted around the sides of the pot. In Africa this is expensive as fuel be it gas, kerosene or charcoal  is expensive. sufuria 1

This is what it looks like when assembled

Sufuria Kenya afrigadget

Sufuria Kenya afrigadget

This is what it is comprised of – two sufurias to make one efficient one. Basically a hole is cut out of the bigger sufuria – and the piece cut out becomes the lid so nothing is wasted. To wash the sufuria you just dismantle the pieces by just slipping it out. The heat that otherwise escapes around the edge of the pan, is trapped between the cooking pot and  it’s sleeve.

Though it’s not in production, Dominic is using this sufuria at home and swears that it saves at least 50-75% energy on a kerosene stove (his estimate is based on how long it’ takes to boil water).

So if you put a fuel efficient sufuria on a Kinyanjui fuel efficient stove I wonder how much energy saving you could achieve?

Dominic Wanjihia has been previously on Afrigadget showcasing his flat parabolic mirror, container garden, wearable Solar Panel vest, Food dryer, and camel milk cooler.

Flat parabolic mirror is not an oxymoron!

Can a parabolic mirror be flat? Dominic Wanjihias latest invention may prove that this is the most efficient way of capturing solar energy.
flat parabolic mirror 2

Everyone knows what a parabolic reflector is, right? It’s supposed to be a curved surface that collects energy by converging it towards a focus. Parabolic reflectors were invented a very long time ago and have been used in satellite dishes, spot lights and car headlights to name a few. They are also widely used for alternative energy projects to concentrate solar energy for heating and cooking.

Dominic (designer of the flexible solar vest, the solar dryer, and camel milk cooler for Somalia) thinks that the parabolic mirror should lose it’s shape which is an obstacle, to transportation and function.

So how does the flat parabolic mirror work? Dominic has cut inch wide 2 foot long pieces of flexible acrylic mirrors and arranged them at specifically computed angles. When angled towards the sun, this creates a perfectly focused beam of light.

flat parabolic mirror

This concentrated energy can be used to heat water in a pipe for numerous purposes including generating electricity. The beauty of this gadget is that

  1. It is very cheap,
  2. It can be quickly dismantled or moved,
  3. It is easily transportable as it can be carried flat or in a tube,
  4. It is easily repaired if broken as the individual mirror pieces can be replaced (rather than having to fix or replace an entire parabolic mirror).

Please note that this is part of Dominic Wanjihia’s ongoing project with Nairobi University and MIT’s FabLab where he is doing a course.

Fab lab sign .

Recycling car batteries in Rural Kenya

Maina, Rhoda and little Winnie are  a typical Kenyan family who live on the outskirts of Nairobi in an area that has no electricity.

But they have solved the problem of getting the daily news

rhoda family2

When I visited their home I was impressed that despite the lack of electricity, Maina has come up with an innovative solution and is able to keep up with whats going on and listen to his favourite Kikuyu music all day long!

taking it down

Here’s a better look at the system – a second hand car battery hooked up directly to his radio

Radio charger

The wiring is simple

maina showing

Fully charged the battery last 2 weeks. To recharge Maina has to take it to a place in town for 24 hours at a cost of Ksh 50 (about 80 cents US. If he were to  use ordinary batteries Maina would be paying several hundreds of shillings per month (15$) and creating toxic waste with their disposal (Kenya has no battery disposal system).  No wonder used batteries are in such huge demand!

bicycle ride2

And no wonder this family is smiling!

I’m wondering how much it would cost to hook up Mainas battery to a solar panel and  some lights. They currently depend on hurricane lamps.  Powered with kerosene these are not only a weak source of light but are dangerous and prone to cause fires.

rhoda lamp

Got any ideas anyone – can we charge a car battery from solar?

Post note:  This story was found while making a video slideshow about this average Kenyan families carbon footprint for WildlifeDirect.

Solution for Nairobi Blackouts

It’s no secret that Kenya’s rivers are running dry as a result of forest destruction and environmental degradation which has led to a season of blackouts in the capital city Nairobi.

Typical of the ingenious people of Nairobi one street vendor has cashed in on the crisis with this wonderful gadget which he markets as

“Perfect for Nairobi black out”

juakali lamp1

As you can see I could actually read by the light of this lamp which is made from a used tin can, some pieces of wire to make the connections

juakali lamp3

And the battery compartment is ingeniously crafted from a circle cut from a retired flip flop.

juakali lamp2

I love my juakali lamp and everyone that I know  in Nairobi needs one of these lamps. Everything about it is so true to the juakali spirit – hand crafted using colourful recycled tins, and designed for a real purpose with a handle so you can move it around from room to room or hang it up. The vendor tried to sell it to me for Ksh 350 but we settled on Ksh 200 (about $2.50) though I’m sure he would have gone cheaper but the traffic was moving and I had to go.

If you want one visit the Nyayo stadium roundabout.  They stood out amongst the chinese junk that vendors are selling you could practically kit out your house from the junk on sale there. Here’s a short list of what I saw during my 30 minute traffic hold up:

Pens, hats, footballs, blow up spiderman (who needs one of these?), peanuts wrapped in newspaper cones,

smelly car things, driveres licence holding cases, scarves, giant maps, Kenya flags, apples, kits (spiderman kites),

Nike shorts, cowboy hats, socks, oanges, backpacks, cheap watches, key chains knives, olympic medals (yes I wanted one of those!),

knee length shorts for guys who sag, hazard ttriangles, cables to cack your car, name tags for meetings, torches, window wipers (!),

car mats, pears, plumbs, tiny folding chairs for children (or Chinese people?), vehicle number plates, fire extinguishers, stickers,

Enormous framed pictures of furry cats and snow leopards (I can just see one of these this in my house), bananas and bandanas, plastic lunch boxes, pillows and cussions, a huge variety of stuffed toys,

posters with Jesus’ sayings, polo shirts, stearing wheel covers, spanners, screw drivers and of course my favourite – juakali lamps.

Nairobi never fails to impress. I love it. What else have you seen on sale in the Nairobi streets?