A matter of Pride

A scheme is underway being hailed as “the world`s largest green energy project. The initiative will see a private consortium build a transmission line capable of transmitting 4000 MW of hydropower from Oregon to Nevada. An important part of the project is the use of composite materials in the transmission cables.

PEI report

Think of recent trends in the US power market and distributed generation is one of many developments that spring to mind. So when a company announces that it is to embark on two 850 mile-long high voltage transmission line projects, it seems a little unusual. But that is just what Nevada-based Composite Power Corporation is planning.

In February 1999, Composite Power announced that it will build, own and operate two high voltage transmission lines, one running from Montana to Wisconsin, and the other from The Dalles, Oregon to Las Vegas, Nevada. Both lines will be among the first privately-owned transmission lines in the USA.

The Montana to Wisconsin transmission line will transmit power from four 500 MW coal-fired merchant power plants which Composite Power will construct with the help of selected joint venture partners. The Oregon to Nevada line, called the Pacific Region Interconnect for Deregulated Energy (PRIDE), will transmit renewable energy from generation projects that Composite Power will also develop with various partners in what the company has hailed as “the world`s largest green energy project”.

A composite approach

Established in 1990, Las Vegas-based Composite Power labels itself as “an environmentally-friendly energy infrastructure company”. The company carries out research on composite materials that have been used over the last 50 years by the aerospace industry, and develops, manufactures and markets utility power poles and related hardware from these materials. Composite has also developed a breed of power cable that combines the current-carrying capacity of aluminium with the strength of composite materials. It is these products that will be at the heart of the company`s two planned transmission projects.

Like the market players making gains in the growing distributed generation market, Composite sees many advantages in the deregulating US electricity market. Through its utility pole and power cable business, it aims to become a major provider of energy in the deregulated marketplace within two to three years.

The Montana-Wisconsin project will see Composite, along with several partners, developing four 500 MW coal fired power plants in Bear Creek, Montana, at a cost of around $1.5 billion. In late 1998, Composite closed a deal to purchase the mineral rights to over 250 million t of coal reserves in the area. The company will develop the coal mine and power complex in Carbon county, restoring the Smith Mine site and opening a visitor centre. Around 200 jobs will be created at the site.

The Montana-Wisconsin power transmission line will be constructed at a further cost of $850 million. However, Composite estimates that the line will deliver power for a competitive ٗ/kW, compared with ٘-9/kW for many state utilities.

Pride of place

The PRIDE transmission line, nicknamed the “green line”, will run from The Dalles, Oregon to Las Vegas along an existing right of way. It will be capable of delivering up to 4000 MW of power. To build the line, Composite Power plans to establish a subsidiary company. The $1.3 billion cost of the project, which includes two DC inverter stations, will be financed through equity end users and financial guarantees from the owners of the subsidiary company. Composite Power will manage the project, while Dames and Moore will carry out the environmental impact study and Fluor Daniel will be the construction manager.

Composite anticipates generating substantial revenues from transporting power from hydropower plants in the northwest USA to the rapidly growing markets in the southwest. It will market the power under long term guaranteed contracts with equity end users and regional utilities. The northwest markets generally have an excess of generating capacity and the price for power in the southwest exceeds that in the northwest by three to four times. In addition, in the cold winter months, a surplus of power is available in the southwest which can be transmitted to the northwest.

For example, dams along the Columbia River on the Oregon-Washington border, supply local industries with cheap power during the day. However, a lack of interconnections with high voltage regional power grids means that the utilities are unable to move and market this power at night when local demand drops. Composite Power believes that its green line will change this.

Other generating capacity supplying the green line will be several hundred megawatts of solar power in Nevada`s Death Valley, a 250 MW wind farm in Washington state, and a pumped storage hydropower facility in southern Oregon. Composite`s partners in developing such renewable project include MinneSolar Corp., Siemens Solar Industries, Duke Solar, Stirling Energy Systems and W. Brandt Goldsworthy & Associates.

Going green

Composite Power was founded in mid-1990 by Roger McCombs, who realised the existence of a market for non-conductive utility poles given the dangers faced by utility linemen. The company now manufactures patented composite-based utility poles that are lighter and stronger than wood poles, as well as a line of composite products making up a complete energy delivery system comprising fasteners, pole caps, bottom plates and structural T-brackets. The poles are compatible with the company`s own composite system components as well as existing pole line hardware.

The composite poles are manufactured by a patented process known as pultrusion, a single-step continuous reinforced plastics raw materials conversion similar to extrusion where composite materials are pulled through a heated die. A pultruded composite pole meets or exceeds the current standards for wood poles, and in spite of the high cost of composite materials, Composite Power believes that their advantageous properties will help to solve several economic, safety and environmental problems faced by the utility industry today.

Every year, US utilities spend around $4 billion buying wood poles treated with toxic chemicals; more is spent replacing aging wooden poles. According to Composite Power, finding pole-quality trees is becoming increasingly more difficult. Composite utility poles do not require preservative treatment, overcoming these problems.

Another advantage of the composite system is that the power lines can be placed closer together than they can on traditional delivery systems. This not only means that potentially harmful electromagnetic fields are reduced, but also that up to 70 per cent more power can be delivered over the same right of way. In addition, existing right of ways containing underground natural gas pipelines can be used for overhead power transmission without fear of causing pipeline corrosion.

Other advantages of the composite system include:

•Minimal maintenance is required

•It is non-conductive, non-corrosive, waterproof, unaffected by temperature changes and soil acidity, and reduce lightning outages

•Poles are lightweight – 25 per cent the weight of wood and ten per cent the weight of concrete. Considerable transport savings can therefore be made: the poles can be airlifted to remote locations by helicopter

•The occurrence of accidents is reduced

•Poles can be extended to as high as 36.6 m (120 feet) while remaining mechanically stable with only a 12 cm (30-inch) base

•Composites allow for more flexibility in power line construction and are guaranteed for 100 years.

Composite cables

Composite materials also form an important part of the transmission cables to be used in the green line and Montana-Wisconsin projects. Working with Brandt Goldsworthy, a leader in composite technology, Composite Power has developed a transmission cable comprising aluminium wrapped in a composite sheath. Optical fibres are also added giving the transmission line `intelligent` properties.

Aluminium is a relatively inexpensive material and has very good conductivity approaching that of copper. However, its poor mechanical strength has restricted it from being used in power transmission applications. The use of an outer wrapping of composite material strengthens and stiffens the aluminium cable, and the low thermal expansion coefficient of composites constrains the expansion and contraction of the aluminium. The lines are expected to be able to deliver more than 50 per cent more power than similar diameter cables

The transmission line will also be able to diagnose problems along its length with the presence of a glass fibre optic wire running through its centre. This will monitor the line for faults, damage and hotspots, and also opens up other possibilities for Composite, including telecoms networks.

Composite Power is continuing its working relationship with Brandt Goldsworthy. The two companies recently signed a memorandum of understanding to develop an integrated composite materials manufacturing facility that could be located in Richland, Washington. Composite and Brandt Goldsworth say that this facility will be the largest of its kind in the world, and will manufacture composite products and conductor technology including the aluminium-composite cables.

Composite believes that a vertically integrated manufacturing facility, will allow it to better meet customer needs, particularly in terms of cost. The integration of its manufacturing processes, including the production of glass fibres from nearby raw material sources, will help the company avoid fluctuations in the cost of glass fibre.

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Figure 1. Traditional utility transmission structures could be a thing of the past with the appearance of composite products on the market

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Figure 2. The PRIDE transmission line will run from The Dalles, Oregon to Las Vegas

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Figure 4. Composite Power`s ystem allows lines to be placed closer together, reducing electromagnetic fields and transmission tower footprint