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“The reliability of our operations is borne out by our ability to deliver our services 24 hours a day, 365 days a year.”MIKE JESANIS, GROUP DIRECTOR
Securing an alternative energy source
National Grid Grain owns and operates the liquefied natural gas (LNG) import facility located at the Isle of Grain, in Kent.
Commercial operations commenced on 15 July 2005. As at 31 March 2006, on the instruction of its customer BP/Sonatrach, 19 gas shipments had been received and around 16.1 TWh (terawatt hours) of gas delivered into the gas network. The facility currently has the capacity to import and process 3.3 million tonnes of LNG per year.
The business is incentivised to maintain plant availability and reliability and was available for 99% of the Winter period.
Reliability Enhancement Programme
The US electricity business has launched a five-year programme to address its ageing system and strengthen its infrastructure to reduce the number and duration of outages.
National Grid’s ‘Reliability Enhancement Programme’ utilises data gleaned from geographic information systems and other technologies in which the Company has invested that enable better identification of problem areas and the steps necessary to fix them.
The key focus areas for the next three years include significant increases in vegetation management, improving protection of the system from animal contacts and lightning, and ‘hardening’ of circuits. Hardening improves the ability of a circuit to withstand exposure to the elements through targeted replacement of deteriorated components and equipment.
The Reliability Enhancement Programme also includes ongoing condition assessment of the distribution system as well as increased inspection and maintenance programmes and substation refurbishments, expansions and rebuilds.
Located off the Massachusetts coast, the island of Nantucket is a popular travel destination and place to own property that, over the past few years, has seen growth in demand for electricity rise dramatically.
As a result, National Grid has installed a second submarine cable system at a cost of more than $40 million to deliver electricity to the island. Nantucket was previously served by a single 46 kilovolt, 26-mile underground and submarine distribution cable connected to the regional transmission grid on Cape Cod. This cable went into service in late 1996, replacing diesel generating units and ushering in a new era of reliable electric service for customers on the island.
The second cable system consists of a new connection to the regional transmission grid, more than five miles of underground cable on the mainland and the island, and roughly 27 miles of submarine cable that traverse Nantucket Sound at a depth of approximately eight feet below the seabed.
National Grid has undertaken major expansion projects at its Ward Hill and Wachusett substations in northeastern and central Massachusetts respectively. Both projects, which include the addition of new transmission equipment and upgrades of existing transmission lines, as well as distribution improvements at Ward Hill will greatly enhance the reliability of New England’s bulk transmission system. They will also improve local service for our customers.
UK gas distribution uses, where possible, no-dig pipe-laying techniques to replace old cast iron pipe with new plastic pipe. One of these methods is known as ‘live main insertion’ which enables the replacement of mains under live gas conditions and avoids the need to dig long trenches. Instead, construction crews excavate small sections at two ends of a length of cast iron pipe and insert the plastic replacement pipe into the iron pipe. This avoids the need to interrupt supply to customers and reduces construction costs with significantly less excavation of roads, driveways and gardens. Consequently, this reduces inconvenience to the public and customers from construction work.
This process has been shared and adopted by our colleagues in the US and received the 2005 Technology Project of the Year Award from the Technology Alliance of Central New York.
Last year, UK gas distribution invested £444 million in the reinforcement, extension and replacement of the UK gas distribution network compared with £359 million in 2004/05 (this excludes the investment in the four regional gas distribution networks that were sold on 1 June 2005). Replacement expenditure increased from £239 million in 2004/05 to £295 million in 2005/06 in line with the planned increase in the long-term cast iron mains replacement programme agreed with the Health and Safety Executive. This enabled us to decommission over 1,710 km (1,063 miles) of old gas pipe in 2005/06 compared with 1,458 km (906 miles) in 2004/05.
Operating from a newly established control facility, the Gas National Control Centre (GNCC) is responsible for operating Great Britain’s gas transmission network safely, reliably and efficiently, managing the flow of gas from suppliers to customers. We ensure that all gas entering the gas transmission network meets the appropriate quality standards. We operate the system in accordance with appropriate legislation and the Health and Safety Executive safety case, while facilitating equitable and transparent access to all market participants.
GNCC operates 4,300 miles of high pressure transmission pipeline across Great Britain, facilitating the transportation of around 100 billion cubic metres of gas per year to power stations, industrial and commercial customers and approximately 20 million domestic customers.