Siemens Commissions New Transmission System Connecting NJ To Long Island
Erlangen, Germany — At the end of June 2007, well ahead of schedule, Siemens Power Transmission and Distribution (PTD) successfully commissioned a new high-voltage direct-current (HVDC) transmission link between Sayreville, New Jersey, and Long Island, New York. The HVDC system carries 660 Megawatts at a DC voltage of 500 kV. In July 2005, Siemens was awarded the contract to build the interconnection by Neptune Regional Transmission System LLC (RTS), Fairfield, Connecticut. After commissioning, Neptune RTS, owner and operator of the transmission system, will place the power link at the disposal of the local utility Long Island Power Authority (LIPA). Thanks to this HVDC submarine cable interconnection, Long Island will receive power from the grid of New Jersey in a low-loss and environmentally compatible way, which will help to cover a constantly growing power demand and strengthen the "backbone" of Long Island's transmission system.
For various reasons, environmental protection in particular, it was decided not to build another power plant on Long Island near the city in order to cover the power demand of Long Island with its districts Queens and Brooklyn which is particularly high in summer. The Neptune HVDC interconnection is an environmentally friendly, cost-effective solution for meeting this future needs. It provides access to mainly regenerative power sources, such as hydro and wind power. The low-loss power transmission is carried out via a combination of submarine and subterranean cable directly to the network of Nassau County which borders on the city area of New York.
A particular advantage of HVDC transmission technology when compared to constructing a new power plant or building a new conventional three-phase AC transmission line is the fact that the short-circuit power of the network does not increase; that is, no complex measures to upgrade the existing short-circuit capacity of the grid are required. In addition, fast acting control functions enable HVDC systems to help stabilize the connected networks, which constitutes a decisive benefit of this technology in the event of outages and blackouts in the system.
An outage of this kind which lasted over a week occurred in Queens as recently as in July 2006. It was caused by increased power consumption due to the operation of many air conditioners and, among other things, due to not sufficient power supply of this large area. The new HVDC connection between Long Island and New Jersey will provide a reliable solution to these problems in the future.
The project was carried out by a consortium of Siemens and Prysmian Cables and Systems. The total contract value was approximately 350 million euros, the Siemens share was approximately 180 million euros. Siemens, as the consortium manager, designed, manufactured, supplied and installed the complete set of HVDC equipment including converter valves, converter transformers, smoothing reactors, high voltage switchgears as well as communication and control equipment. Siemens was also responsible for the construction of valve halls and operations buildings. The consortium partner Prysmian supplied and installed a total of 105 km of submarine and subterranean cable.
Neptune RTS was founded as an independent developer with the goal of building commercial power transmission projects in the USA. In cooperation with Neptune RTS, Siemens as part of the development team was developing the project over the course of more than three years and made it fit for implementation. In addition to providing technological expertise, studies and engineering services, Siemens also supported its customer in the necessary approval process for the project.
After the system went into operation, Siemens will provide operation and maintenance services for the first five years. By delivering a complete package of supply, installation, maintenance and operation, Siemens provides a seamless single source for the customers' needs. This comprehensive expertise and capability fulfills the prerequisites for financing these kinds of complex supply projects on the free market of investments. Due to these projects, Siemens plays its part in the enhancement of global security and sustainability of power supply.
SOURCE: Siemens Power Transmission and Distribution (PTD)