warm thoughts


Written on: April 5, 2023

When other businesses went dark, this tourist destination kept its lights on during Hurricane Fiona.

From the Propane Education & Research Council

In 2017, Hurricane Maria ravaged Puerto Rico’s electrical grid, requiring island residents to go without power for more than 100 days in what was the largest and longest blackout in U.S. history.

Today, Puerto Rico’s electrical infrastructure remains patchy, having never fully recovered from the devastation of the Category 5 hurricane. Blackouts and brownouts are common even in mild weather, which is why many property owners are seeking secondary power sources to minimize disruptions.

“An outdated grid infrastructure and inconsistencies with power production have been a hot topic of discussion for a long time, particularly when you look at industrial manufacturing facilities in Puerto Rico but also resorts where livelihoods depend on attracting and keeping clientele,” says Jessie Howell, business development manager at 2G Energy.

The St. Augustine, Florida–based company has a regional office in Puerto Rico, where it’s installing combined heat and power (CHP) systems for businesses that no longer want to depend on an unreliable grid. CHP systems differ from backup generators in that they recover waste heat from the production of electricity and put it to use for a building’s hot water and space heating. CHP can be used either as robust backup power or a facility’s primary power source.

2G Energy’s most recent project is an installation at Rincon Beach Resort in Anasco, on the island’s west coast. Here at this secluded resort, a propane CHP system can operate independent of the grid to meet the heat and power demand of the property’s 112 rooms and 24 condos, as it proved in September 2022. That’s when Hurricane Fiona made landfall, causing widespread flash flooding. The island’s fragile electrical infrastructure — still recovering from Hurricane Maria five years prior — suffered significant damage. Nearly 850,000 power company customers — that’s more than half of the island’s businesses and households — were without electricity. Throughout it all, Rincon Beach Resort was able to keep its lights on.

“The 2G propane CHP system allowed us to continue operations through the storm while the majority of facilities struggled to remain online,” says Eduardo Somoza, the resort’s owner.

Determining CHP size and fuel type

Architects and specifiers should work closely with CHP vendors to determine the capacity to meet the critical loads of the facility. In the resort’s case, 2G specified a 240 kW package unit, which comprises a prime mover, generator, control panel, and heat exchanger in a 30-foot container. The system is tied to the grid but can operate on “island mode,” meaning independently of the grid, during blackout emergencies. Howell says the unit was operating at 130 kw during a recent visit “and it was meeting the entire needs of the resort. So, it has additional capacity available.”

The unit has the option to export excess energy to the grid, plus 367 kW of thermal capacity to supply the resort’s hot water.

Most CHP systems operate on natural gas or propane. While liquid natural gas (LNG) is available on the island, Howell says it would require specialized equipment to gasify LNG, “so before you know it, you have $160,000 to $200,000 worth of additional equipment for natural gas.” That’s why resort operators opted for propane. Propane is stored on site as a liquid. It turns into gas when the tank’s pressure is lowered to fuel the CHP’s engine.

CHP vs. backup generators

Backup power generators are prevalent in Puerto Rico — as they are stateside — but they’re not the best option for property owners desiring a cleaner energy source. Standby generators typically run on diesel, which produces significantly more NOx and particulate matter emissions than propane engines. Diesel has a limited shelf life in storage, requiring the use of additives to prevent the fuel from breaking down. In contrast, propane can last decades in a storage cylinder.

“Lots of places can maintain operation on diesel backup, but the question is how much diesel are you going to keep on site,” Howell says. “So propane was a great alternative for this particular site.”

In addition to being cleaner, propane CHP units are also much more efficient, converting more than 80 percent of fuel into useful electricity and heat.

For some facilities, operating on CHP has reduced operating costs, helping achieve a fast ROI, though that wasn’t the motivation for Rincon Beach Resort, Howell says.

“This was really more of a resiliency play,” he adds.

Related: The Ultimate Guide to Commercial Generator and CHP Retrofits