The future of electric energy

In the past few years, European countries have shown a willingness to move away from nuclear and carbon-based energy sources. This has led to the development of renewable energy. But it's not clear whether this commitment to renewable energy will continue.  Though the European Commission seemed interested in pursuing a low-carbon economy a few years ago, it now seems more interested in a low-cost economy. "Why?" asks Damien Ernst. “Because the price of energy is undoubtedly one of the factors which led to Europe's deindustrialisation. Energy prices are critical to industry. The US, for example, followed a low-cost policy even as they increased their energy independence. The result is much lower energy prices: 30 euros per MWh in the US compared to around 55 euros in Europe!” The US has in fact developed an energy mix that is based on three energy sources: shale gas, nuclear energy, and renewable energy. However, renewable energy has only been pursued under advantageous circumstances. For example, solar energy is produced in areas that receive a lot of sunlight, and wind farms are located on the Atlantic coast - and not the other way around!  “In Europe, on the other hand, the effort has been spread among different countries (since the objective is to have 13% renewable energy in the energy mix); this is not a policy intended to maximise wealth at the European level,” says Damien Ernst. “For the same investment, PV panels in Seville produce twice as much energy per year as panels in our area. The European energy policy seems very amateurish. There are some good intentions, but the policies that are implemented are naive, and disastrous in the long term. In the end, a great deal of money is wasted, and the renewable energy sector hasn't even grown enough!”

Solar potentialIn other words, if Europe wants access to low-cost energy, it must renew its policy by targeting the most advantageous renewable energy sources:  for example, solar farms in Southern Europe, wind farms in the Atlantic Ocean or Baltic Sea, and of course, the very efficient wind farms in Greenland. This is what is recommended in Ernst’s article "The Global Grid". The installation of large wind farms in Greenland, along the coast where wind speed is almost constant and above 8 m/sec, could become the trigger element of this Global Grid since they are located halfway between Europe and the USA. Given the time difference between the US and Europe, it would make sense to build links to both continents and play on price variations to sell electricity mostly where the demand is highest. But other projects are also possible, such as exploiting the immense solar potential in North Africa -the Desertec programme - or the Gobi desert in Asia (Gobitec). It's this interconnection of renewable energy sources at the global level that will allow us to smooth out their variability.

“However, we don't have any experience in managing these different network layers simultaneously,” admits Damien Ernst.  “And one of the difficulties stems from the fact that the Global Grid is made up of long distance links which transmit ultra high voltage direct current rather than the alternating current which is used by most other networks. The advantage of transporting direct current is to reduce Joule effect losses. In fact, the first electrical networks in the 19th century used direct current, but then they switched to alternating current since it was necessary to increase the voltage to transport energy over longer distances without prohibitive energy losses. At the time, the only systems that could increase and decrease voltage were transformers, which only worked with alternating current. Nowadays, power electronics makes it possible to modify direct current voltage as well. If we had had the existing technology at the time, we never would have developed alternating networks. But energy losses aren't the only problem. Many of the Global Grid's cables will be undersea. And a cable that transmits alternating current combined with seawater forms a capacitor, which creates voltage problems that must be resolved by connecting inductors to the cables at regular intervals, which is very expensive. This isn't an option for the distances that will be covered by the Global Grid. We must therefore use direct current power.”

However, the Global Grid does present some problems.  In Belgium, there is the risk that we will further increase our energy dependence (but this would be the case regardless of the existence of the global grid). At the European and global level, it will be practically impossible to protect such an infrastructure against terrorism (even more so than petroleum and gas networks), making us vulnerable to a global blackout.

(1) The global grid, Chatzivasileiadis, Spyros; Ernst, Damien ;  Andersson, Göran in Renewable Energy : An International Journal (2013), 57

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