Much attention has focused on improving the appearance of overhead lines with the goal that these should have as little adverse impact as possible on their surroundings.
But what about substations and converter stations? These can occupy large tracts of land and are filled with structures and equipment that also impact natural landscapes. Should aesthetics and reduced visual impact play a role in their design as well? Or, is the better strategy to ensure these are sited far from public view?
INMR presents examples to illustrate what some power supply utilities have done when confronted with this choice.
Substations and converter stations are generally designed around technical requirements, safety and cost. Appearance has not normally been a factor since these are typically located in areas with limited human presence.
Unfortunately, a substation’s public exposure can change significantly over the decades. Once unpopulated areas become new residential communities or commercial neighbourhoods. Eventually, substations with no aesthetic component can find themselves surrounded by the public and become a target of disapproval and possibly vandalism.
With this in mind, aesthetic and minimalist designs or unique architectural facades can help ensure greater public acceptance of substations over the long term. At the same time, these can also help project a modern and progressive image for the power supply company that operates the station.
Below are several examples where consideration of appearance played a decisive role in substation design and architecture.
Substation in Seville, Spain
The 1992 World’s Fair in Seville focused on futuristic architecture and offered a unique opportunity for the local power utility to showcase design excellence in both overhead lines and substations. Nearly 30 years later, these structures have retained their original appeal and helped a large substation become an accepted part of an urban neighbourhood of contemporary buildings.
Substation near Helsinki, Finland
Finland is a country noted for excellence in design. This tradition was applied in the early 1990s to three prominent transmission towers sited near a busy highway interchange and also to a substation near the country’s major international airport in Vantaa. The aim was to reduce the station’s visibility against its forested surroundings.
By today’s standards, the solution may not seem so remarkable. Yet in the day it represented one of the power industry’s first acknowledgements that visual impact of a substation matters to those who live nearby or pass it regularly.
Regentsville Substation in Australia
During the mid 1990s, the network operator in New South Wales, Australia wanted to build a classical mesh substation at the strategic confluence of existing 330 kV and 132 kV lines. The pristine region where the station was to be sited was the exact type of place where resistance to a new air-insulated substation could be expected. The goal of station designers was therefore to create a layout that would help obtain public approvals without resorting to the costly alternative of a GIS solution.
Since land surface was not an obstacle, this was achieved by controlling structure heights in order to understate overall visual impact. Moreover, any structure above a certain height was painted green while incoming conductors were grit-blasted to remove sheen. Finally, a pond and buildings resembling a country club were added to help the substation better fit the area’s character and traditions.
Substation near Montreal, Canada
A key GIS substation located along one of the main highways connecting to downtown Montreal was designed around concrete structures and elements reminiscent of prominent buildings along the route. This helped the facility to better blend into the area rather stand out.
Substation in Mexico City
Veronica GIS substation in Mexico City is sandwiched between residential and high-rise commercial buildings. Since most of the incoming feeders for the pre-existing GIS were oil and paper cable, this technology was converted to XLPE cable directly outside the structure to avoid presence of oil near the GIS. A recent retrofit project saw new incoming XLPE cable going directly to new GIS facility linked to two 230/23 kV transformers.
The showpiece of this latest refurbishment is an architecturally elegant and expensive structure that houses the 230 kV GIS equipment and which was designed to fit in among the modern buildings nearby. Part of the reason for the high cost was that it had to be engineered with special damping equipment to move as a single unit thereby protecting the GIS inside from excessive movement and allowing it to remain operational even during earthquakes of magnitude 8 or more. The height of the new building reflects the land constraint since it houses not only the GIS on one floor but also the metal-clad switchgear directly above it on an upper floor.
Converter Station in Italy
The ±500 kV SAPEI Converter Substation is located near the town of Latina in central Italy. The complex, which includes a 380 kV air-insulated substation and switchyard, filters, valve halls and fully enclosed DC halls is bordered on one side by the sea and a 1000 MW cable connection to the island of Sardinia. The other side faces a coastal highway serving nearby tourist areas.
Due to the scale of the DC halls, maintaining low visual impact was not an option. Instead, the station’s architectural cover aimed to project a futuristic facade complete with nighttime light show.
GIS Substation in Belgium
The double circuit 380 kV line that transports power between the substation in Zeebrugge and the Horta Substation near Zomergem in Belgium was not the type of project that might normally attract attention. Yet with only 100 towers and covering but 37 km of overhead line along with 10 km of underground cable, it became among the most watched projects in Europe. What made the project so interesting is that it served as an example of how a power utility can adapt to meet the challenges now faced by the industry – from helping respond to the climate crisis to successfully dealing with opposition to new lines and substations. In this context, the processes and solutions adopted offered a unique opportunity to study how these challenges can be approached and overcome.
The project terminates at a substation in the coastal city of Zeebrugge where a uniquely designed GIS substation was sited at a low point near a highway overpass to reduce visual impact. Notwithstanding this, it still has a bold sweeping design using a wooden facade intended to resemble the hull of a ship. As at other substations on this project, GIL technology was utilized to reduce distances between incoming phases and allow for a smaller overall ‘footprint’.
Cable Termination Station in Denmark
Cable transition stations can present substantial visual impact, especially given that these are often sited at sensitive points where overhead lines are deemed unacceptable. With this in mind, Danish TSO, Energinet, created a futuristic metallic enclosure for a new cable transition station on the Jutland Peninsula that was part of a project to replace the former overhead line crossing to the rest of Denmark with subsea cable.