Puerto Rico 100% renewable in 2050. Reality or fiction?

Definitively, I am not more clever than dozens of researchers from well-known institutions such as the DoE or NREL, or National Laboratories such as Sandia, Pacific Northwest, Lawrence Berkeley, Argonne, and Oak Ridge altogether, plus 116 local advisors from corporations, Public Institutions and Universities in Puerto Rico.

Additionally, they ran a community engagement tour and industry sector roundtables, conducted in partnership with the Puerto Rico Grid Modernization and Recovery Team led by U.S. Secretary of Energy Jennifer Granholm.

The outcome? They have developed the PR100 report, the acronym for the Puerto Rico Grid Resilience and Transitions to 100% Renewable Energy Study., after 2 years of work.

So I fully trust their conclusions.

This report will become the Bible of the Energy Transition in Puerto Rico and the roadmap to unlocking the Energy Trilemma (the currently unsolved dilemma among Energy Security, Energy Sustainability, and Energy Affordability) on the island. I am sure several islands will mirror this exercise and will follow Puerto Rico’s leadership and commitment.

Moving to a 100% renewable system on an island like this would be ideal, as the country is suffering from the volatility of international fuel prices, and most of the current thermal power fleet is not properly maintained and is not flexible and efficient enough.

The PR100 includes an exhaustive theoretical model with 12 cases, based on 3 criteria:

-????????? 3 scenarios based on the varying levels of distributed generation

-????????? 2 sensitivities to address the preservation of agricultural land which is a high priority for many people

-????????? 2 variants with Mid and Stress electric load projections

In a region with forecasted long-term declines in population and real gross national product.

Understanding this report has to be somehow politically correct, I want to highlight and comment on the Top 8 conclusions of their report:

(*All the text below are quotes from the report except those noted as "MY COMMENT" which are my opinions)

1. The price of the electricity will be higher at the end of the Energy Transition

• We found that the utility-incurred costs to transform Puerto Rico’s electric grid to one that is reliable will be significant regardless of the mix of generation technologies. Because the cost variation is more meaningful over time than by scenario, we examined two scenario variations to demonstrate cost changes over time: 1LS (Scenario 1, Less Land, Stress load) and 3LS (Scenario 3, Less Land, Stress load)

MY COMMENT: I told you… Energy Transition brings several benefits, but it is really really expensive, ending in higher tariffs, whether we like it or not. It is pure math.

2. The current energy efficiency goal of 30% by 2040 is shown to be aggressive compared with the results of our bottom-up analysis which show 18% energy efficiency by 2050.

• Currently, very limited resources are available for energy efficiency improvements in Puerto Rico.

MY COMMENT: We have seen in other parts of the globe that electrification and energy efficiency are driven by savings, becoming very slow animals.

3.?Under all scenarios and variations, the amount of rooftop PV capacity and storage capacity deployed in Puerto Rico by 2050 will be significant both in aggregate (2,500 to 6,100 MW) and in the instantaneous power supplied back to the grid during the day.

MY COMMENT: The current 1:1 ratio of Net Metering is artificially driving the rooftop PV installations. This is financially unsustainable so whenever the ratio worsens, the penetration will drop.

4. We observed that the current pace of utility-scale deployment is likely too slow to result in 40% renewable energy by the 2025 statutory deadline and a reliable grid in the near term.

• To achieve 40% renewable energy, the optimal expansion planning results include 2,600–3,500 MW of utility-scale PV capacity, depending on the scenario, along with approximately 700 MW of 4-hour-duration utility-scale batteries, 260–400 MW of long-duration storage, and 170–340 MW of land-based wind.
• Much of the roughly 4 GW of existing fossil-fueled generation remained in the system in this phase.

MY COMMENT: I have some concerns about whether the models include a capacity market or a similar solution for the existing thermal power fleet. It is not sustainable to get paid only by MWh, with fewer orders dispatched but the same costs or even higher to accommodate flexible operation. If one or some operators decide to close plants because they are losing money, the transition model might collapse.

5. The curtailment of utility-scale PV [on top of the generation dedicated to charge batteries] is between 3,5 and 5,5 TWh per year among the 12 scenarios

• Compared to utility-scale PV generation, it means between 30% to 90% of the electricity production, depending on the scenario (grey area VS orange area):

MY COMMENT: Investors will be disincentivized as this has a huge impact on their business cases. This is a chicken-and-egg situation that delays Energy Transition.

6. The lower-voltage (38-kV) transmission network components are insufficient to handle the projected system transitions.

MY COMMENT: An abundant rooftop PV deployment with net metering requires a robust and meshed grid. This is costly and it takes time to deliver. But it is probably one of the first investments to do.

7. Results indicate that to mitigate large frequency deviations and contribute to black start and grid recovery, 300 to 800 MW of battery energy storage with GFM functionality and the ability to set up fast frequency response (1% droop) will be key for the short term.

MY COMMENT: Once Thermal Power Plants are out of the system, the whole grid frequency will rely on expensive inverters and abundant storage. The plan does not include another solution to interconnect Puerto Rico’s electric system with the Dominican Republic’s one by submarine cable. That would bring additional benefits, would reduce the total cost of ownership, and would allow an electricity import/export business to reinforce the feasibility of the energy transition.

8.?Very low-income households (earning $15K/year or less) were particularly vulnerable to large retail rate increases, especially if they were more likely to be nonadopters of rooftop PV, resulting in energy justice implications.

MY COMMENT: The Energy Trilemma really has a fourth element which is the social impact on citizens. In European countries where renewable penetration is higher, we can see that energy poverty is rising, limiting access to electricity (e.g. heat during cold winters) to millions of people. The Energy Transition must be fair and just not to leave anyone behind. And that takes time and more money.

If so many experts say Puerto Rico will achieve 100% of renewables in 2050, I do not question it. However, reading their own conclusions, I am confused if they really say so or not.

[ACCESS THE FULL REPORT AT https://www.nrel.gov/docs/fy24osti/88615.pdf ]