The Challenge
Guarantee the supply of power to the island after the failure of one of the generation units
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Virgin Islands Water and Power Authority (VIWAPA), the electric and water company on the island of St. Croix, one of the U.S. Virgin Islands, is pursuing a long-term, multi-phased plan to modernize its installed capacity to make itself more efficient and environmentally friendlier by transitioning to liquefied petroleum gas (LPG) generation. After one of their old generation units suffered a mechanical failure, it was necessary to install a new plant in order to avoid power outages. VIWAPA needed a fast, safe, and reliable solution that met the plant's technical requirements as well as the strict environmental requirements set by the U.S. Environmental Protection Agency (EPA).
Key Facts
- $6 Million saved in two years
- 20 MW of LPG-fueled power
- 26,000 users benefited
The Solution
20 MW of LPG power with a unique design for compliance with strict environmental regulations
Aggreko designed and installed a solution that provided 20 MW of power with 18 highly efficient 1.2 MW NGG (Next Generation Gas) generators powered by liquefied petroleum gas, or LPG (HD5), which is transported to the island of St. Croix using tankers. One of the benefits of NGG generators is their ability to operate using a wider variety of gases, which was essential for this project since this solution needed to operate using LPG (HD5).
On the island, the demand for power can change by 40% between day and night due to high levels of commercial activity during the day. Flexibility was key. Our generators ensure greater energy efficiency and provide a seamless power supply in the face of changing demand. To comply with the requirements of the Environmental Protection Agency (EPA), we installed an exhaust system consisting of four 75 feet high (25 meters) smoke stacks that are connected to the generators. The performance of this system is continually monitored on-site by the EPA's Continuous Emission Monitoring System (CEMS), which tracks the quality of emissions released by generators.
Lower emissions and noise levels enable companies to comply with the most demanding environmental regulations. Furthermore, the inclusion of power generated with LPG allows the island of St. Croix to meet its carbon emission reduction targets. One of the unique safety features of this project is the anchoring system installed at the base of the generators and the smoke stack system, which enables this equipment to withstand the impact of hurricanes up to Category 4.To ensure that the gas reaches the optimum temperature required for the best performance of our generators, we included a cooling system with chillers and heat exchangers. This system uses environmentallyfriendly R134a refrigerant gas. This comprehensive, low-emission solution demonstrates that Aggreko is on the right track with regard to the energy transition, a global trend to promote emission reductions.
The Impact
Reliable and safe power with lower emissions and fuel costs
The efficiency of the Aggreko plant contributes to reducing both emissions as well as fuel consumption, which meant a saving of approximately $6 million dollars during the first 2 years for the customer. The population of the island of St. Croix benefited from the opportunity to receive quality power safely and without interruption, which enabled them to live their lives as normal.