The genius of low-tech and reusable technology – Oct 6

‘Tilting at windmills: the boy who harnessed the wind’
John Vidal, The Guardian
Back in 2001 William Kamkwamba was a semi-educated 14-year-old Malawian who had been forced to drop out of secondary school when, during a terrible drought, his parents could no longer pay for him to go. This week, he has been in California and Chicago on a whirlwind book tour, hailed as a “genius” and appeared on TV chat shows. He has been the toast of international technology conferences, lauded by Al Gore and environmentalists and shared a stage with Bono and Google co‑founder Larry Page – as well as co-writing a book about his life, with journalist Bryan Mealer.

When Kamkwamba stopped going to school because his family could no longer afford the fees, he went to his local library, read up on his science, found a DIY guide to making a wind generator and set about trying to build it. Using a tractor fan, shock absorbers, PVC pipes, a bicycle frame and anything else he could lay his hands on, he then built a rudimentary wooden tower, plonked his home-made generator on the top, and eventually got one, and then four bulbs to light up. He is now known as “the boy who harnessed the wind” – the title of his book.

“I managed to teach myself about how motors and electricity worked. Another book featured windmills on the cover, and said they were used to pump water and generate power. I was so inspired I began collecting scrap metal and old bicycle and tractor pieces. Many people, including my mother, thought I was crazy,” he wrote in his blog this week…
(3 Oct 2009)

The Community Cooker Turns Rags to Riches
Sam Burcher, ISIS
The disturbing scenes of human deprivation in the highly acclaimed movies Slum Dog Millionaire and The Constant Gardener [1] show the real-life slums in India and Africa overflowing with people and with refuse. But what if the piles of stinking rubbish could be converted into what urban slums need most of all: hot water for washing, pure water for drinking and heat for cooking?

Nairobi-born architect Jim Archer has designed and implemented with the help of his Kenyan fellow Director Mumo Musuva and their Planning Systems Services team the 2008 World Architecture Festival (WAF) award-winning project in Kibera, Africa’s largest slum, which does just that. The locals in the Laini Saba district in Kibera have been instrumental to the success of the project they call the “Jiko ya Jamii,” that translates from Swahili into the “Community Cooker”…
(30 Sept 2009)
The full report is behind a pay wall -KS

Water powered cable train
KDD, Low-tech Magazine
Cable trains (or funiculars) are one of the most energy-efficient modes of transport out there. A large portion of the power required to pull up the ascending car is delivered by the counterweight of the descending car. Many historical systems used this efficiency and took it one step further with systems exclusively powered by water and gravity.

Cable trains first appeared within the second half of the 19th century. Many of them have survived and continue to be utilised (mostly in a modernized form) and new systems are being developed. A cable train system is operated on a steep slope with a gradient of up to 55 percent and consists of two passenger cars which are connected by a steel cable. Both cars travel on the same single track, which is undoubled in the middle so that they can pass each other.

Cable trains prove extremely energy efficient because a large share of the power required to pull up the ascending car is delivered by the counterweight of the descending car. Since the system only needs one track and can go straight up a mountain, it also saves a lot of materials and space (some systems use two tracks but follow the same principle). A funicular should not be confused with a cog wheel train – even though many older cable cars applied a similar mechanism, as a braking system and speed governor, not as a traction method…
(17 Sept 2009)

The Weekly Geek: micro-hydro power
bex, Greenpeace UK
(27 Feb 2008)
It’s Weekly Geek time, and this week we’re looking at micro-hydro power: a truly reliable, highly efficient, and extremely clean (it has no direct carbon emissions) way of generating electricity.

It needs no fuel but offers a constant supply of electricity which often increases in winter, along with demand. It has a long life cycle (typically 25 years or more). It can have low implementation and maintenance costs. And, unlike some large scale hydroelectric power schemes, it has minimal environmental and visual impacts.

It’s so brilliant, in fact, that the Ancient Greek Antipater of Thessalonica was prompted to write:

Hold back your hand from the mill, you rinding girls, even if the cock crow heralds the dawn, sleep on. For Demeter has imposed the labour of your hands on the nymphs, who leaping down upon the topmost part of the wheel, rotate the axle; with encircling cogs it turns the hollow weight of the Nisyrian millstones.

OK, he was talking about ancient water wheels, but the two technologies are based on pretty much identical principles (and I’ll take any opportunity to shoe-horn a bit of poetry into this column…). Water wheels have been around for millennia; Ancient Indian texts seem to refer to a water wheel being used as far back as 350 BC, although the first time we know for sure one was used was in ancient Greece and Asia Minor, around 240 BC.

…Where they’re built
Micro-hydro plants can be built in old, redundant water mills scattered around our countryside; a number of old mills are being converted because re-using structures like the weir, the leat and the original stone millhouse (to house the machinery) mean using fewer resources, less time and less money to build the plant. And because they’re pretty. Pedley Wood in Cheshire and Gants Mill in Somerset are both sited in converted mills.

Another option is to build micro-hydro plants in entirely new sites. The same considerations (flow rate and head) apply, but if a spring-fed stream has enough of a drop, new sites can be developed without the need for structures like weirs.

Either way, most micro-hydro schemes are “run-of-river”, meaning they don’t have a reservoir and only take water from the stream when there’s water available.

As concerns about climate change and fuel security grow, hydro-power is getting a fair bit of attention as a small, clean electricity source that can fit perfectly into a decentralised energy system.
An older article but packed full of good information and right on topic. We have been buying flour ground in old water wheel-driven mills and it makes some fairly wicked bread.

Also check out the Museum of Old Techniques. -KS