SERC Develops Mini-grid Interconnection Guidebook

SERC is collaborating with Chris Greacen of Palang Thai to develop a guidebook on the interconnection of mini-grids to national or regional electrical grids. Titled A Guidebook on Grid Interconnection and Islanded Operation of Mini-Grid Power Systems Up to 200 kW, the document addresses both technical and policy aspects of interconnection and is intended for energy policymakers, mini-grid operators, utility administrators and engineers, and community leaders. Worldwide, more than 50 million households get their electricity from renewable energy mini-grids powered by small hydroelectric generators, wind turbines, or solar photovoltaic arrays. These systems provide clean, reliable electricity to rural locations not yet served by national or regional electric grids. They may be developed by traditional utilities or, more commonly, by private-sector developers.

When a national grid reaches areas previously served by isolated mini-grids, operators are faced with several challenges. Will customers served by the mini-grid be connected to the main grid? If so, what happens to the mini-grid’s generator, power lines, and other equipment? Will these assets be abandoned, or will the generator become another power plant selling electricity to the grid? If the mini-grid system remains independent from the grid, how can the operator keep electricity prices competitive?

If there is no policy in place to address these issues, mini-grid developers may be reluctant to invest in new projects and may use substandard wiring and undersized equipment to reduce costs, knowing that their investment could be made worthless at any time if the national grid arrives. These problems plagued mini-grid systems in Cambodia until the government developed a policy to allow mini-grid operators to become small power distributors (SPDs) and resell electricity from the grid. Since these regulations were instituted, over 100 isolated mini-grids have been converted to SPDs. Other developing countries with interconnection policies include Thailand and Tanzania.

Renewable energy mini-grids, like this micro-hydroelectric system in Rukubji, Bhutan, provide electricity for millions of households worldwide.

Renewable energy mini-grids, like this micro-hydroelectric system in Rukubji, Bhutan, provide electricity for millions of households worldwide.

The interconnection guide discusses technical topics, including voltage and frequency control methods and protective relays, as well as mini-grid policies from developed and developing countries around the world. A draft version of the guidebook is currently being reviewed by outside experts, and final publication is tentatively slated for early February 2013. The guidebook is being developed for Lawrence Berkeley National Laboratories under the auspices of the US Department of Energy’s Global Lighting and Energy Access Partnership (Global LEAP). This program is associated with the Clean Energy Ministerial, a global forum promoting clean energy policies and programs.

A Message from the Director

I am honored to write my first newsletter column as Director of the Schatz Energy Research Center. The faculty, staff, and students who work at SERC are a talented and dedicated group of people, and it is a privilege to work with such a fantastic team.

As I start in this new role, I am conscious of the large shoes I am attempting to fill. Peter Lehman has directed SERC boldly and effectively since it was founded in 1989. I feel fortunate to have the opportunity to collaborate closely with Peter over the years to come as he continues to play a leading role in his position as Founding Director.

Under the leadership of Peter and long time Co-Director Charles Chamberlin, SERC has built a reputation for taking on innovative and challenging renewable energy and energy efficiency projects that make a difference for the environment and society, carefully measuring and analyzing energy system performance, and building things that work. It was, in fact, these characteristics that attracted me to SERC, first as an Environmental Resources Engineering (ERE) master’s student back in 1992 and later—after completing a PhD in Energy and Resources at UC Berkeley—as a faculty member in the ERE department in 2005. These traits are now deeply embedded into the culture of who we are at SERC, and we will, of course, strive to build on them.

Since becoming a Co-Director at SERC in 2007, I have worked with Peter, Charles, and the broader team to develop three key themes at the Center. First, we have worked to increase student involvement in SERC projects. Second, we have taken on interdisciplinary projects that combine technical rigor with policy and social science analysis. And third, we have diversified our portfolio of projects; for example, we now have a robust set of international efforts that complement our local, state, and nationally oriented projects. These will continue to be high priority themes going forward.

The lead story in this issue exemplifies the marriage between SERC’s longstanding core capabilities and the emerging themes we have been working to add. The GridShare project involves the application of smart grid concepts to improve the quality of electrical service from a village scale renewable energy mini-grid in Bhutan. Successful implementation involved collaboration with international partners and an interdisciplinary approach that spanned technical, socio-economic, and educational activities. The project was also a student-led effort that provided significant opportunities for learning and professional development for both graduate and undergraduate students.

Closer to home, in this issue we also report on an analysis of infrastructure needs for plug-in electric vehicle infrastructure for Humboldt County; the release of RePowering Humboldt, a strategic plan for scaling up renewable energy use over the next two decades here in Humboldt County; and progress on the HSU hydrogen fueling station upgrade. It is exciting to be involved in this diverse and meaningful set of projects. I look forward to many more in the years to come.

GridShare Success in Bhutan

We’re excited to report on the successful installation of GridShares on a small microhydro mini-grid in Bhutan. In our Summer 2011 newsletter, we wrote about our upcoming fieldwork in the Bhutanese village of Rukubji, and we can now share our results and the feedback we’ve received from the village. The GridShare is a demand-side management device designed by our group of HSU students and advisors and is intended to reduce the occurrence of brownouts on power-limited mini-grids. The GridShare device encourages 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, like rice cookers and water boilers, during brownouts.  After winning a grant to support the project through the EPA’s People, Prosperity and the Planet (P3) Student Design Contest in 2010, we improved upon our original prototype and tested the GridShare devices in a village-scale pilot installation in Rukubji, Bhutan.

View of Rukubji, Bhutan           A Bhutan Power Corporation technician installs a GridShare           Red and green indicator lights and how the system works signage
Left to right: The main village of Rukubji is located in the center of Bhutan in Himalayan Asia. BPC electrician Sangay Phuentsho installs a GridShare circuit near the electricity meter on the outside of a home near Rukubji, while the red and green indicator lights are installed inside the house near the cooking appliances.

Rukubji, a village of approximately 90 households connected to a 40 kW-rated microhydro system, suffered from daily brownouts and served as an excellent location to evaluate the potential of the GridShare technology to reduce brownouts in village scale renewable energy systems. To perform the pilot installation, our team, with the help of many volunteers, designed, tested and manufactured 120 GridShare devices here at SERC. In collaboration with the Bhutan Power Corporation and the Department of Energy of Bhutan, we installed 90 devices in Rukubji and the surrounding villages of Sangdo, Tsenpokto and Bumiloo in June of 2011.

We assessed the GridShare installation with three main methods: electrical data logging, household surveys and community meetings. We have used HOBO data loggers to continuously monitor the current and voltage of the system since June of 2010, which provides us a year of data before and after the GridShare installation. 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. Community meetings before and after the installation offered opportunities to discuss the GridShare and receive system feedback.

We were thrilled when the community of Rukubji decided by consensus to keep the GridShares installed and the Bhutan Power Corporation agreed to continue to support the effort. Though several improvements to the design and implementation strategy would be useful 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.

To learn more about the GridShare project in Bhutan visit www.schatzlab.org/projects/developingworld/gridshare.html.

Installing data loggers           Meeting with community members           Community meeting where decision was made to keep GridShare installations
Left to right: The three main methods of evaluation of the GridShare project included electrical data logging, household surveys and community meetings.

HSU Students Install GridShare Devices in Bhutan

Gridshare Team in Bhutan

Chhimi Dorji (left), Nathan Chase, and Meg Harper present GridShare education and outreach to Rukubji schoolchildren. Photo credit Arne Jacobson.

For over two years, a dedicated group of HSU students and advisors has been working on the design of a “GridShare” device intended to reduce the occurrence of brownouts on power-limited mini-electric grids. Last year, after winning a grant through the EPA’s People, Prosperity and the Planet (P3) Student Design Contest, three of us traveled to Bhutan to assess the village of Rukubji as a site to perform a pilot installation of our GridShares.

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A Smart Grid Solution to Prevent Brownouts in Bhutan

P3 Gridshare Awardees

The Phase I project team displays the Phase II funding award. l to r Kyle Palmer, James Apple, Meg Harper, Chhimi Dorji, Jenny Tracy, Joey Hiller, faculty advisor Dr. Arne Jacobson, James Robinson, and Nathan Chase.

Students from SERC and the Renewable Energy Student Union (RESU) won a $75,000 EPA grant to implement a Smart Grid device to reduce brownouts on village-scale electrical grids in developing countries. We developed the device, known as GridShare, with support from the EPA’s People, Prosperity, and the Planet (P3) program. In April, we demonstrated GridShare technology at the National Sustainable Design Expo in Washington, D.C. and we were among fourteen teams to receive P3 Phase Two funding. During the next year, we will travel to Bhutan to implement GridShare technology in the remote village of Rukubji.

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