Microgrids Power Rwandan Villages From the Bottom Up
- May 31, 2018
- 761 views
According to Daniel Zimmerle, Senior Research Associate in the Energy Institute at Colorado State University (CSU), about 1.2 billion people worldwide have no access to electricity, and about half that number are faced with limited or unreliable access. About half of people without electricity live in sub-Saharan Africa; in some countries fewer than half of citizens have access to electricity. That’s why Zimmerle and others have created an initiative to build microgrids in the thousands of communities needing access there.
The microgrid challenge is enormous, and has required an alliance with a local microgrid company, MeshPower, just to install 10s of community microgrids per year. But, this project is merely one component of the real goal Zimmerle’s team is trying to accomplish: spurring economic development.
A Vicious Cycle
The microgrid project began years ago, when a CSU team was working on another project to distribute cookstoves that could improve human and environmental health, and eliminate the toxins associated with cooking over an open fire. The team noticed that residents had to walk miles and pay money to charge the cellular phones they needed to track agricultural information, or were utilizing dirty and dangerous kerosene wick lights to provide lighting for their children’s studies.
Around the same time another CSU group was working on agricultural development in the area, and kept running into power problems. “Without power they couldn’t run equipment, such as refrigeration units,” explained Zimmerle, “which is not just an agricultural and energy problem, but also a social one. The lack of electricity impedes economic growth, which impedes access to electricity. It’s a vicious cycle. These issues are all a part of the same thing; it’s a cross-disciplinary problem requiring a multifaceted solution1.”
The Benefits of PV
CSU’s alliance with MeshPower is meant to address at least parts of this problem. Zimmerle noted, “MeshPower was doing the same thing we were doing — installing microgrids — so we merged efforts and formed a company-university partnership. CSU now owns part of the company, and part of the donations we get for this project goes to them.”
The combined organization focuses on photovoltaic (PV) systems because, said Zimmerle, “PV isn’t location-specific over a regional size area. In a large area, you might have some spots that are better for hydro generation, and some that are better for wind, but generally solar is going to be the same throughout a bigger area. Essentially we can install it here or 20 or 100 miles from here and get the same results. PV is also price competitive, and once it’s installed it runs on its own. For those reasons, most microgrid development is PV-heavy.”
A Hybrid Model
The microgrids support both residential and commercial activity, and are targeted to typical uses. People living in the villages where the microgrids are being installed are clear about their needs. First, they want to eliminate the necessity of walking several miles to and paying high rates at a location that has electricity, just to charge their mobile phones. “We want to help them stop exporting cash from their village,” commented Zimmerle. The amount of power needed within a household to run a fan, operate a TV, charge a mobile phone, and use a light is close to the amount of power U.S. residents would typically use just to charge their computer.
A second priority is creating sustainable exports from the villages. The exports include subsistence products such as produce, milk, and eggs, or cash crops like fruit or grain. Zimmerle described the challenges associated with this seemingly simple goal: “Let’s say I’m a subsistence farmer. The last thing I want to do is plant one crop, because if it goes bad I starve. Here in the U.S. we take things like crop insurance for granted, but in Rwanda it’s something that needs to be addressed. To move from subsistence to export, which would bring in more revenue, these farmers must learn things like growing cash crops, insuring against crop failure, and maintaining consistent quality levels.”
The amount of power required for agricultural activities, or other commercial requirements — such as someone who cuts hair — is higher. The MeshPower microgrid system works on a hybrid model, with 220 volt AC power to business areas, and lower-cost 48 volt DC power distribution to homes.
Continued efforts to create more microgrids prioritize villages with clinics or schools. Zimmerle noted, “It’s hard to know how many we will do. We’re moving into being able to do 100 at a time.”
Zimmerle observed that the power development process in Rwanda is very different from places like the U.S. in that it’s a “bottom up” operation. Rather than energy distribution coming from an external location — such as a power company — and customers slowly contributing their own power to the grid, in Rwanda and other places distributed power sources may be a better foundation. Zimmerle remarked, “At some point it will be tied to a national grid — or maybe not. Conceptually every village can stand on its own and doesn’t need to be connected to the grid to function. That prevents the problem we have here; when everyone is connected, if the grid goes down, everything goes down.”
The key to making microgrids work in this way is inexpensive batteries. Zimmerle said, “If we get inexpensive, long-lived batteries, they’re the catalyst for affordable power in the developing world.” Zimmerle believes the ideal scenario is a series of microgrids tied together into clusters of working power systems.
As he and his team work toward making power more accessible in developing countries, and helping the residents of those countries become more self-sufficient, Zimmerle’s ultimate goal is to have them not need assistance any longer. He said, “We want to help them get their efforts off the ground and give them the tools to do so. But we hope to see those efforts become self-sustaining. When they no longer need us — that’s when we’re truly successful.”
1Daniel Zimmerle (Senior Research Associate in the Energy Institute at Colorado State University), in phone interview with the author, May 2018.
Photo credit: Daniel Zimmerle