.. _ref-overview:
================
Project Overview
================
.. _ref-overview_mission:
Alterna's Mission
==================
Alterna on their mission:
Alterna is a Center for Innovation and Entrepreneurship based in
Quetzaltenango, Guatemala. Our mission is to develop technologies
and build local businesses that satisfy basic needs and provide
economic growth opportunities for the Guatemalan people in an
environmentally sustainable way.
One of their major projects are micro-hydro plants in rural areas:
Two million Guatemalans live without access to electricity. The vast
majority of these people live in rural areas. Expansion of the
national grid to the areas that are left unserved is increasingly
difficult due to geographic constraints.
Guatemala is also a country with great potential for utilization of
hydroelectric power. The extensive rainfall and mountainous terrain of
the country provide optimal conditions for generating electricity with
water power.
| http://www.alterna-la.org/en
| http://www.alterna-la.org/en/projects/microhydro
Our Mission
============
Alterna currently has no good ways to monitor how much power these
micro-hydro plants produce, because off-the-shelf systems designed for
ultra-high current environments are expensive. Measuring power
generation is useful both to understand the efficacy of these
installations and because it is prerequisite to applying for carbon
grants which can offset the costs of development. Therefore, we
prototyped a circuit based on the open-source Arduino platform which
measures single-phase AC power coming out of the installation, logs it
to an SD card, and transmits daily SMS status updates over a GSM
network. The circuit can handle household voltages (~240V), currents
up to 100A, and costs around $200 (and as little as $100 when produced
at scale).
Carbon Offsets
---------------
Becoming accredited to sell carbon offsets is not a trivial process
and having information on kWh generated is only one part of it.
Nevertheless, organizations like `ClimateTrust
`_ exist to help organizations through
the bureaucratic steps of the process, but they can't do anything
without data, so we feel confident that this device will be an
important part of offsetting micro-hydro costs with carbon offsets.
The U.S. Department of Energy Clean Energy Application Center authored
a report on selling carbon offsets, which you can read `here
`_.
Specs In More Detail
---------------------
**Intended Purpose**
* Easy to use power measurement device
* Cheap to make
* Able to monitor current and voltage on 1 phase system
* Logs data to an SD card
* GSM connectivity provides two functionality:
* Sends an SMS if the voltage drops for an extended period
* Sends a daily "power collected" SMS with the power generated during
that day
* Flexible design allows for reprogramming and hacking
**Intended Users**
* Engineering graduates and other workers with basic technology fluency.
* Designed so that it can be manufactured *relatively* easily.
**Power Measurement Specifications**
* Nominal voltage is 220V. Maximum we've seen was 225, minimum 219.
There may be brief moments (around half a second or less) when it is
much lower, down to 150V, when an extra heavy load is switched on.
* Nominal frequency is 60 Hz. Minimum 59, maximum 62.5.
* Single Phase AC.
* Current varies significantly depending on the season (water flow).
Max in the rainy season is approximately 55A. Right now it's about
30A. Dry season production may drop down as low as 15A, but we
aren't sure on that yet.