Larry Greenemeier (Scientific American) focuses on the dilemma Puerto Rico faces regarding its power grids and energy sources. Here are excerpts:
[. . .] The consensus among the U.S. Federal Emergency Management Agency (FEMA), the U.S. Army Corps of Engineers and others involved in the current restoration project is that Puerto Rico is—and has been for a long time—in desperate need of a power grid makeover. Last Wednesday, during a press conference, Ricardo Ramos, executive director of the Puerto Rico Electric Power Authority (PREPA), indicated the utility has created a “transformation plan” to improve service.
[. . .] A microgrid is a local, self-sufficient network of generators, storage devices (typically batteries) and equipment that routes electricity to homes, businesses and other structures that require service. A key benefit of such a setup is that it can operate as part of the main grid or function autonomously. These grids can be powered by diesel-burning generators or a combination of fossil fuels and renewable energy sources such as solar and/or wind.
Distributing the load in this way can alleviate reliance on one main system whose failure could cut power to the entire island. Puerto Rico needs a mix of microgrids disbursed throughout the island to provide electricity in a cost-effective way, says José Antonio Santiváñez, a professor of industrial management engineering at Puerto Rico’s University of Turabo. “Another reason microgrids are a good option for Puerto Rico is that there are hard-to-reach places on the island where [PREPA] said it would never be able to deliver power.” Those residents live off the main grid and already rely mostly on portable generators for electricity. [. . .]
In addition to better distribution of power plants throughout the island, increased use of underground cabling could enable the power company to deliver electricity to customers without worrying about poles and lines downed by hurricane gales. That approach has been effective in areas of Puerto Rico’s capital, San Juan—although the cables could be vulnerable to damage from flooding. The limitations on underground cable include high costs—10 times greater than aboveground lines and poles—and the island’s mountainous terrain. Underground power cables also require more time and money to manufacture than do overhead wires, Hyland says. And, because they are out of sight, it is difficult to know when they have been damaged, he adds. Still, Hyland acknowledges it makes sense to consider subterranean lines in specific parts of the island for the future.
Another approach would be to supplement more of the grid’s diesel oil generators with power from solar and wind farms, although such power sources are too intermittent to replace a fossil fuel grid, Santiváñez says. Renewable energy sources such as solar panels would be good for one house or a group of homes—if they could afford it—but not for the entire island, he adds. “I have a suspicion that those solar panels in particular would be gone with the wind in the event of another category 5 storm,” he says.
[. . .] None of those upgrades will happen anytime soon, however, because FEMA is not allowed to fund them. The 1988 Stafford Disaster Relief and Emergency Assistance Act authorizes government agencies only to restore utility service to its predisaster condition. Additionally, PREPA has no money to pay for upgrades. “The U.S. Army Corps is working to reestablish the grid to U.S. code standards,” FEMA Administrator Brock Long testified at the October 31 Senate committee hearing. “Typically, we have to restore to a predisaster condition, but obviously that is not optimal and not the way I would ever recommend [Puerto Rico] to go. We do not want to be back in this situation again.” [. . .]
PREPA’s bankruptcy in May further complicates Puerto Rico’s efforts to improve grid resilience. The government-owned power authority is responsible for about $9 billion of the island’s $73-billion debt. Puerto Rico formed PREPA in 1941 to be the sole provider of electricity for the island’s then 1.5 million customers. The company’s power plants are, on average, currently more than 40 years old, Long testified, adding, “worldwide, the average age of power plants is 18 years.”
[Solar panel debris is seen scattered in a solar panel field in the aftermath of Hurricane Maria in Humacao, Puerto Rico on October 2, 2017. Credit: Ricardo Arduengo, Getty Images.]