Ensure the island’s electricity supply after one of the generating units failed.
20 MW of energy produced as LPG, with a unique design to meet strict environmental regulations
Reliable and safe energy, with lower emissions and fuel costs
Client:Virgin Islands Water and Power Authority (VIWAPA)
Location:St. Croix Island, U.S. Virgin Islands
Sectors:Utilities
The challenge
The Virgin Islands Water and Power Authority (VIWAPA), the electricity and water utility on the island of St. Croix, one of the United States Virgin Islands, is delivering a long-term multi-phase plan to modernize its installed capacity, making it more efficient and environmentally friendly by transitioning to liquefied petroleum gas (LPG) generation.
After one of the older generation units suffered a mechanical failure, a new power plant had to be installed to prevent power cuts. VIWAPA needed a fast, safe and reliable solution that met the plant’s technical requirements, as well as the environmental requirements set by the United States Environmental Protection Agency (EPA).
The Solution
Aggreko designed and installed a 20 MW power solution with 18 highly efficient 1.2 MW NGG (Next Generation Gas) generators, fuelled by liquefied petroleum gas - LPG (HD5), which is shipped to the island of St. Croix by sea. One of the benefits of NGG-powered generators is their ability to operate with a wider range of gases, which was essential for this project, as a solution was needed that could run on LPG (HD5).
On the island, power demand can vary by 40% between day and night due to high levels of commercial activity during the day, so flexibility was critical. Our generators deliver greater energy efficiency and provide uninterrupted supply as demand changes. To meet Environmental Protection Agency (EPA) requirements, emissions are discharged through an exhaust system with four 25-metre stacks connected to the generators. The performance of this system is continuously monitored on site by the EPA's Continuous Emissions Monitoring System (CEMS), which tracks the quality of emissions from the generators.
Lower emissions and noise levels help meet the strictest environmental standards, while the use of LPG-generated power helps the island of St. Croix achieve its carbon emissions reduction targets. One of the project's safety features is the anchoring system installed at the base of the generators and the exhaust stack system, which allows the equipment to withstand hurricanes of up to category 4. To bring the gas to the ideal temperature needed for the best performance from our generators, a cooling system with chillers and heat exchangers was added, using R134a refrigerant gas, which does not harm the environment. A complete low-emission solution that shows Aggreko is on the right path for the energy transition, a global trend that supports lower emissions.
The Impact
Aggreko plant efficiency not only helped reduce emissions, but also fuel consumption, which delivered savings of approximately $6 million for the customer during the first 2 years. The people of the island of St. Croix benefited from receiving quality power, safely and without interruption, so they could continue their daily activities.