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Author Archives: Charlie

Change Engineering to the rescue

pic1How do people and communities change their behavior?  We can do all the inventing we want, but if we don’t anticipate how people receive new ideas then we are probably doomed to failure.  As soon as we leave, the innovations we brought with us to a community are out the door as well.   Aid organizations and engineers working on problems have limited resources – both money and time are scarce – but the problems are innumerable so we don’t have the patience to work on things that don’t work.  If we want more successes we have to develop better implementation plans, taking into account everything we can learn about what makes people tick.

For lack of a better term I call this thought process “change engineering”, or designing and implementing new products andpic2 innovations very deliberately so that they stick when applied to a new community or market. This requires equal parts anthropology and social engineering, as well as the harder sciences to address the technology (and some things we have to make up as we go along)?  Too often our teams going to the field are made up of traditional engineers only – people trained to appreciate new products for the sake of newness only, forgetting that not everyone is like us.  But what if others value innovation differently than we do?  Our (first world) culture is famous for innovation.  I find this to be a defining characteristic of life in these modern times, but it’s different in more traditional cultures.  Imagine our distant forefathers eeking out an existence on the savannah; do we really think the serial risk taker was the one who got the most genes in the pool at the end of the day?  The more I travel I find that it is more likely that they were the ones written off as a menace to the community well being – a crackpot with the least desirable habits.

pic3Perhaps we need to try and correlate risk averse behavior with Maslow’s Hierarchy of Needs.   Maslow speculates that people strive to meet basic needs, like feeding their families, before they move on to tackle more complex ones (like saving the environment).  The ability to tolerate risk is correlated with security – represented by higher levels on the pyramid – which is distributed differently around the world.  What if people with little disposable income don’t approach risk the same way we do?   In our case we will borrow to the hilt on credit cards for consumer electronics we don’t need, then still take out a for-the-rest-of-our-life 30-year mortgage on a house. However in most other countries, borrowing is from families and spending beyond means is not taken to the extreme lengths that we see in the US.  It is widely known that people save money differently around the world, with poorer people tending to save more, but what does that mean?  Financial literature speculates that saving money is a virtuous activity and theorizes “risk averse consumers set resources aside as a precaution against possible adverse changes in income”; meanwhile our culture incorrectly assumes that our present level of income will always be there.

People may be unwilling to spend their savings on the things we think are valuable assets for them pic4because purchasing such unfamiliar goods represents an unacceptable risk.  We have to consider the implications of this mentality when we want to introduce “new things” like an improved cooking stove (perhaps saving them time and money, and improving health) that compete with the status quo – often just a simple ground stove fueled with free biomass.  The “new thing” is sometimes just too strange.  If you factor in the differences in the way people value their time – free time may not be such a luxury in much of the world– we find that even giving away useful goods for free is problematic!   Of course the key to engineering change better is in more observation.  Become an expert in your community’s problems and live life in their shoes.  Collect some firewood, start a fire with wet wood, cook a meal over a traditional three stone fire… and definitely listen.

The case for tiny wind energy

Jeremy in the belly of the wind turbine, with Nili supervising

Jeremy in the belly of the wind turbine, with Nili supervising

Editor’s note:  This is the second blog in a series related to the testing of the wind turbine at the NASA-Ames wind tunnel in Mountain View, CA.  Check out the first blog in the series for some context!

Working squeezed/scrunched up in the belly of the Army Aeroflightdynamics Directorate 7’x10’ wind tunnel gives one lots of time to think about the world and our place within it, and how these “tiny” wind generators (the term “micro” has already been claimed for systems up to 5000 watts) can help contribute to an improved quality of life for some.  Remember the target market is people who either have zero access to electricity, or who perhaps depend on charging worn out car batteries in distant grid connected towns – you pay bus drivers to transport your battery back and forth – to get a trickle of power.  How people use that first few watt-hours of high quality energy they have access to fascinates me, since while we sometimes have an impression that everyone else wastes scarce resources too, in reality people with scarcity tend to know the value of conservation and wise use best – especially when their costs are high.

Extending their day by a few hours with an efficient light is usually the first use – most unconnected places seem to be close to the equator where the days are always short, and recurring costs for candle/kerosene lighting are cumbersome/prohibitive – allowing people to read, do homework, and maybe even earn extra income.  Charging batteries – for flashlights, the radios all campesinos carry to the fields, and cell phones – is another priority, hopefully reducing the number of discarded disposable ones that litter the ground.  Both of these applications require very little energy – for us it would be worth just pennies worth a day, but for people who all year around are used to calling 6 pm bedtime… priceless!  And yes, one of the first appliances to appear is the ubiquitous television, often for soap operas and soccer matches, but also news and education.

Charlie investigating Chinese instream picohydro generators (~30 watts) in a Vietnamese market

Charlie investigating Chinese instream picohydro generators (~30 watts) in a Vietnamese market

Just a hundred watt-hours a day will do all kinds of things when the appliances are efficient, and in a breezy location it shouldn’t take an expensive turbine to provide this.  As a slightly technical aside, it is best to remember that people use energy to do things while we have a tendency to express the output of wind generators (and photovoltaic panels, and microhydro installations, and nuclear power plants) in units of power (watts).  The wind tunnel tells us how many watts we might generate at a given wind speed, but winds fluctuate so we can’t count on getting that much all of the time.  Commercial turbines are almost invariably rated just in watts, and you always have to ask “At what wind speed?” – and you’ll quickly find that they choose to rate at some phenomenal (and usually unrealistic) value, like 25 miles/hour (~11 meters/sec).  Southwest Windpower has now started doing the right thing by helping you estimate how much energy (in watt-hours… each one of these helping to perform a useful task, such as a one watt LED lamp aiding a kid do homework for one hour) you might expect to generate from their products, after making some assumptions about your local wind speed distribution.

This brings us to the question “How do we extract power (and energy) from the wind – which comes originally from the sun?”  The maximum power available from the wind, per square meter of turbine swept area, can be easily calculated from the equation

Power = ½ rAV3

where r is the density of air, A is the swept area of the turbine, and we see that the power increases as the cube of the windspeed (doubling the windspeed gives 8 times as much power), so that while there is lots of power produced at high wind speeds there is almost none available at very low speeds.  Our Lenz blades sweep out an area of .75 m2 (the Savonius configuration we tested is .45 m2) and we know that we can only realistically have a fraction of the energy the wind contains – Albert Benz said that 59% is the maximum, but more like 30-40% is typical for small tubines like ours.  So the amount of power you can tap into depends on how much the wind blows, and with like so many other things (like per capita income) the averages provided to us by the government don’t always do us enough good – some days it doesn’t blow, some days it blows too much, and luckily some days it blows just enough for your turbine to fill up your batteries for the

Weibull distribution (wind speed vs. probability) for an average wind speed of  6.6 m/s and a shape factor of 2.

Weibull distribution (wind speed vs. probability) for an average wind speed of 6.6 m/s and a shape factor of 2.

coming week.  That’s the concept of the distribution (vs. and average), and luckily the wind speed variability tends to follow a Weibull distribution, a statistical function, where just two variables describe the distribution.  These are the average wind speed and a number related to the general amount of time with no or low winds (the shape parameter), and this site does a much better job of explaining it than I can here – and they allow you to type in your power vs. wind speed data (such as from wind tunnel testing), plug in a shape factor, and get the anticipated energy output (say in watt-hours/day) at your target location.  Now you can buy the right number of storage batteries to get you through the wind-less doldrums, and compare the cost of your tiny wind system with your other electricity alternatives – including continuing to charge your car battery for the equivalent of $3/kW-hr, and waiting a long time for the grid to arrive.

Maximum power vs. wind speed of the Lenz 2 turbine configuration

Maximum power vs. wind speed of the Lenz 2 turbine configuration

Taking the raw wind tunnel data Tyler showed (torque and power vs. RPM) we can determine the maximum amount of power a given blade set or configuration can extract from the wind at each speed and plot it – that upward curved shape is very important because it tells us that not much power is available to us at low wind speeds (say, <10 mph) and this is an unfortunate fact of life.  Our experimental method did not include a generator to turn the winds power into the electrical power we need to run appliances, and there will be losses in this conversion process – we expect it to be ~75% efficient – so we have to take this into account, giving us the ability to get about 25% of the energy embodied in the wind – not bad if the resource is free.

As mentioned, a single “power rating” for a turbine is not very useful (and only meaningful if the wind speed it was measured at is associated with it), but people are used to hearing just one number so we may need one.  Catapult Design will tend to rate these turbines (a set of blades plus the associated generator) at more realistic wind speed values, like 15 mph (7 m/sec), and then we’ll do our best to try and characterize the wind resource at a specific locale.  If we choose to rate at 15 mph, for example, then the real power output of the Lenz blades is ~30 watts, and the wind will need to blow at that particular speed for ~3.5 hours/day to provide 100 watt-hours of energy per day to a family or small business.  Blowing at half that speed for twice as many hours does not do us much good, since the blades of VAWTs often don’t start turning until 8 mph, and at 10 mph we might have to rate these tiny turbines at only a watt or 3.  For estimation purposes, Weibull wind speed distributions with very low shape parameter values would be an example where it blows very little, much of the time.

blog5Its unfortunate that life is never as simple as it needs to be – it seems like that if a family wanted to consider buying a tiny turbine at X dollars, to decide whether it is worth it they need that power performance curve for it, decent information on their local wind conditions, and some idea how much electricity is worth to them (for example based on how much they are presently using and the cost for charging that car battery, or how much more they want to use – say if their neighbors pay them for charging cell phones).  Now if we just knew the probable lifetime and annual maintenance costs we could start to understand the cost of each future watt-hour… what an exercise, and don’t forget that investing in all forms of renewable energy is tantamount to buying at one time all the electricity you will use for the rest of your life, which is not an easy decision to make.

Determining Need

Photo by Chris Seewald, Stanford Daily

Photo by Chris Seewald, Stanford Daily

Several of us recently visited Stanford for a panel discussion on “Clean Energy in the Developing World”, featuring the former president of Peru and touching on such important topics as clean cooking stoves and distributed power.  While I applaud any attempt to educate people about the needs of the developing world, why do we feel compelled to dazzle each other with unimaginably huge and depressing numbers when describing what we are up against?  When repeatedly told that “billions” are prevented from realizing their full potential for one reason or another we can’t help but be overwhelmed – and that doesn’t necessarily help.  Often there is not consensus on some of these figures, and even the definitions are not clear – for example poverty is often defined as <$1 per person per day, other times <$2/day, and most recently the World Bank has established <$1.25/day as the new magic number for extreme poverty and says that 1.4 billion people are in that particular situation.

What really does measure a population’s quality of life best, so that we can use appropriate metrics to determine our path and then see our progress?  I believe that each and every family and community has a different combination of circumstances, and most would object to being lumped into a huge group and worldmapcharacterized as hopelessly impoverished – that term they usually reserve for someone else, less fortunate than they are.  Too often we rush to associate quality of life with those things that we are used to and value in our own lives, rather than listen more so that we can understand local situations.  In the developed world, where cash is at the root of most transactions, we seem to need a constant flow of it to pay off the house, buy new cars, purchase food grown in distant lands, insure ourselves against unlikely calamity, pay taxes, put something aside for future expenses…ad infinitum.  In other situations low income is not necessarily the end of the world – if only because most of these families also don’t have the consumptive lifestyle and associated debt that we do.  The Kingdom of Bhutan wisely chooses to measure Gross National Happiness instead of depend on GNP as its measure of success and it considers itself to be a wealthy place – while conventional metrics might suggest that NGOs should be rushing there to “help” (50% of the population live under $2/day), I don’t imagine that most would be very welcome.  Do even the more general Human Development Indices measure the right thing – since they place Bhutan in 131st place, just barely above the seriously challenged Myanmar?  In general, can any distantly assigned artificially constructed single number ever hope to get it right?

solarSince one of the speakers had good experience in photovoltaics (PV), their application in developing countries was highlighted – it is commonly estimated that 1.6 billion people are without “access to electricity”, though this phrase is never defined.  Too often we see that communities may be characterized as suffering because they are not connected to a full blown electrical grid, when I have seen that the first little bit of electricity is by far the most valuable and appreciated – used to provide light to extend the day for doing homework, power health clinics, provide access to information via radio, charge cellphones, and more.  I consider distributed PV energy sources to be a good way to introduce people to the path of high quality flexible energy, and have worked with a tiny village (in Peru, as a matter of fact) where we use PV to charge LED lantern batteries and power some community services – just a few watts of generating capacity per family makes all of the difference in the world, and the cost of supplying this much keeps going down (while the cost of big electrical infrastructure projects keeps going up).

Access to clean water is another one of the ways we measure quality of life in communities, and just a few charitywaterdays later I attended another talk, this one at the SF Apple retail store, given by the founder of Charity: Water.

Their mission is to provide water security to people (~1.1 billion is the usual count of those without) by drilling wells – and they go about it in a very no nonsense way that depends very little on the abuse of huge numbers.  Among other things it is the tools they use that impress me – they employ superb design and marketing methods to tap into giving population segments that may have become alienated by the stale world of charity-as-we-know-it… lots of intimidating global needs represented by staggering statistics and manipulative images, ample doses of guilt, plenty of large NGO salaries, and in the long run not much to show for it all after the foreigners have gone home.

They believe strongly in transparency – how do we know that the money we donate goes where it is needed and then, hopefully, makes the long term changes promised? – and they effectively use the media and popular networking technologies like Google Earth and Twitter (and anything/everything else that you can imagine) to alert their target audience to the need and their impact on it in very effective ways.  So how do they measure up?  It takes time to tell, but 1,247 wells drilled is not a bad start at all – making steady progress a community at a time.

Lacking reliable metrics for need, how then do we decide what we can realistically do?  Perhaps rather than intimidate each other with unfathomable numbers, leading us to set vast and unrealistic goals for the developing world, we can help people set their own priorities, community-by-community, and then politely offer our assistance.

Catapult prepares for Extreme Coaching at Stanford

dschool_wrkshpSaturday several of us visited Stanford University to attend a workshop preparing us for mentoring the Entrepreneurial Design for Extreme Affordability course (there was a great article on it in Fortune last week – what a fantastic experience!  The class is part of Stanford’s d.School and incorporates graduate students from the Graduate School of Business, Engineering, Product Design, etc.   Many of the students are just back from (and recovering from) their needfinding visits to various developing countries like Rwanda and Myanmar – they were exploring what products they might introduce to improve the quality of life there, and perhaps making a profit from marketing these, if that makes sense.  We mentors exercised out listening and empathy skills by interviewing ourselves about, imagining, prototyping, and refining… oral hygiene solutions – you never know what it is that people in another culture will value as an addition to their lives, so it didn’t really matter what we practiced on.

I look forward to seeing how they develop new metrics to see how one design is more appropriate than another – letting the predict future success potential with their customers; all consumers have choices, how do we know that they will chose the ones we develop?  Looking forward to working with our faculty of Erica Estrada, a former class participant and co-founder of D.light Design, and Prof. Jim Patell.

Catapult lunches with Paul Polak, Jim Taylor

Paul Polak signs his book for students; Charlie talks with Jim Taylor, the Director of IDE-Myanmar

Paul Polak signs his book for students; Charlie talks with Jim Taylor, the Director of IDE-Myanmar

Heather and I had the pleasure to see Paul Polak speak at Stanford University – he and his effort have been one of our role models, because of his experience and bottom up approach, and the way he helps local people identify what they value enough to often save money for.  He is particularly interested in the poorest one billion people (<$USD 1/day), especially farmers, with a philosophy that if you can increase income then people themselves know how to make their lives better.  He used examples from around the world on how he has found opportunities to work with people on generating more cash flow – I have also seen that people don’t always see ways that we may find obvious for being efficient, since their culture may have no experience (I call this “technology transfer” – moving key appropriate and low tech concepts around the world).  Cabbage farming, diary/milk production, water storage, treadle water pumps, and all kinds of other things – he walks the talk!  He has some good rules for what to do and what not to do – just summarized here:

  • DO visit individual houses and talk for hours with real people about how they live, and what they think and know
  • DO listen to them with all of your ability
  • DO become an expert on what their issues are, and ask them enough hard questions

His larger list when you come into a new area is his “12 steps to practical problem solving” – buy his book!  He also has his “don’t bother trilogy” – listen to 25 people for several hours each, make sure the return on investment is not more than one year (and 300% is better), and sell a million (for a profit – full market price and no subsidies).

Paul is pleasantly opinionated, and he does not pretend that his approach works for everything – but it does for plenty of things (including aspects of hunger and education, as Maslow points out, people will not advance their lives like they want unless they can first feed their families, then plan for the next generation to have more choices).  Other models for development include William Easterly’s (The White Man’s Burden), Jeffrey Sach’s (The End of Poverty), using animals to promote sustainable wealth (Heifer.org), and the Bottom of the Pyramid movement (BOP – NextBillion.net) – none are right or wrong for all circumstances, and there are a hundred other ones, so learn about as many as you can and then mix and match!  But who can argue about all of us spending more time listening to the end customers, in their homes? Personally, I cook and build stoves in individual homes just a way to visit them for hours (I sharpen knives while talking – why else would they have me that long?) and learn about more than just cooking – what do they value?

Designing Rural PV Sytems that Last

solar

All around the world small PV systems have been installed to provide basic services for communities – emergency phones, lighting for key buildings, battery charging stations, health clinics, etc. – and an unfortunate number of these are no longer operational, are not presently in good condition, or are doomed in the near future particularly because of either poor original design or some kind of neglect.  For example, USAID notes that 37% of PV equipped clinics in Rwanda have solar components that are not functioning, and around the world too many others are dysfunctional for a wide variety of reasons.  Catapult Design uses an graphapproach that can make future systems more robust and user friendly, or for existing sites it is possible to revitalize them and put them back on the right track so that they meet the local requirements.

Some of the problems we see out there are due to poorly specified or installed systems, shoddy parts, lack of component and system documentation, and inadequate maintenance information (particularly for the local cultural situation) – and there is generally a difficult time expanding existing equipment when the need arises.  We are presently assisting The Ihangane Project, who work with several rural health clinics in Rwanda – some of which presently have some solar systems which need expansion and several which need new capabilities.  Our goal is to better understand how they use (or plan to use) electricity, then help them work with potential vendors so that they can create a situation that they are comfortable with and confident in – its not just about providing the technology, its about anticipating the future and working to put a whole tailored infrastructure into place that isn’t going to fail on them when they need it most.

Thanks to Green Empowerment for the Excel tools!

ETHOS 2009 Developing World Cooking Stove Conference

ethosThis was my third ETHOS (Engineers in Technical and Humanitarian Opportunities of Service – a long name for people who often just call themselves “stovers”), and the Seattle suburbs are as cold as usual at this time of year.  ~100 researchers came from around the world to compare notes on stove projects, stove designs, standards and testing procedures, health impacts, other associated appropriate technologies, and so on.  More apparent this year was interest in carbon credit funding and biochar (terra preta) applications, and all year long there has been an increased emphasis on refugee camp stoves (and more testing of stoves in the field, versus in the laboratory) so this was more apparent at the conference. 

There was a raft of new stoves introduced this year, including a new thermoelectric-powered-fan one for camping and more, the likewise fan powered LuciaStove from WorldStove , and the souped up Peko Pe natural draft gasifier (pictured with Crispin Pemberton-Pigott, wielding his ever present combustion analyzer).  The venerable Dr. Larry Winiarski and Dean Still are also shown here with the upcoming finned pot atop StoveTec’s rocket stove – now 36,000 strong in the field just since last year.  The trend toward stove models like all these, designed for mass manufacturing, continues, and this trend was recently discussed here.  And yours truly demonstrated in light snow the new biomass gasifier (the red one) from All Power Labs here in Berkeley.  Look soon for Peter Scott’s new rocket stove design and application website.