Rainwater Harvesting Research

This blog post is dedicated to research that Sylvia and I did on improving Grupo Fenix's Centro Solar (Solar Center) rainwater harvesting system in Nicaragua.

The objectives of this project are multi-faceted: Grupo Fenix wants to make use of natural resources available in their community, increase water availability by improving the harvesting system of rainwater (especially water availability for their recently opened eco-restaurant), and create a plan/design that can be integrated into the already existing Centro Solar buildings.

Because Sylvia and I do not (yet) have information as to the existing system of rainwater harvest for the Grupo Fenix's buildings, we were unable to come up with legitimate "improvements" during class. Instead, we spent the majority of class familiarizing ourselves with the written material and designs generally used. I read a number of articles (links below) to familiarize with existing literature and theories about varying harvest methods, and we came up with a number of questions for our contact person.

Before I continue with the notes taken, I should include that Sylvia and I are trying to be conscious of 1) improving on existing infrastructure (we imagine this will be the most cost and resource-efficient); 2) cost (our hypothesis is that a low-cost solution will probably be more favorably looked upon than a high-cost solution); 3) coming up with a system that provides at least decent quality water (for example, my research led me to learn that metal roofs produce higher quality water than do asbestos, tile, or thatch roofs).

Now, onto the research:

The image below is what the most common (and low-cost, we think?) rainwater harvesting system looks like. The roof is used as the catchment area and water runs off into the gutter, which connects to a pipe, which leads the water into a storage reservoir. The storage reservoir can work in two ways: the way shown below has the storage reservoir with an outlet tap, where people can gather the water from; another way we came across is for the reservoir to lead to an underground tank--which seems to allow for a greater volume of water to be stored.



Our initial impression is that this (most common) system is what would work best, and we have brainstormed the possibility of adding on another 2-3 storage reservoirs. This would prevent any flooding and would allow Grupo Fenix to capture more water. Because we have little (or, really no) idea as to what the current system looks like this is sort of where our brainstorming concluded.

With all this said, we are planning to email the Project Development Advisor at Grupo Fenix with our questions. Our initial questions are:

• What is the current design? Can we get a diagram or photo of the system?
• What specific parts of the current design seem to be the most problematic? 
• Is the storage tank above ground or below ground?
• What materials/resource do you use for each part of the system? Which materials/resources are available to you?
• Are there specific improvements you/Grupo Fenix have in mind? If so, what are they?
• Should we consider adding/improving on any existing filtration/reuse components of the current system?
• Are there any other factors that are most important to you?

Once we hear back from the Project Advisor we will have much more information and be able to come up with a better idea of how the future of this project might look!



Random notes/links from in-class research:
Thoughts/Questions -->
Need improved design (more efficient/effective system) for harvesting

What is the current design? Can we get a diagram or photo of the system?
Is the storage tank above ground or below ground?
What materials/resource do you use for each part of the system? Which materials/resources are available to you?
But also, won't we need to brainstorm a filtration and reuse system? Especially if for an eco restaurant?

Possible designs:
Gutter off of rooftop connected to piping connected to buckets
Watertronics? Based out of WI – http://www.waterworld.com/articles/2009/12/report-focuses-on.html
Similarly - "SkyHarvester" http://www.skyharvester.com/ (never mind, no designs actually published)

http://www.atlantiscorp.com.au/rainwater-harvesting/our-values/rainwater-harvesting-underground-water-tanks-re-use-tank

IETC: Connected to UNEP
http://www.unep.org/ietc/


Good reports:
General rainwater harvesting - http://www.climatetechwiki.org/content/rainwater-harvesting
Rooftop harvesting - http://www.climatetechwiki.org/content/rainwater-harvesting-rooftops
Ground harvesting - http://www.climatetechwiki.org/content/rainwater-harvesting-ground-surfaces

http://www2.warwick.ac.uk/fac/sci/eng/research/civil/crg/dtu-old/pubs/reviewed/rwh/tht_ircsa_2003/thomas.pdf
Metal roofs produce better (higher quality) water than asbestos or tile ones, thatch roofs too
"Lowering the nutrient levels of tank water –– by pre-entry screening, filtering, or first-flush diversion –– accelerates the rate of bacterial die-off and of course larger tanks generate cleaner water than do small ones."

Keychains and Power Tools!

Our class spent making keychains (Friday the 11th) was made quite exciting because it was our first time using power tools!
First, Larry and Amy each talked us through the safety and best practices for using the drill press and the band saw, and also shared some horror stories that I will spare this audience from reading. (Bottom line, never work alone, always know where your hands are, and you can never be too cautious.) Then we were given a block piece of aluminum and were asked to make sketches of our designs for the keychains. My sketch is below, but the summary is that I wanted to keep it simple in the sense that I wouldn't have any rounded edges, but also I wanted to challenge myself and have to make a lot of cuts (and make a lot of measurements to try and get it symmetrical). SO, I settled on making a star!

The challenge of the band saw was that it's a bit hard to maneuver and you can only cut straight lines, so it's a little time intensive if you have a fancy design. I was trying to make a star and I wouldn't say it turned out perfectly, but with Larry's help I did complete it! Using the drill press to make the hole for the ring was pretty straightforward; the only challenge was moving it quickly enough but not too deep so that the aluminum didn't whir and fly around. It's a tricky maneuver, but with Larry's help (and his assistant whose name I can't remember!) this part was completed quickly.

Afterward I sanded the sides of my star and then it was done! Picture is below. This was a pretty painless and fun first assignment with these power tools, and I feel much less anxious about using them now than I felt at the beginning of class!

Class By Candle

This activity really effectively demonstrated how much we take for granted light. As we tried to squint enough to be able to read the tiny print on our quizzes we all felt our eyes getting tired and our focus being strained, as it was really difficult to think clearly when having to give so much energy to just reading. We moved much more slowly and less efficiently, and really the pace of the classroom was slowed down. Though the LED lanterns added some light, they were still not adequate enough to let us think or move at the usual pace we are accustomed to.

Throughout much of this class––but especially during this experience––I have been reminded of living in Guatemala for four months. For part of my time I traveled to a school in mountains near a city called Xela and slept in the school but joined a Guatemalan family in a small village near the school in their home for meals. This family didn't have electricity and their house consisted of sheet metal siding and a dirt floor, and the light that they had came when they opened the door. They seemed to be "getting by" and still able to cook and clean, but I was never there after the sun went down and I don't think I even thought about how they would be affected by the lack of lighting. I am still figuring out how to process the difficulties posed to a life without electricity, and I'm really grateful we did this activity, as it has made me reflect even more on my past experiences (and the life I was born into and continue to be fortunate enough to live in).

The Birdhouse (aka our Sharps Container)

We had a great time making our sharps container! We drew up some initial sketches of types of containers (some more complicated than the others) but we finally decided we wanted to make it as simple as possible. The qualities most important to us were: simplicity of design and use, ease of user-understanding, effectiveness at containing the sharps and keeping people safe from the sharps deposited, and cheapness (ability to make something using classroom materials).

We also wanted it to be big enough that it was noticeable but small enough that it could be easily transported around a classroom. Above is our first design! It was a 6 in x 3 in x 1 in rectangular box made of cardboard, with a 1 in slot for depositing sharps. Below is the protoype we built using this design.

 

Tis a gift to be simple! We just used leftover cardboard and ductape with this initial design.

 

Happy with the first prototype we wanted to continue with a similar design, but we found nicer white cardboard and decided we should have it standing tall so that it would be more noticeable. We considered the fact that sharp objects can come in a variety of shapes and sizes, and thought that having an opening flap might allow for more flexibility of use (i.e. big sharp objects could be dropped in) and so we changed our design slightly to what is shown below. Because we had a new aspect to the design (a flap that opens and closes) we wanted to ensure that it could be secured closed, and so we added the little green string and the cardboard circular peg. Hot glue became our best friend during this project!

Front view of our sharps container . . . "The Birdhouse" :) (We hadn't yet added the pink post-it note warnings)

We tested this design with paper clips, hypothesizing that paper clips were probably as thin as (or thinner than) a sharp object could be, and so we tried shaking the container up and down with paper clips inside to see if they flew out. They did! They slipped through the slats on the side of the top where the flap was, so we added bubble wrap on the edges of the top to keep everything enclosed. This worked well, and we were happy with our final product! The finishing touch was to add hot pink post-it notes so that we could warn people about the use of the container––although I think (after having gotten feedback from the class) we would have drawn pictures instead of writing words, so that it could be (nearly) universally understood.

Above is an aerial view of our final, final product! We had a lot of fun designing this, and feel pretty good about its potential for use in the classroom.

LED Lantern

The LED Lantern project was great fun and allowed for creativity and a better understanding of the mechanics of closed circuit systems. I was initially overwhelmed by having to figure out how to put the three pieces together (the battery, the little LED lightbulb, the resistor), but when looking at the simple sketch of the connection between them it started to make more sense. I am grateful, also, for my classmates as a number of us worked in there one evening and offered ideas, suggestions and creative inspiration.

First, of course, we had to calculate the proper resistor amount, and so we used the equation: R = V/I
We had the values: 9 volt battery, LED = 3.6 volts, and 20 mA current. I calculated that I would need a 270 Ohm resistor.

I wanted to go for the "traditional" lantern look (with the handle that you carry and the enclosed lantern hangs below), so I found a plastic cup and once I figured out the battery system I was able to glue the battery onto a circular piece of cardboard. I enclosed this piece with the plastic cup, and then punched (or, more realistically, slowly carved with scissors . . . ) a hole in the side of the plastic cup where the wire for the switch could poke out. Finally, I punched holes in two sides of the cup so that I could attach the handle (and double secured with tape – no one wants a handle coming off!)

And voila! This is my lantern.
 

As you can see, the clip outside the cup is used as a handle to control the little piece of wire that clicks in to the battery (to turn it on) or to move the wire away from the battery (to "open" up the circuit system, so that the light turns off). I remain puzzled by how I could have made a more "official" looking switch, but I think it's intuitive to operate––which is what my preference would be if I had to pick between these two qualities! This was a really great project, and I am pretty proud to have been successful in my creation! It would be fun to do this with friends before heading out on a camping trip :)

Time Management

I am really good at leaving things to the last minute and then getting them as efficiently as possible––as in, done minutes before the deadline! Though this is a skill that I am proud of, I also realize that my laid-back attitude will, at some point, bite me in the butt. Which is why I decided that this class––which in a number of ways (me, an engineer?) is already far different from what I'd usually take––would be my great attempt at ensuring I started projects with enough time to give test runs and fail and have to restart (i.e. what Amy said we should try to do as engineers).

Which brings me to the sharps container and lantern projects!

The sharps container group project went great and I think that's the beauty of having teammates who will hold you accountable to working collectively. I really enjoy teams (as I mentioned I am on the crew team) because of this very component of cooperation––it is absolutely a huge factor as to why the crew team has been so successful, and why I think our sharps container was a success. We started early enough after the class it was assigned and seemed to all be on the same page as to how simple we wanted our design to be. We collaborated very well together and had some great brainstorming sessions when the container didn't work exactly how we wanted it to. Finally, we all seemed to be OK with it not being or looking "perfect" (which is something I really appreciated, because though I am detail-oriented, I have a number of other priorities before perfectionism). All in all we had fun together, worked efficiently, and planned well-enough to be done several days early!

My lantern experience also worked well, as I had an image in my head (of a typical old-fashioned lantern) after several days of pondering the project, and also because we had class time to figure out the proper resistor. While working on the sharps project I got a sense of the materials around the classroom that I wanted to use for my lantern, which cut down on the time I had to spend when I arrived to work on it. I was able to complete the project in one period of time in the classroom, but I do wish I had given myself a little bit longer to think about how the switch would operate. This is a function of my lantern that I would still want to improve, but that I am still uncertain how I would improve it.

The final parts of these projects were the blog posts and I must say that I fared better on making the projects than completing the posts. As they stand, they are still only partially completed. This is one-part procrastination, one-part because this week got hectic with the start of our crew season early morning wake-ups (and thus the chronic state of fatigue until my body/mind adjust to having to shut off around 8 pm), and the final part because I had in my mind that the deadline for all the posts was today (Friday). On that front, I fully admit that they are several days overdue and I will ensure that all future posts are submitted (at least hours) earlier than the deadline.

Post 2: Poor people's energy outlook

While reading I was struck by how much of a multifaceted issue lack of energy systems is for poor households. When I think of a household lacking electricity or efficient cooking mechanisms (stoves, lights, etc.), for example, my mind primarily jumps to the decreased efficiency the situation would create, and to the necessary reliance on extra resources the family would experience. Of course, though, this would also be an issue interconnected with health, education and environmentalism. If a family is without a low-carbon cooking device, then they run a much greater risk of contracting pneumonia or other lung diseases. Without a light in the house, there is a huge risk of injury and reduced efficiency past sunset. In my life these technological innovations have been so second-nature that I have been so privileged enough to forget about the life-or-death component of their existence! Overall, the issue of energy serves as an excellent first example for a fairly simple concept, but one that my social-science mind is not always conscious of: that engineering––though maybe confused as a way to answer questions of utility, construction, science/technology, etc.––is a necessary tool to answer social issues.