While today’s investments in renewable energy generation are mainly driven by legislation and political directives, this will change. Today energy is mostly generated by burning fossil fuels, but in addition to the serious impact this has on the environment, these resources are finite. As they become harder to find and harvest, sustainable emissions-free renewable energy generation will undoubtedly come to play an important role in the energy business.
Wide-scale integration of renewable resources is so far the only sustainable, long-term solution to problems of finite energy supplies and soaring energy demand, which at current growth rates is expected to double every 30 to 40 years.
There are challenges to large scale integration of renewable generation into the energy mix. To be viable, projects have to be installed where they can be fully and efficiently utilized, and such locations are typically far away from load centres that need the energy the most. Hence, integrating renewable generation on a large scale will also require a considerable increase in power transmission capacity and efficiency.
HVDC transmissions already deliver electricity generated by hydro, wind, and solar plants to millions of consumers every day. The best generating sites are usually in remote areas, so the electricity generated from mountaintops, deserts and seas often crosses vast distances to get to where it is needed most. HVDC is the most reliable and efficient way of getting it there. Low loss DC transmission technology ensures virtually all renewable generation reaches consumers.
For example, a 2,000-km long DC transmission line at 800 kV loses about 5 percent of its power, while the power losses in an AC line of similar voltage are about twice as high. HVDC is the only option for the underground transmission of power over distances of more than about 50 km.