Experiments

Byron geeks out with Fog and Arduinos in Nepal

Byron geeks out with Fog and Arduinos in Nepal

We really didn’t have anything to do with this project, except for briefly loaning Byron Bignell a Arduino Duemilanove and an occasional conversation about what he was doing. The story of using inexpensive technology in a smart and efficient way for a NGO was too compelling not to share though.

It was back in 2010 that Byron first got involved with Fog Quest and the Nepal Community Development Foundation (NCDF) through his friend and fellow photographer Tony Makepeace. After some life changing events in his personal life Byron was beginning to question whether to continue to work in digital advertising or if it was time to look beyond that for something he would find fulfilling, it was then that Tony took him to Nepal.

Their trip had them staying with locals in rural Nepal while inspecting sites for installing and doing maintenance on fog collectors. Byron fell in love with the people and communities in South Eastern Nepal. He was hooked, and has been back three more times since and is planning for his fifth trip in May.

The need for the collectors in rural Nepal isn’t because Nepal lacks water, but rather that it lacks potable water. This is largely due to poor sanitation and agriculture polluting surface water. Potable water has to be trucked into many villages in barrels, which while expensive is still cheaper than building western style water treatment plants for every small town. Wells are unfortunately not an option in much of rocky and mountainous Nepal. Rain water and water collected from fog is perfectly potable without treatment though, and is a fraction of the cost and effort of treating ground water. What South Eastern Nepal has in abundance is fog particularly in the rainy season.

What does this have to do with Technology?

The fog collectors are much cheaper than water treatment facilities to build and maintain, but they still do have a cost. For example the large collector in Pathivara Nepal that Fog Quest and NCDF built with a 30,000 litre ferro-cement cistern and two 8x10m fog collectors had a total cost of $25,000 Canadian for materials and installation. Much of the engineering and labour is done by volunteers but their time and availability is limited and has to be spent just as carefully as money. This means carefully choosing the locations for the large collectors so their usefulness can be maximized. Choosing the right location for a collector means making an informed decision and for that you need information, Byron's small collector project is focused on providing that data.

There isn’t much weather data available in rural Nepal. The data that would be useful for choosing the location for a fog collector is wind velocity and humidity, which doesn't exist for many of the potential locations for fog collectors. Too much air movement could actually decrease the quantity of water collected, and too little air movement could do the same. Average Wind velocity on the side of a mountain can change dramatically within a hundred feet either horizontally or vertically depending on the terrain. The relative humidity can also change with altitude because as air is pushed up the side of a mountain it cools and contracts decreasing the total volume of water it can hold, thus increasing its relative humidity.

In the end the most effective way to predict how much water can be collected in a fog collector is to build a fog collector and measure the water collected by it, and this was the method Fog Quest used. Typically someone living close to the collector would need to be hired to hike up the mountain at least once a week to get readings from a sampling fog collector. Measurements were literally done by marking the water level in a bucket with a grease pencil, measuring the change from the last mark, and recording it in a ledger. This would be done for a minimum of about 6 months in order to get a good picture of the suitability of the site.

Manually recording measurements in this way was labour intensive, and also very often unreliable.

Being a good geek, Byron knew this was a problem that could be solved with a low power micro-controller running off a battery and a solar charger. Initially he investigated using a GPRS shield (GPRS 1.4 from Seeed Studio) to transmit the data collected on a daily basis either by SMS or digital data - but in his early tests with a small solar panel (about .25’ sq) and a 3000mA LiPo he found that the GSM shield would reliably drain the battery in about an hour. Not an insurmountable problem but given the added cost of the hardware, and cellphone account for each installation it was deemed a problem not worth solving.

In the end he used a Seeedduino Stalker v2.3 with a 2GB SD card, 3000ma LiPo battery and a 3v solar panel. He picked the Stalker because it has a charging circuit as well as a solar panel circuit on the mainboard. The Seeedduino runs on power provided by a solar panel during the day and a LiPo battery through the night. 24 hour power means data can be captured day and night, and recorded to the SD card so long as there is still storage space.

After experimenting with a variety of different sensors for measuring water flow Byron ended up using 5ml calibrated tipping rain gauges provided by Environment Canada. The Arduino records the date/time (to the second) as well as the ambient temperature for each tip of the gauge.

Byron designed a 1m/sq fog collector specifically for use with his data collection hardware. Built out of ABS pipe it uses the same woven polyethylene shade sail material that is used for larger permanent fog collectors. Its small 1m/sq size is partly because the rain gauge used can only record a flow of up to of 5ml/sec and a large collector would overwhelm it. More importantly, for the collector to be useful for sampling it needed to be reusable and portable.

Once the data collected is downloaded from the SD card the results are graphed over time and then extrapolated to determine what could be collected by the two 4x5m surfaces of a standard medium sized fog collector or from two 8x10m surfaces of a large fog collector used by fog quest.

Byron’s first prototype was built and deployed in Panchthar, Nepal, (Latitude: 27.166667 / Longitude: 87.833333) through April and May of 2013. Byron is set to return to Nepal in May of 2014 to collect the data from it and to install an updated version of the water meter.

His new and improved version uses a Netduino plus2, a 2GB SD card, charging shield with a 2 watt 6 volt panel kit from Voltaic systems. The switch to the Netduino was done partly because of Byron’s preference to C# over Arduino’s C like language.

Once the meter has proven its reliability and value as a data collection tool it will likely be rolled out on a broader basis. Byron is also involved in looking at how meters could be installed at the outflow spigots of large fog collector cisterns to measure water consumption and demand.

What I find most interesting about Byron’s work is how $100 or less worth of reusable hardware and a bit of ingenuity can be used make a difference. Not to diminish what Byron has accomplished, but the hardware exists to do things like this and it is easy to use. The potential of that is very exciting.

The technology isn’t the hard part. Finding the initiative, and imagination to use it is. Something that Byron is clearly very capable of doing.

Clayton Partridge's picture
BY: Clayton Partridge
Founding Partner

Clayton is a developer, and likes to make things out of other things.

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