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Participant

Join Date: Oct 2017
Posts: 3

Portable Energy Generator for Impoverished Off-Grid Communities

10/07/2017 8:45 PM

I am a 3rd year integrated Engineering Student at UBC. For our 3rd year project we decided to make a portable generator to power laptops that were donated to an isolated off grid village in Nepal (for educational purposes). This project course has an entrepreneurial aspect to it, so as part of the design and brainstorming phase, we are reaching out to charities, subject matter experts, potential customers, and any possible relevant stakeholder to ask for their input.

The device we are making must be portable, and relatively simple and easy to fix and use (so users can fix it themselves in case of damage). It has to fit into the lifestyle of subsistence farmers who spend the whole day ploughing land with ox and other beasts, cutting and collecting firewood, collecting water from a river which is 3 km away...etc.
At night the villagers are usually around a camp fire inside their homes.

As a minimum, the total amount of energy generated must be enough to power 20 laptops for 90 min 5 days a week. Whether this is achieved by one device or by several devices collecting small amounts of energy is still to be determined. the prototype must not cost more than $500. (university funding available to us)
The forms of energy we can use range from microhydro, mechanical energy (of animals, or somehow harnessing the energy of walking from humans), solar ,or wind (both harder to fix). Other less orthodox ideas are using the fire pits that are created nightly, or the rain during monsoon season. There is no geothermal, and gas or diesel are not available (we also prefer sustainability). Also it will probably cost too much for us as students to travel to Nepal and set up a hydro generator if it involves having to change the landscape, install pipes...etc.
The villagers themselves also may not sacrifice a huge portion of their busy survival life to spend on setting up or generating power, as they are yet to "see" the full benefits of education and are trapped in a poverty subsistence life.

Any suggestions, comments, or ideas would be greatly appreciated.

  1. What are some of the ways people in remote communities produce electricity? Any innovate or unorthodox solutions you know of?
  2. How do you think we can tailor this device to solve the specific needs of the community mentioned and also be useful to other charities or even to camping enthusiasts?
  3. Do you use any similar devices ? What bothers you about them?
  4. What are some of the challenges of producing power in an off grid community that you can think of?
  5. What improvements would you like to see in your current power generators?
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Guru
Technical Fields - Technical Writing - New Member Engineering Fields - Piping Design Engineering - New Member

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#1

Re: Portable Energy Generator for impoverished off Grid communities

10/07/2017 9:49 PM

Duplicate thread alert; please go to the other one.

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Guru

Join Date: Mar 2007
Location: at the beach in Florida
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#2

Re: Portable Energy Generator for impoverished off Grid communities

10/07/2017 11:10 PM

I would go with small steam powered generators....easy to build and maintain....

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Guru
India - Member - New Member Engineering Fields - Electromechanical Engineering - New Member

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#3

Re: Portable Energy Generator for impoverished off Grid communities

10/08/2017 12:35 AM

As you wrote farmer uses Ox to plough their farm. those Oxen can be used to drive a dynamos or alternators to Charge batteries.There are people working on this idea and might have installed already some units in some other places. you may try to find those and talk to them..

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Active Contributor

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#4

Re: Portable Energy Generator for Impoverished Off Grid Communities

10/08/2017 10:59 PM

Suggest biogas pit which uses a composting process to create natural methane which can be used to run a generator. Source "fuel" is animal waste, human waste and farm/vegetative waste. A popular third world solution in agricultural areas. Plethora of info and examples on the Web on the topic.

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Guru

Join Date: Sep 2016
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#5

Re: Portable Energy Generator for Impoverished Off Grid Communities

10/09/2017 1:46 AM

May be you can do improvement on this

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Power-User

Join Date: Apr 2005
Location: Scotland
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#6

Re: Portable Energy Generator for Impoverished Off Grid Communities

10/09/2017 7:25 AM

I think Bill Gates has it sorted already!

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Guru

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#7

Re: Portable Energy Generator for Impoverished Off-Grid Communities

10/10/2017 4:09 PM

How about a Stirling engine connected to a generator. A Stirling engine contains a trapped gas that is repeatedly shuffled between a cold region and hot region. As the gas expands and contracts, the different pressure moves a piston which transports the gas and a piston which provides power.

https://www.youtube.com/watch?v=4T-uVWZR2Rc

A Stirling engine is an external combustion engine and can run on any source of heat - focused sunshine, burning plant matter, anything. It requires no refined fuels or water. It's perfect for an isolated village's power source.

http://auto.howstuffworks.com/stirling-engine.htm

https://www.youtube.com/watch?v=cVCtgB66T28

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Participant

Join Date: Oct 2017
Posts: 3
#8

Re: Portable Energy Generator for Impoverished Off-Grid Communities

11/10/2017 1:13 AM

Update:
First off, I just want to say thank you all for your contribution to our project, you've all been a huge help to us in generating ideas. Attached are some of the reports we handed in so far, if you guys are interested to read. (the interview report may contain some of your inputs. click here)

The project is moving along fine. We have ruled out using Mechanical Energy (animals, human powered), Solar, Hydro, and hydro-cell (PEM).
We are now deciding between using biomass in the form of wood, or using wind energy. (there will be a report explaining why we ruled out those things in the future)

Our second round of interview reports are due on Sunday, meaning we need your help again!

The villages that we are trying to help, unfortunately do not have enough manure, wood, or food to spare for efficient biomass energy generation. However, they do have just enough wood to maintain a fire in each household (60 households total) all day round to use for heating cooking and making tea. (they can't spare more wood to feed a burner).
There are two "designs" (not full designs, more like ideas) that are competing right now:
The first model is where we use the fire that each villager makes (in each house) to generate and store a small amount of electricity. The device we imagined (picture drawing) is a quarter sphere "chimney-stove" made of copper or some other material with high thermal conductivity. The whole outside of the "chimney-stove" will be covered with thermoelectric generators (TEG modules) to capture the waste heat. The top of the "chimney-stove" which is the hottest part (because the fire will be touching this part) will have the hot side of a b-type sterling engine. The cool side of the engine will be outside at the top, and will be cooled with a water pack or heat sink, and by the air (15 degrees C). The sterling engine turns a disk which turns a motor (or some similar arrangement to run a motor). The motor and the TEG are connected to a regulator which is connected to a battery or an appliance (depending on output power). I am currently in the process of figuring out the potential power output of this design, and would appreciate any input on how to do this (I am trying to fin the Temperature at the hot side of the sterling engine and on the outside surface of the device given a 1000 degree C fire producing 10KW heat). Also attached is a picture of a rudimentary CAD drawing of the design (the cone is the fire and the cylinder is the sterling engine, the motor and thermoelectric generators are not shown)
The second design is some kind of a Vertical Axis wind turbine. We don't have our own design for this yet but, this turbine configuration was chosen because it can better handle rough winds and doesn't need to face the wind direction. Also the gear box and motor are located at the base, which minimizes materials and maintenance. using wind speed of 10mph and a low end efficiency of 25% with this formula:
(link)
Where:
P = Power output, kilowatts
Cp = Maximum power coefficient, ranging from 0.25 to 0.45, dimension less (theoretical maximum = 0.59)
ρ = Air density, lb/ft3
A = Rotor swept area, ft2 or π D2/4 (D is the rotor diameter in ft, π = 3.1416)
V = Wind speed, mph
k = 0.000133 A constant to yield power in kilowatts. (Multiplying the above kilowatt answer by 1.340 converts it to horse- power [i.e., 1 kW = 1.340 horsepower]).
We get a power estimate of 0.01265*A (KW). so (12.65 * A) W where A is the rotor swept area in ft2.
On Tuesday (Nov. 14th) we will discuss and then decide on which road we will take as a team, using our research, and the feedback from subject matter experts (professors), potential customers (NGOs, and outdoor enthusiasts), and online forums (you guys!).
Keeping the specifications in mind (in the project proposal pdf):

  • produce 1.2kWh of power (main specification)
  • Have marketable potential (this one is not in the pdf because the pdf is for the technical course, this requirement is for the business, and engineering entrepreneurship course. Both courses are related by the same project and team) (main specification)
  • fully recharge simple electronic devices in under 12hr
  • water proof (main specification), durable, under 30kg, and easy to maintain
  • 30% locally sourced

Here is how I personally see it:
Fireplace "Chimney-Stove" Design:
Disadvantages:

  • Immediate drawback is that each household has to have one of these, which may mean that this option will be more expensive.
  • 1 device only may not produce enough power to charge all the laptop and several of these devices charging several batteries will suffer from more inefficiency. However, the details of this remain unknown because I haven't yet calculated the potential power output possible. (would love some help with that)
  • May be very heavy depending on the size and the material.
  • The sterling engine may easily break down, and I was told that it is hard to re-calibrate such a device (never built one so I don't know, anyone have any experience with this?)

Advantages:

  • If the device produces enough power, each household will have autonomy, and won't need to draw power from a centralized generator that depends on the wind, meaning each house can even light a light bulb and not rely on fire light to study. (the wind turbine will most likely only be able to power the laptops and the phones, if we aim to keep the device small and portable <30kg)
  • This is a power generation, heating, cooking, and fireplace device. It improves protection and security from fire hazards by keeping the fire contained and not open, it helps direct the heat of the fire to one side of the room (like a fireplace or chimney), it can be used as an oven or wood stove, and it simultaneously generates power while in use. I would imagine the efficiency will be very high.
  • The device is minimally invasive in the sense that, villagers do not have to spend too much energy setting it up, and don't have to significantly change their lifestyles to run it. All the villagers have to do is to continue to make a fire and cook and heat with it.
  • This device has allot more market potential than a wind generator, especially for camping enthusiasts. (depending on how big and heavy it will be) This is because of it's many functions.

Vertical Axis Wind Turbine

  • Only one big device to power the entire village.
  • Can meet power goals more easily.
  • May be too heavy.
  • will work continuously in any wind direction, so constant power generation.
  • Other than the setting up cost, time and the maintenance cost and time, this will not intrude on the lives of villagers.
  • Depending on the scale, this may make enough power to power not only laptops and phones but also lights in each household. (the trade off is size and weight of the device)

I'm a little biased here because I came up with the "Chimney-stove" design so please try to think of your own pros and cons.
Anyways, I would love to hear any suggestions comments or advice regarding our project and the next steps we should be taking now.

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