CoolBot CoolRoom: The Solar Array Construction

CoolBot group members Mike and
Daniel with faculty collaborator
and D-Lab instructor

 Henceforth known as the D-Lab CoolBot group, Ariana Rundquist, Daniel Sheeter, Wu Jingyan (Dora), and Michael Cunningham decided to address the most pressing problem for the Uganda CoolBot Coolroom project: the large up-front cost of a solar array. 

 Mike Cunningham working
on inverter

In collaboration with Horticulture Collaborative Research Support Program (Hort CRSP), the D-Lab CoolBot group set about assembling a model standalone photovoltaic array in order to power the demonstrative CoolBot Coolroom at the UC Davis Student Farm.

Ariana and Mike assembling solar
 array with faculty collaborator

The array consists of the following: four 220 volt solar panels, four wooden frames built by Dr. Michael Reid, four 6 volt deep cycle batteries in series, and a control board. The control board, that is, a breaker panel and charge controller, an inverter and a plug outlet to the AC load (the air conditioner and CoolBot) was assembled by Dr. Reid and Ariana Rundquist on April 15^th.

CoolBot group installs
solar array

Ariana, Sheeter and Mike all helped assemble and successfully connect the photovoltaic array to the CoolBot Coolroom on April 18^th and 19^th, just in time for a visit from the touring Hort CRSP conference!

-- 
Ariana Rundquist, D-Lab Student 

International Agricultural Development 

Graduate Group
University of California in Davis

CoolBot Coolrooms: D-Lab Demo Site in Uganda

Anikua's pigeon peas from her
garden in Pajulu, Uganda

Refrigeration is key to the successful marketing of perishable items. The fresh produce and floriculture industries of the developing world depend on low temperatures to reduce water loss, slow the development and incidence of postharvest diseases, and limit responses to ethylene and other metabolic changes which reduce shelf-life.

Anikua's cabbage in Pajulu, Uganda

Temperature control is even more critical for the production of fresh produce in the developing world, where ambient temperatures often are above 30°C, resulting in deterioration rates more than 20 times those at 0°C (the proper storage temperature for many high value horticultural crops).

Quality can quickly decrease in fresh fruits and vegetables once they are harvested. If not carefully handled and stored properly then nutrient content is reduced along with shelf-life, or how long the product lasts before becoming inedible.  

Building storage "cooling" room
in Pajulu, Uganda

Economically, as much as 40-70% of fresh product is lost in the developing world due to post-harvest issues such as physical damage, disease, and improper handling. Temperature management is a key tool for reducing such loss of perishable food crops and maintaining nutritive quality.

However very few smallholder farmers have access to cooling or cool storage facilities, and even refrigerated transportation is a rarity. For resource-limited farmers in the developing world, cool-rooms and transportation systems employing mechanical refrigeration are economically and practically infeasible.

Demo of CoolBot System

In February 2010, the Horticulture Collaborative Research and Support Program (Hort CRSP) funded several “Pilot Projects” towards "reducing poverty, improving nutrition and health, and improving sustainability and profitability through horticulture." One of these one-year, ready to implement, and innovative projects to be tested in developing nations was the CoolBot Coolroom system. This system uses a well-insulated room and an intelligent thermostat device called the “CoolBot” (Store it Cold Ltd.) controlling a standard, wall-mounted air conditioning unit, tin order to create cheap and effective cold storage for small-scale, resource-poor farmers.

D-Lab student Ariana Rundquist
opens Coolbot storage room

Michael Reid, professor emeritus at UC Davis (UCD) University, is one of two Principle Investigators working from UCD with in-country collaborators in India, Honduras, and Uganda. Reach Your Destiny Consult was the on-the-ground partner in Uganda, and the in-country Principle Investigator (the representative from Reach Your Destiny Consult) is Gloria Androa, a former International Agricultural Development (IAD) graduate student at UCD. Ariana Rundquist, a current IAD graduate student and a D-lab student, was recruited as a Research Assistant for the project. These three members approached the D-lab at UC Davis in the Fall of 2010, hoping for an economic feasibility assessment of the implementation of the CoolBot Coolroom System in a small village of Arua District, Uganda.

Wrapping heater for temp
sensor of AC unit

Here are pictures of two demonstrative CoolBot Coolrooms, one built in 2010 here at the UCD student farm and one built in 2011 at Yabiavoko village, Ombokoro Parish in Manibe Sub-County, Arua district. 6 km from Arua town, which is 540 km from Kampala city.

--
Ariana Rundquist, D-Lab Student, International Agricultural Development Graduate Group
University of California in Davis



Demonstration coolroom awaiting insulation and roof in Uganda