The power broadband

Experts equate it to the powergrid’s equivalent of Internet broadband and China is aggressively pursuing leadership in this field. We refer to UHVDC or ultra high voltage direct current transmission of electricty across large distances.

When ready, China has plans to link its far flung west and east in a move to take power from renewable rich west to the power deficient east. Some see this as the technology that can eventually link Australia to Asia.

UHVDC is seen as best option to push large amounts of electricity across long distances with least loss. This will mean pumping above 800 kv along the lines and even beyond 10,000 MW soon, as planned in China. Losses can be as low as about 3% per 1000 km. High-voltage direct current transmission allows efficient use of energy sources remote from load centers.

To increase capacity of existing grid, reducing line cost (no need to support multiple phases and use of thin conductors), synchronise different AC systems, undersea cables, etc the HVDC is a good option.

However, HVDC would not be ideal for short distances and the inverters can be costly. Plus the technical difficulty in building DC ciruit breakers, are seen as some disadvantages.

There are two ways to view the situation. One, is to generate power where required using available resources. That is distributed decentralised generation. Two, generate where the resource is in plenty, be it wind or sun, and make it available where demand is most. That is where HVDC could play a big role.

What path should India opt for? Especially if we earnestly intend to increase the share of renewables.

Let us hear what the experts think on this.