Grantee Research Project Results
Final Report: Smoothing the Peaks: GridShare Smart Grid Technology to Reduce Brownouts on Micro-hydroelectric Mini-grids in Bhutan
EPA Grant Number: SU834749Title: 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 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 Awards , P3 Challenge Area - Air Quality , 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 mini-grids 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 was 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.
Summary/Accomplishments (Outputs/Outcomes):
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. In Phase II of the P3 project the team improved upon this original prototype and tested the GridShare devices in a village-scale pilot installation in Rukubji, Bhutan.
Rukubji, a village of approximately 90 households connected to a 40 kW microhydro system, suffered from daily brownouts and served 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, 90 devices were installed in June of 2011.
Figure 2. The main village of Rukubji is located in the center of Bhutan in Himalayan Asia (L). BPC electrician, Sangay Phuentsho, installs a GridShare on a home near Rukubji (R).
Household surveys were conducted before the installation and again in January of 2012 to assess the effectiveness and reliability of the GridShares and the degree of user satisfaction. Additionally, the voltage and current of the microhydro system has been continuously datalogged since June of 2010.
These comparative data suggest that the GridShares have effectively reduced the depth and duration of brownouts. As pictured in Figure 3, the occurrence of severe brownouts, or times where the voltage dropped below 190 V for more than 10 minutes, were reduced by over 90% on all three phases of the grid. This reduction in brownouts resulted in residents being able to more reliably use their electricity to cook their rice and light their homes.
Figure 3. The percent of days with a severe brownout before and after the GridShare installation on all three phases of the electric grid (B, R, Y). Data suggests there was a reduction of over 90% in severe brownouts after the GridShare installation. Note that this graph uses 129 days of data between July 22nd and June 9th of each year. Data was filtered to ensure data in each year offered comparable generation profiles and did not include intentional blackouts or days of missing data.
The community of Rukubji decided by consensus to keep the GridShares installed (Figure 4), and the Bhutan Power Corporation continues to support the effort. Though several improvements to the design and implementation strategy are necessary before performing additional installations, this pilot project provides evidence that user-interactive demand-side management strategies, such as the GridShare, are effective at reducing brownouts on mini-grids.
Figure 4. The three main methods of evaluation of the GridShare project included electrical data logging, household surveys and community meetings. On the right is the final community meeting when the community decided by consensus to keep the GridShares installed.
Conclusions:
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 90 GridShares in the village of Rukubji, Bhutan in June 2011. In January of 2012, residents reported being able to consistently cook their rice, and said they are appreciative of the GridShare indicator lights that tell them when adequate power is available. Electrical data collected before and after the GridShare installation confirms that the occurrence of severe brownouts has been significantly reduced. As the community and the BPC were pleased with the installation, the GridShares were left installed and ownership of the installation was transferred to the BPC. Both the BPC and the HSU student group plan to continue to monitor the installation, refine the design of the GridShare and investigate other villages for potential installations of GridShares or similar load management devices.
Journal Articles on this Report : 1 Displayed | Download in RIS Format
| Other project views: | All 4 publications | 1 publications in selected types | All 1 journal articles |
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Quetchenbach T, Harper M, Ribinson IV J, Hervin K, Chase N, Dorji C, Jacobson A. The Grid Share Solution:a smart grid approach to improve service provision on a renewable energy mini-grid in Bhutan. Environmental Research Letters 2013;8(014018). |
SU834749 (2011) SU834749 (Final) |
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Supplemental Keywords:
Micro-hydroelectricity, renewable energy, sustainable economic development, Bhutan, brownouts, mini-grid electric systems, South AsiaRelevant Websites:
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Progress and Final Reports:
Original AbstractP3 Phase I:
Smoothing the Peaks: Smart Outlets to Reduce Brownouts on Micro-hydroelectric Minigrids in Bhutan | Final ReportThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.