Grantee Research Project Results

2010 Progress Report: Smoothing the Peaks: GridShare Smart Grid Technology to Reduce Brownouts on Micro-hydroelectric Mini-grids in Bhutan

EPA Grant Number: SU834749
Title: Smoothing the Peaks: GridShare Smart Grid Technology to Reduce Brownouts on Micro-hydroelectric Mini-grids in Bhutan
Investigators: Jacobson, Arne E. , Lehman, Peter , Cashman, Eileen , Palmer, Kyle , Chase, Nathan , Robinson, James , Quetchenbach, Tom , Harper, Meg , Mielke, Kirstin
Institution: Humboldt State University
EPA Project Officer: Page, Angela
Phase: II
Project Period: May 19, 2010 through August 18, 2012
Project Period Covered by this Report: May 19, 2010 through May 18,2011
Project Amount: $74,899
RFA: P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet - Phase 2 (2010) Recipients Lists
Research Category: Pollution Prevention/Sustainable Development , P3 Challenge Area - Air Quality , P3 Awards , Sustainable and Healthy Communities

Objective:

Village scale micro-hydroelectric systems in countries like Bhutan, Thailand, Peru, Laos and China provide renewable electricity to thousands of self-reliant communities in remote locations. While promising, many of these systems are plagued by a common problem: brownouts occur frequently in the mornings and evenings during times of peak demand (Figure 1). The lowered voltage that characterizes a brownout causes lights to dim, televisions to flicker and electrical appliances not to work properly. These technical failings result in residents switching back to fuel-based cooking methods and losing confidence in the reliability of the electricity service. If demand could be distributed more evenly throughout the day, these systems could provide reliable, long-term renewable electricity to these communities.

Figure 1. Voltage and current on one phase of load output at the powerhouse in Rukubji, Bhutan on July 19th, 2010. The periodic increases in current and corresponding decreases in voltage represent the morning and evening brownouts that are characteristic of micro-hydroelectric mini-grids in Bhutan and elsewhere around the world (L). Typical cooking appliances in Rukubji, Bhutan include water boilers, rice cookers, curry cookers and LPG stoves (R).^[1]

In Bhutan and many other countries, brownouts have been linked to the use of electric cooking appliances such as rice cookers and water boilers (Figure 1). In his research on micro-hydroelectric minigrids in Bhutan, Karma P. Dorji suggested that brownouts could be mitigated by distributing the use of these appliances more evenly throughout the day (Dorji 2007). For example, rice cookers often draw 600-1,000 watts when cooking the rice, but less than 100 watts to keep it warm. Therefore rice that is cooked near mid-day can be kept warm until the evening meal without requiring high levels of electricity use during the peak periods. Encouraging this sort of load shifting can increase the quality of electricity delivered without an increase in the generation capacity of the system, eliminating the need for diesel backup generators or potentially hazardous and expensive battery banks. 

The purpose of this project is to develop a “GridShare” device that uses smart grid technology to encourage load shifting. Changing the time of use of high power appliances can reduce the severity of brownouts on power-limited mini-grids, potentially increasing the utility of renewable energy mini-grids worldwide.

In Phase I of the P3 project, a prototype GridShare was designed and built to demonstrate the ability for the technology to encourage load-shifting in two ways: by using red and green LED lights to indicate the state of the grid to the user and by preventing residents from using large appliances during brownouts. The objectives of Phase II of the P3 project are to improve upon this original prototype and test the GridShare devices in a village-scale pilot installation in Rukubji, Bhutan. 

Rukubji, a village of approximately 90 households connected to a 40 kW micro hydro system, currently suffers from daily brownouts and serves as an excellent location to implement a pilot installation to evaluate the potential of the GridShare technology to reduce brownouts in village scale renewable energy systems (Figure 2). To perform the pilot installation, 120 GridShare devices were designed, tested and manufactured. In collaboration with the Bhutan Power Corporation and the Department of Energy of Bhutan, 89 devices were installed in June of 2011. These devices will be monitored through at least January of 2012 to determine their effectiveness, reliability and the degree of user satisfaction. If successful on this small scale, GridShare technology has the potential to increase the viability of renewable energy mini-grids in communities worldwide.

Progress Summary:

The GridShare team has been very successful in our work on Phase II. After receiving the Phase II award, we immediately started work on an initial summer field visit to the village of Rukubji in July of 2010. During the visit we held community meetings to introduce the project and demonstrate the prototype, surveyed every household and installed voltage and current loggers to monitor the electric system for the duration of the project. The surveys investigated residents’ current electricity use patterns, issues with brownouts and interest in the GridShare as a solution.  

Findings from this initial visit included over 96% of households reporting that they experienced brownouts once or twice a day, and all but three households stated that they could use their rice cookers at an earlier or later time to reduce the brownout problem. All households agreed to participate in the project. In addition to these findings, through investigation of the electrical system, community feedback and initial testing of the GridShare prototype, the GridShare team identified several design improvements.  

After the initial site visit, the GridShare team redesigned and tested the circuits and enclosures with a series of environmental and functional tests to ensure their ability to operate in the harsh climate of Rukubji and on the extremely variable electric grid with extreme fluctuations in both voltage and frequency. For quality control and to speed the manufacturing process, printed circuit boards (PCB) were assembled by outside companies, while student volunteers completed the final assembling and testing of each PCB in its weather-proof enclosure. After testing each GridShare, all 120 devices, along with 120 circuit breakers, were shipped to Bhutan for the installation in June of 2011. In approximately 10 days, the team installed a total of 89 GridShares on 81 houses and two local businesses. The

GridShares which were shipped but not installed are being stored in Rukubji in case new houses are built or any existing units fail during the project period.  During and after installations, the team talked with members from each household to ensure they understood how the device worked and who to contact if they had questions or problems with the device. All reported problems were resolved while the team was in the village and, as of early August, no further issues have been reported. Many residents expressed their excitement for the project and stated that the LED lights were very helpful in indicating when they can reliably cook without risking spoiled rice.      

Future Activities:

The GridShare team has successfully designed a “GridShare” device that uses smart grid technology to encourage load shifting. In the spring of 2011, the team manufactured and tested 120 GridShares and created bi-lingual education materials to help users learn how to interact with the GridShare and better manage their limited electric system.  Along with their partners in the Bhutan Power Corporation, the team installed over 80 GridShares in the village of Rukubji, Bhutan in June 2011.  The first few weeks have yielded positive results, yet the team plans to monitor the devices for six months to determine their effectiveness, reliability and the degree of user satisfaction. If successful on this small scale, GridShare technology has the potential to increase the viability of renewable energy mini-grids in communities worldwide. 

Journal Articles:

No journal articles submitted with this report: View all 4 publications for this project

Supplemental Keywords:

Micro-hydroelectricity, renewable energy, sustainable economic development, Bhutan, brownouts, mini-grid electric systems

Progress and Final Reports:

Original Abstract

2011 Progress Report

Final Report

P3 Phase I:

Smoothing the Peaks: Smart Outlets to Reduce Brownouts on Micro-hydroelectric Minigrids in Bhutan  | Final Report