The term ‘smart grid’ is increasingly being used in discussions about our clean energy future, but what does this term signify?

Dr Julliard explains that the smart grid is not one single technology, but comprises a range of components. He says that the smart grid is, essentially, the transformation to a highly interconnected network between electricity consumers and suppliers. The network is intelligent, or smart, because it uses continuous monitoring and digital control, and is able to apply this information to use energy more efficiently.

Dr Julliard says that the smart grid will continue to evolve over time, as existing infrastructure is upgraded to integrate new, ‘smarter’ technologies, a process that he notes is already taking place in countless projects around the world.

Cross-continental networks

Along with other industrial companies, Siemens Energy is participating in the Desertec initiative to provide sustainable power to Europe, the Middle East and North Africa.

Electricity generated in the desert regions of the Desertec project, through renewable sources such as wind and solar thermal, will require high-voltage direct current (HVDC) transmission technologies for transportation over distances of approximately 2,000 kilometres from North Africa to consumers in Europe.

“Siemens has already implemented this sort of infrastructure in China,” says Dr Julliard. This project involved the transmission of 5,000 megawatts (MW) generated by hydro power plants in the country’s interior to megacities on the coast, located 1,400 km away. The HVDC technology has very low transmission losses, which Siemens says reduces the amount of CO2 released into the environment by three million metric tonnes per year.

Virtual power plants

Siemens is also developing virtual power plants in which collective households, buildings and farms that are producing excess renewable electricity are able to sell to the network via decentralised management system software. To date, Siemens has completed three projects of this type.

“In Sauderland in Germany, we have linked nine hydro power plants along the Lister and Lenne rivers into a virtual power plant; we are also currently working with universities in the United States to link their small power plants so as to optimise their costs,” says Dr Julliard.

SIPLINK – the smart grid link

In Ulm, Germany and New Ulm, Bavaria, a smart grid link (SIPLINK) transforms the electricity current from one grid into direct current. It then changes this direct current into alternating current, matching that of the other grid. This means that in peak-load hours when there is the highest consumption of electricity, the utility company can simply take the necessary balancing power directly from the now integrated grid.

Indeed, Dr Julliard emphasises that it is imperative to have an integrated approach to this new, smarter era of electricity generation and distribution.

The smart grid will not only improve the efficiency of the electricity network, but technologies such as smart meters will (and have already begun to) improve consumer understanding of how to be smarter in their use of electricity.

The electric vehicle will also be an important part of the smart grid, providing a potential storage solution for power from renewable energy sources. In the future, when millions of electric cars are connected to the supply network, they will be able to buffer the fluctuating supply of solar and wind power.

As to what steps need to be taken to ensure that the smart grid takes off, Dr Julliard says the technology is readily available and, quite simply, its implementation will be driven by the pressures of climate change and depleting energy resources.