The Microgrid Laboratory at UPRM's Sustainable Energy Center

by Kristy Dwello, Kimberly Colgan, Gabriel Chan

We spent Friday morning at the Microgrid Laboratory in the Sustainable Energy Center at the University of Puerto Rico - Mayagüez (UPRM). Juan Felipe Patarroyo Montenegro, UPRM  PhD student in electrical engineering, and Marcel Castro-Sitiriche, UPRM electrical engineering professor,  gave our group presentations on microgrids and energy systems in Puerto Rico. According to the Department of Energy, a microgrid is ‘‘a group of interconnected loads and distributed energy resources within clearly defined electrical boundaries that acts as a single controllable entity with respect to the grid.” As described in more detail in a previous blog post, the energy system in Puerto Rico is currently characterized by fossil fuel power generation systems and a centralized grid. Microgrids would provide an alternative to this system with more decentralized control and resilience.

As a relatively high consumer of electricity in the Caribbean with an electric grid that has painfully been revealed as more vulnerable to disruptions than previously considered , Puerto Rico could benefit from the implementation of microgrids. With a focus on solar energy, microgrids could increase the resilience of Puerto Rico’s grid by allowing communities to operate their own disconnected energy systems and function independently in the case of system failure. This could especially be beneficial in light of the extended outages after large-scale system disruptions, such as those that followed Hurricane Maria. The use of solar energy over diesel fuel or natural gas in a microgrid could also provide environmental benefits to local communities, particularly where a renewable-powered microgrid replaces a diesel-powered alternative.

Juan Felipe Patarroyo Montenegro is a PhD student in Electrical Engineering from Columbia. From him, we learned about what the UPRM Microgrid Labdoes, who they partner with, and where they get their funding. The Microgrid Laboratory uses simulations of weather and power generation in conjunction with real electrical system hardware to test the productivity of microgrid systems and how they perform under varying conditions. Collaborating with the University of Alaska, University of Southern Florida, the Department of Energy, Polytechnic University of Catalonia, Aalborg University, and more, the lab’s work is truly global.  The UPRM Microgrid Lab is also the first and only research group focusing on microgrids in Puerto Rico,  which is significant given the policy attention microgrids have received following Maria. A grant from the National Science Foundation is providing funding for more equipment and computing power, that will allow the lab to simulate all of Puerto Rico in their future research.

We learned that there is a lot of variability in solar power generation that affects possible microgrid performance. Irradiance, temperature, and cloud cover all impact solar energy output, and with a smaller number of generation sources, microgrids must account for this variability with sufficient energy storage in order to provide reliable service. To study these issues with real performance inputs and smart grid infrastructure, the Microgrid Laboratory hopes to connect the Lab’s microgrid simulation equipment and metering systems to the OASIS solar house on campus.

OASIS Solar House, UPRM

OASIS Solar House, UPRM

University students, like most consumers, are often unaware of their energy footprint. Because of this, the Sustainable Energy Center, the parent organization of the Microgrid Lab, plans to incorporate education of students and the greater community into their work. Juan believes that “you cannot be selfish with your research”, and because of this hopes to also use the Lab as a theater to show different energy scenarios to the public and teach people how to manage energy issues.

After our conversation with Juan, we were joined by Marcel Castro-Sitiriche, a professor of Electrical Engineering at the University of Puerto Rico - Mayagüez in the Electrical and Computer Engineering Department. Marcel shared with us the context and history of the greater energy system in Puerto Rico. He highlighted the Integrated Resource Plan (IRP), currently in development, which establishes a pathway for the development of an electric power system and the improvement of the efficiency, reliability, affordability, and transparency of the system. The first IRP was filed by Puerto Rico Energy Power Authority (PREPA)  in 2015, and was rejected by the Puerto Rico Energy Commission because it did not include renewables, demand-response planning, nor energy efficiency in a meaningful capacity. The most recent draft of Puerto Rico’s IRP includes solar, but most is utility-scale solar installations, while comparatively, much less is generated by customer-owned, distributed solar sources.  

Kristy and Kimberly in the Microgrid Laboratory, UPRM

Kristy and Kimberly in the Microgrid Laboratory, UPRM

Marcel described the complex web of players in the IRP process that are creating potential conflicts of interest, particularly in envisioning a desired infrastructure scale (e.g more centralized or more decentralized) and mix of energy sources in the future Puerto Rican electricity grid.  Siemens led the preparation of the first IRP in 2015, which prioritized natural gas over renewables. Their most recent IRP proposes solar generation, but at the utility scale, and very little customer-owned generation. There is still a lot of work to be done to move the IRP into implementation. From our discussions in Puerto Rico, we were left with a lot of questions about how stakeholders are engaging in the IRP process and how PREPA’s plans for managing the energy system are accounting for the uncertainty in their privatization requirements. As we ended our morning in the UPRM Electrical Engineering Department, we felt that the tension between two visions of Puerto Rico’s energy system after Maria is just as strong as ever: will the system move to one that is more bottom-up, small-scale, and distributed with locally controlled microgrids that support system resilience? Or will the system be driven by top-down processes that drive outside capital toward large-scale, more easily financed, and perhaps more affordable energy? Can Puerto Rico’s communities afford to do the difficult work of community organization that  takes time, effort, and emotional labor before the next hurricane hits? Or is the more responsive strategy to build back an electricity system that connects as many people as quickly as possible and then work on energy transition only once the grid is hardened?