When considering the future energy mix of Puerto Rico, worsening hurricane seasons and high levels of poverty in the territory are top of mind for energy experts.

Distributed generation is critical to boosting energy resilience on the island, participants noted yesterday at the Black Start 2019 conference in Puerto Rico, reflecting on lessons learned from Hurricane Maria in 2017.

Energy, policy and regulatory experts discussed a transition to cleaner, distributed generation as a cost-effective solution to harden the U.S. territory's grid. Besides the high price tag of shipping fossil fuels to generate electricity, the island's centralized system remains vulnerable to extreme weather events.

The San Juan-based conference came amid anticipation of a bipartisan bill that would mandate 100% renewable energy in Puerto Rico by 2050. The bill, PS 1121, has already passed the Puerto Rico House and Senate and a final version needs to be approved by the House in conference committee before being sent to the governor's desk.

Legislative expectations

Puerto Rico Sens. Larry Seilhamer and Eduardo Bhatia, who both spoke at Black Start, introduced the bill in response to decisions to privatize the Puerto Rico Electric Power Authority (PREPA).

"I firmly believe it's going to pass," Seilhamer told Black Start attendees.

The president of the Puerto Rico House, Carlos Johnny Méndez, told Seilhamer "he expects the bill to be approved by the House next Monday," according to Seilhamer. The House left session March 18 without approving the unified version of the bipartisan bill.

The proposed renewable energy mandate has interim goals to accelerate deployment: 40% by 2025 and 60% renewable energy by 2040. SP 1121 exempts energy storage systems from sales tax. On stage at Black Start, Seilhamer called for having no tax on clean energy resources.

The renewable energy goal will serve to shift long-term resource planning, Jorge Camacho, a former regulatory staffer working with the National Institute of Standards and Technology (NIST), told Utility Dive.

The deployment of renewable energy will be critical to a successful transition, experts said at Black Start.

The shift away from centralized generation will help protect the grid against future weather events like Hurricane Maria, Camacho said. Microgrids "definitely will add resilience to the load pockets on the island."

The role of distributed generation

The National Infrastructure Advisory Council issued in December a report on power outages, calling for community enclaves powered by microgrids throughout the United States. The need for enclaves is particularly strong in Puerto Rico, as transmission towers and lines crossing the island's central mountains and forests are vulnerable to extreme weather, according to Ruth Santiago, a lawyer who spoke at Black Start.

However, using distributed generation would be a preferred solution for Puerto Rico because it's cheaper, she said, noting a low-cost solar PV system prototype being developed to suit low-income families.

"The cost of customer-owned generation is significantly lower than the total rate under the preferred plans" of PREPA, Santiago said at the conference, based on the conclusions in PREPA's integrated resource plan (IRP), prepared by Siemens.

Santiago criticized the IRP for only including customer alternatives as 10% of the generation mix by 2038, although the Siemens analysis noted that it's the cheapest option.

While the PREPA IRP included record amounts of solar and battery storage coming online in the next 20 years, the plan still involved fossil-fuel burning plants and infrastructure, such as three liquefied natural gas import terminals.

"Right now there are some [Puerto Rico] communities already that ... have disconnected from the grid and they're taking charge of their own," Camacho said. Enclaves disconnected from the grid are successful because of the low energy needs of the community, he added.

Some groups are working to make more microgrids in Puerto Rico a reality.

The Environmental Defense Fund (EDF) unveiled on Thursday a plan to deploy sustainable and scalable low-carbon microgrids in rural parts of the territory. The idea is to deliver solar energy by using battery storage, to deploy when it's most needed. The microgrids "can connect to the larger grid and also disconnect during blackouts to keep electricity flowing to hospitals, traffic lights, schools and other critical services," according to a statement from EDF.

Specific power and energy capacities were not immediately available.

The Puerto Rico initiative will be financed through public grants, philanthropic funds and impact-focused private capital, Fred Krupp, EDF's president, said in a statement.