Monday, November 20, 2017

How Much Would It Cost to Power Puerto Rico With Solar Energy?

(Clean Air Watch is pleased to present this topical guest post by Kyle Pennell)

When Hurricane Maria slammed into Puerto Rico in late September, the island was decimated. The official death toll is still less than 100 people, but that number will likely continue to rise due to contaminated water and a lack of medical supplies and services.

In addition to the lives lost, Maria caused an estimated $95 billion in damage. Most of the nation’s critical infrastructure was destroyed. Along with the roads, bridges, and dams, the national electric grid was also wiped out. Though it’s been over a month since the hurricane hit, over 60 percent of Puerto Ricans still lack electricity. That means millions of the country’s 3.4 million citizens are without reliable power.

Despite the grim situation, the disaster in Puerto Ricolike Hurricanes Irma and Harvey that preceded italso inspired tremendous generosity. Richard Birt, a Las Vegas Fire & Rescue captain, organized a microgrid for one neighborhood in San Juan. Birt secured funding and donations from Empowered by Light (a nonprofit backed by Leonardo DiCaprio that brings solar power to developing countries), Sunrun (a rooftop solar company), and GivePower (an organization that specializes in solar installation in conflict zones). Sunrun donated the solar panels, while GivePower and Empowered by Light completed the installations.

But fixing Puerto Rico’s energy infrastructure will take more than a few acts of kindness and humanitarian aid. The damage is so serious that merely repairing the existing grid is probably not an option. About 80 percent of transmission lines (the lines that move electricity from power plants to homes and businesses) were destroyed. Ken Buell, director of Emergency Response and Recovery with the US Department of Energy, said, “We really should think in terms of rebuilding at this point.” 

Buell isn’t the only one thinking about how Puerto Rico can emerge from the ravages of Maria with a stronger, smarter grid. Shortly after the hurricane struck, Tesla founder and CEO Elon Musk tweeted about the possibility of rebuilding Puerto Rico with solar power and batteries. Tesla has been making waves in the home solar industry since its announcement last year that it would begin developing solar shingles and a solar battery system, the Powerwall. “The Tesla team has done this for many smaller islands around the world,” Musk wrote, “but there is no scalability limit so it can be done for Puerto Rico too. Such a decision would be in the hands of the Puerto Rico government, PUC (Public Utilities Commission), any commercial stakeholders and, most importantly, the people of Puerto Rico.” Puerto Rico’s governor, Ricardo Rossello, was receptive to the idea, replying “Let’s talk” in a tweet early in October.

Solar would certainly be far more affordable than the current solution, which relies on noisy, polluting gas or diesel generators. According to some estimates, Puerto Rico could be without power for up to a year, and the cost of running these generators is high. Adriana Gonz├ílez, a Sierra Club organizer in Puerto Rico, said that generators are simply too expensive for many people, and that in her neighborhood, “you have one house illuminated, and then total darkness for like a block.”  

More importantly, the generators are a threat to public health. At least four people in Florida died from carbon monoxide poisoning and over a dozen more were injured after resorting to generators when Hurricane Irma tore through the state. Installing solar panelswhich, unlike generators, produce energy silently and cleanlyis an obvious solution.

Rebuilding the energy grid in Puerto Rico to enable more solar energy would also be in line with the country’s longstanding energy goals. Puerto Rico’s own renewable energy standards, approved in 2010, mandate that at least 12 percent of electricity should be produced by renewable energy sources. (In 2020, these standards will increase to 15 percent.) But by June of 2017, Puerto Rico was still producing only 127 megawatts of solar energy and renewable energy accounted for less than 3 percent of the island’s overall energy production. Even repairing the grid wouldn’t allow Puerto Rico to meet its renewable energy quota, since the existing grid can only incorporate an additional 580 megawatts of renewable energy. 

Clearly, now is the time for a change. Solar savings in Puerto Ricoa tropical island with year-round suncould be significantly higher than elsewhere in the U.S. Puerto Rico has traditionally relied on fossil fuels like coal and petroleum to meet its energy needs. But since it has no fossil fuel reserves of its own, it has had to rely on fuel imports, making it one of the most expensive energy markets in American territory. While most homeowners in the contiguous United States pay around $0.12 per kilowatt-hour for electricity, Puerto Ricans are paying closer to $0.20 per kilowatt-hour. Among American states and territories, only Hawaii has higher energy costs.

For an already impoverished island nation, rebuilding a grid with such obvious limits makes no sense, economically or otherwise. But how much would it cost to transition Puerto Rico to solar energy?

Any calculation has to include the existing debt burden of Puerto Rico’s national electric utility, the Puerto Rico Electric Power Authority (PREPA). PREPA had serious financial problems long before Maria leveled the island. The utility is bankrupt and holds at least $9 billion in debt. Unless Congress approves a debt relief package, this debt could prove a significant roadblock to future energy investment.

One way to bring solar power to all of Puerto Rico is to adopt the Tesla model: solar panels (or shingles) on every roof and a Powerwall battery in every home. The cost of installing a standard Powerwall is over $46,000 without incentives. But that estimate assumes a level of energy consumption on par with average Americans. In fact, Puerto Ricans consume about one-third the amount of energy per capita that most Americans do. These homes would therefore need far fewer of Tesla’s solar tiles. For the sake of simplification, we can divide the initial cost estimate by three, leaving a quotient of slightly over $15,300 per home. Since there are about 1.3 million homes in Puerto Rico, the total cost would come to nearly $20 billion.

But a more realistic plan would involve using utility-scale solar installations to meet or slightly exceed Puerto Rico’s current renewable energy standards. If Puerto Rico were to generate 20 percent (about 4,000 gigawatt-hours) of its energy through solar, for instance, it would need to install about 2,650 megawatts’ worth of solar panels.

The amount of land necessary for a solar installation depends on the type of plant constructed. Fixed-tilt utility-scale solar systems (which have no moving parts) require 13 percent less land than one-axis tracking solar systems (which move up-and-down or left-to-right). 

There are no 2,650-megawatt solar power plants; the world’s largest plant, China’s Tengger Solar Park, is only 1,547 megawatts. Puerto Rico would instead have to build a series of smaller plants across the island. About a dozen 250-megawatt plants, for instance, would do the trick. The California Valley Solar Ranch, a plant of this capacity, measures about 8 square kilometers. Another 250-megawatt plant, Nevada’s Silver State South Solar Project, has a land footprint closer to 12 square kilometers. The Agua Caliente Solar Project in Arizona occupied about 7 square kilometers when it was first built (but after expanding the facility to 290 megawatts, it now covers over 9 square kilometers). Assuming a land footprint of 10 square kilometers for each of Puerto Rico’s solar installations, the entire project would require just over 1 percent of the island’s land (which totals about 9,100 square kilometers).

The cost of implementing solar on this scale is also difficult to estimate. Like a home solar installation, the cost required to develop a solar power plant varies depending on the equipment and labor that goes into the project. Some Chinese solar installations have been built for as little as $1.29 per watt. This includes module costs of approximately $0.50 per watt, with all other building costs making up the remainder. But the U.S. Energy Information Administration estimates that the average base cost for a new utility-scale solar installation is about $2.17 per watt. The higher U.S. estimate is likely due to America’s higher soft costs (like labor and permitting) as well as higher module costs (which sit today at $1 per watt, before factoring in incentives). 

Assuming an installation cost of $2.00 per watt, one-fifth of Puerto Rico’s total energy needs could be met for an investment of $5.3 billion. It would cost $26.5 billion to meet the entire island’s electricity generation needs (20 billion kilowatt-hours per year). And meeting its entire residential energy generation with solar roofs would be slightly less expensive: about $20 billion.

Kyle Pennell is the Content Manager at PowerScout ( -- we help homeowners figure out if installing solar is right for them and get competitive bids from multiple installers. Our long-term mission is to accelerate the adoption of solar (and other smart home improvements), which will help mitigate climate change.

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