Major infrastructure investments focus on transmission and distribution

Paul Boughton

Major investments in new networks worldwide are being made to ensure better energy integration and flexibility both within and between different countries. Sean Ottewell reports.

Dutch company TenneT has joined a new 380 kV high voltage connection into the national grid of the Randstad380 South Ring. This ultramodern 'power highway' has been constructed using the latest technologies and includes a number of underground cable sections and TenneT's innovative Wintrack pylon design.

"The Randstad380 South Ring is an important addition in that it will enable us to meet the increasing (renewable) energy integration, cross-border connection and flexibility demands made of our national grid," noted TenneT ceo Mel Kroon.

The Randstad380 South Ring is part of a high-voltage connection spanning 80km, which includes the Randstad380 North Ring. The project is scheduled for completion in 2018. The North Ring will be constructed between the towns of Bleiswijk and Beverwijk. The South Ring stretches between the towns of Wateringen and Bleiswijk.

TenneT's investments in the Dutch high-voltage infrastructure for the next ten years will amount to EUR5 billion. Over the next ten years four large-scale projects - including the Randstad380 South and North Rings - and 300 smaller-scale projects will be carried out.

The company has also used a number of innovations during the project. One of these is the implementation of its in-house developed Wintrack pylons. Their design ensures a magnetic field zone over 60 per cent smaller than that of a connection using lattice pylons. In addition, the colour and slender design of Wintrack pylons minimises their impact on both the natural environment and the living environment of local residents: the pylons are much less intrusive visually, says the company.

A second innovation is that the 380 kV transmission grid includes long sections of underground cables; around the world, such grids are almost entirely above ground. By using underground cables, TenneT says it demonstrates a commitment to furthering the development of this new technology. The Randstad380 South Ring includes a total of 10.7km underground, sparing a densely populated area the significantly greater impact of overhead lines and pylons. The underground installation of a high-capacity 380kV cable over such a long distance is a world first, which makes the Netherlands a leader in the construction of innovative high-voltage connections, says TenneT.

In Canadian news, Bechtel has completed the Hanna Region Transmission Development (HRTD) project on schedule and under budget. The project to expand and upgrade ATCO Electric's electrical transmission system and infrastructure in Alberta included stringing 353km of 240 kV and 144 kV transmission lines, constructing more than 1200 new transmission towers, and building six new substations and upgrading 12 substations.

"The construction of the HRTD project has helped us meet the increased demand for electricity in the Hanna region due to industrial growth in the area," said Sett Policicchio, president, ATCO Electric Transmission Division. "We were pleased to work with a team that could skilfully manage construction in environmentally sensitive areas and cope with our diverse weather conditions."

About 60 per cent of the area where the transmission line was built passed through protected pasture, native grasses, and wetlands that are also popular wildlife breeding grounds. To minimise the impact, the project team used a mobile app to ensure that the field team had customised information about accessing land parcels and environmental regulations.

"The complexity of this project was in the logistics of constructing a variety of transmission-line segments over a vast geographic area, with varying site conditions," said Toby Seay, president of Bechtel's transmission business line. "Despite working miles apart, the Bechtel and ATCO Electric team worked in unison to develop innovative and sustainable solutions that ensured the safe delivery of the project with minimal environmental impact," he added.

The company is now supporting ATCO Electric's Eastern Alberta transmission line project. Bechtel will construct approximately 485 km of 500 kV high voltage direct current transmission line running from the Gibbons-Redwater area northeast of Edmonton to the Brooks area southeast of Calgary.

Offshore converter

In a separate development, ABB has installed the world's highest-voltage offshore converter station in the North Sea (Fig. 1). Alternating current electricity generated in three wind farms off the coast of Germany will be converted on the platform into high-voltage direct current (HVDC) for transmission to the mainland.

The 320kV converter station has an 800MW power transmission capacity making it the world's most powerful installation of its kind.

In a three-day operation, the 9300 tonne topside including the converter station was transported offshore by barge around 75km off the German coast. It was then lifted by the world's largest crane vessel Thialf and positioned on top of the already installed jacket.

"Putting such a huge platform in place is one of the most delicate operations in the delivery of an offshore transmission link, requiring strong cooperation between the many stakeholders involved," said Brice Koch, head of ABB's power systems division. "This is an important project milestone in the delivery of this HVDC offshore wind connection and we are pleased it went smoothly."

Brazil focuses on future needs

ABB has won an order worth around US$30 million (EUR23 million) from Furnas Centrais Elétricas to construct a new indoor transmission substation in downtown Rio de Janeiro to power the renowned Maracanã soccer stadium (Fig. 2) and the adjacent neighbourhood.

The Maracanã stadium was the world's largest when originally inaugurated in 1950, with space for around 200,000 spectators. It has been completely rebuilt for the forthcoming World Cup and, with a capacity of more than 75,000 people, is still the largest stadium in Brazil. It will host seven games in 2014 including the World Cup final.

Brazil is boosting its power capacity and enhancing its transmission and distribution infrastructure to ensure that its electricity grid can meet the needs of its expanding economy as well as the 2014 FIFA World Cup and the 2016 Olympic Games (Fig. 2). These sporting events are likely to place huge additional demands on the grid.

"These compact substations will enable additional power supplies required during the forthcoming global sporting events being hosted by Brazil and will reinforce the transmission grid for the future," said Brice Koch, head of ABB's power systems division.

ABB is to design, supply, install and commission the new indoor substation to replace a 40-year-old installation in Grajau, near the Maracanã stadium. Thanks to the compact footprint of the gas-insulated switchgear (GIS), the new higher-capacity facility can be built on the same plot of land as the existing substation.

At 63kA, the substation will have the highest short-circuit current interruption level of any GIS substation in Brazil. This rating refers to the maximum current that a circuit breaker is capable of interrupting to isolate a fault and protect the network. ABB will also install IEC-61850 substation automation, control and protection systems to enable local as well as remote control and monitoring.

Europe's largets intelligent network storage project

S&C Electric Europe, Samsung SDI and Younicos have signed a joint agreement to deploy Europe's largest intelligent network storage project onto a UK Power Networks substation, saving over £6m on traditional network reinforcement methods. By providing frequency regulation as well as load shifting, the project will also stabilise the grid much more effectively than traditional thermal generators, providing more space on the grid for clean, but intermittent renewable energies.

The fully automated 6MW/10 MWh smarter network storage (SNS) battery technology project will be installed at Leighton Buzzard primary substation, in order to assess the role of energy storage in cost effectively delivering the UK's carbon plan. The technology can provide a range of benefits to the wider electricity system, including absorbing energy, then releasing it to meet demand, to help support capacity constraints and to balance the influx of intermittent and inflexible low carbon technologies onto the grid.

The SNS project aims to carry out a range of technical and commercial innovations to facilitate the more efficient and economic adoption of storage. By contrast to other electrical storage projects, it will demonstrate storage across multiple parts of the electricity system, outside the boundaries of the distribution network. By demonstrating this multi-purpose application of 6MW/10 MWh of energy storage at Leighton Buzzard primary substation, the project will explore the capabilities and value in alternative revenue streams for storage, whilst also deferring expensive conventional reinforcement measures, such as transformers, cable and overhead lines.

The £13.2m project runs until December 2016.

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