By: Jussi Heikkinen

The Biden administration and Puerto Rico have joined together to launch an ambitious, collective effort to accelerate the growth of renewable energy resources and strengthen the island’s grid – promising 2022 will be “a year of action” in the transition to 100% clean energy over the next three decades.

The partnership involves three U.S. federal agencies – the Department of Energy, the Departments of Homeland Security and Housing and Urban Development to partner with the government of Puerto Rico. The group will complete a two-year study of how the island can reach 100% renewables by 2050, and meet a variety of interim targets along the way. The study, “Puerto Rico Grid Resilience and Transitions to 100% Renewable Energy” (PR100), is expected to be complete in December 2023. The plan addresses a rapid addition of renewables, mainly solar, as well as battery storage advancements.

Last year, I outlined Puerto Rico’s optimal path to decarbonization in an effort to find the optimum way to reach net zero targets, serve the load without black-outs, and provide the lowest cost for the rate payers.

The pace of adding renewables in the new Puerto Rico national plan correlates closely with Wartsila’s former outline – so does the quantity of their proposed battery storage. To ensure efficient utilization of the rapidly growing fleet of renewables, the thermal fleet needs to be modified as well. The key in the path is to make the system flexible enough to enable the addition of large amounts of variable renewables.

A crucial element in getting rid of large quantities of carbon emissions is retiring of the old high-emitting, inflexible coal power plants by 2028. Adding more solar and wind power plants, and battery storage, is the way to go. But in order to do this while maintaining security of supply, the system must have constantly adequate firm power capacity. Firm capacity means 1) available at all times, and 2) can operate as long as necessary. This capacity needs to be highly efficient and flexible – it will need to start and stop hundreds of times every year to enable efficient utilization of renewable energy. As the national plan is to close down thermal plants, the Wärtsilä study shows an obvious risk for rapidly increasing curtailment of solar power, repeated security of supply issues, and even black-outs.

To stay on the optimal decarbonization path and to avoid major curtailment of solar, 450 MW of new flexible gas power plants need to be installed by 2023, followed by another 350 MW in 2028. These plants do not run continuously, but they maintain security of supply, mitigate major overbuild of solar and battery storage, and in turn, save big money. They also enable retirement all of the older thermal power plants latest by 2038, according to plan.

Later on, when the island is ready, the flexible plants will be converted to use green-hydrogen based fuels like hydrogen, ammonia, methanol or methane. This will serve as the final step of the decarbonization in Puerto Rico.

To read the press release on the development in Puerto Rico, visit here.