Experiencing a world record first-hand
A personal view on ABB`s major milestone this summer, which sees extruded DC cable voltage boosted to 525 kV, the highest ever achieved
What if you were able to squeeze all the electricity generated by a huge wind park through a pair of power transmission cables so lightweight you could hold them in your hand?
Well now you can, because the ABB power cable team in Karlskrona, Sweden has done it!
Most people are aware by now that as CO2 emissions increase, our climate is getting warmer. Fortunately ABB recognized this fact a long time ago, and has spent years developing products and systems for emissions-free renewable energy generation to help mitigate the effects of a changing climate. Wind energy, both on-shore and off-shore, and solar energy are just two examples of such energy sources.
Once you have generated emissions-free power, then you need to get it to consumers. Because renewable power is usually generated far from consumption centers, it must be transmitted over long distances, either by overhead power lines or power cables.
Cables are the answer when you need to transmit power under the sea, or if getting a permit for overhead land lines is too difficult. Cables come in AC (alternating current) or DC (direct current) voltages. AC cables in the range of 50 or 60 Hz are used for transmission routes around 100 km long. Anything longer and power losses become too large, as the cable itself consumes most of the current.
ABB has been developing and making cables for DC voltage since 1954, when the Swedish island of Gotland was connected by DC cable to the power grid on the Swedish mainland. Compared to modern systems of this type, the voltage and power transmission capacity were not very high, at 100 kilovolts (kV) and 20 megawatts (MW). The insulation for that cable type, called MI (mass impregnated) cable, was paper tape soaked in a thick compound. While the maximum operating voltage of this product has been successively increased to the 500 kV range, the maximum operating temperature is still limited to 50-55°C. This limits maximum power capacity to about 2 gigawatts (GW), which is 2,000 MW, or 2,000,000 kilowatts (kW). A rather difficult jointing process makes MI cable less popular as a land cable, because many joints have to be installed.
In 1999, ABB introduced the world’s first extruded DC cable rated at 80 kV. Extruded cables are more robust, and because they operate at higher temperatures are able to carry more power. They are also easier and faster to install, which makes them the perfect option for land installations. Since its introduction 15 years ago, ABB has continually increased the voltage range of extruded DC cables. Until today it was 320 kV – the standard everyone else is now following.
Then in 2014 ABB announced a major milestone, which boosts extruded DC cable voltage to a world-record 525 kV, the highest ever achieved! A cable system with this rating enables electricity transmissions as high as 2.6 GW. Imagine up to three, large off-shore wind parks pushing their entire power generation output through a single pair of power cables, and you get an idea of the capability of this new cable!
It took a dedicated team of people drawn from different Business Units, Corporate Research Centers and an external cooperation partner several years to finally reach this milestone. The project was and is a powerful example of team work, and I am very grateful to have been a part of the process.
I am also totally convinced that this kind of team work is the key to ABB`s success – unreservedly sharing knowledge, creating new ideas, supporting each other when the going gets tough, celebrating hard won results, and growing friendships based on trust and respect.
One of the team’s key strengths was to never – and here I mean never, ever – give up! To relentlessly seek the facts, and to always believe in the project, and in ourselves. Many of my presentations now end with a slide from that time that I`m very fond of and which I’ve chosen to put at the top of this page.
- Video: ABB launches world´s most powerful underground and subsea power transmission cable system
- Video: Magnus Callavik – The 525 kV HVDC extruded cable breakthrough
- Blog post: From genuine challenge to world record
- Web page: ABB High Voltage Cables