SIEMENS

In the aftermath of the nuclear power plant disaster in Fukushima, Japan, the German government decided to gradually shift to an energy system based on renewable sources. Plans call for the share of electricity produced this way to reach 35 percent by 2020 and 80 percent by 2050. How can Germany achieve these goals?

Kohler: This long-term strategy is in line with Germany’s energy transition process initiated in 2000, although it also accelerates the pace of the transition, which presents a huge challenge. The transformation of the energy system in a highly industrialized country has to be organized in a manner that makes sure we remain internationally competitive as an industrial location. On the one hand, energy consumption must be reduced through energy efficiency measures. At the same time, renewable energy sources must be intelligently integrated into the system. This will require expanding the grid infrastructure, developing new storage systems, and introducing smart grid components. The electricity we generate in the future will be generated by millions of distributed power plants that will often produce electricity at the same time, which means they will function like a single giant generator. We also need to build conventional power plants in the 10,000 MW range in order to ensure supplies.

What are the challenges here?

Kohler: The energy transition is a highly complex project in terms of its impact on society, technologies, and the economy. Up until now, we’ve used energy carriers with a high energy density — natural gas, oil, uranium, and coal — all of which are easy to store. The transition is complicated because renewable energy sources such as wind and solar power don’t always produce electricity when it’s needed and are often located in regions some distance away from where the power is needed. Their annual use times are relatively short as well. In Germany, photovoltaic systems, for example, only generate electricity for an average of 850 full-load hours per year. So we need to install a lot more capacity, and we also have to expand the grid at all voltage levels and make it more intelligent. In addition, we need to have more energy storage devices, some of which still have to be developed and made marketable. If 50,000 megawatts of solar power and the same amount of wind energy are fed into the grid in 2020, it will not be possible to sensibly integrate such a large proportion of fluctuating power generation within a national system. That means we have to intensify our work with neighboring countries in areas such as the use of pumped-storage hydroelectric facilities. A paradigm change is also required, because along with improving energy efficiency we also need to focus more strongly on the demand side of the equation and coordinate energy production and consumption more effectively with the help of demand-management systems.

Is it really possible to effectively manage such a complex project?

Kohler: The pace of the energy transition poses challenges for which we still don’t have complete solutions or the required experience. I believe we can accomplish the transition — but we’re going to need a roadmap that includes the milestones that must be reached if we’re to achieve our goals and make implementation as efficient as possible. These milestones must be defined for all aspects of the energy transition and take into account the impact they will have across all systems, because the mutual effects will be substantial. The German government wants to see a million electric vehicles on the road by 2020, for example — but all of them need to run on electricity from renewable sources if the whole thing is to make any sense environmentally. That means we need to have more intelligent networks to ensure that the grid remains stable, and this will require more networking between all the key players — meaning governments, business, and consumers.

What do you think our energy system will look like in the future?

Kohler: We need to closely examine what’s going to happen over the next 10 to 20 years in particular. We know the technologies that will be involved and we can estimate which of them will be available and which ones won’t. However, trying to describe our energy system in the year 2050 would be somewhat presumptuous. We have to make sure that the system isn’t rigid but can instead be easily adapted in line with future developments such as electricity storage by means of electrolysis and hydrogen. We can plan everything up to 2030 and it makes sense to define our long-term goals, but we can’t say today which technologies we’ll have to use in order to achieve those goals. We also have to radically change our focus from the energy supply itself to energy services. We have to create the political and economic conditions that will allow us to design our energy system efficiently. The advantages of this for industry lie in lower energy costs and greater competitiveness. Along the way, we will be able to enter new markets with our technologies, because efficient energy systems are in great demand all over the world.