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Symposium 2013

Proposal - Elements of a Sustainable Future Energy Mix

The Challenge

The use of renewable energies is supported by many countries, while the highest growth is observed in the power sector. By 2017 more than 70 countries are expected to deploy renewable energy technolog ...

The use of renewable energies is supported by many countries, while the highest growth is observed in the power sector. By 2017 more than 70 countries are expected to deploy renewable energy technologies (IEA 2012a). Germany is a pioneer in using and developing renewable energy technologies. In 2011, renewable energies contributed to 20% of electricity and 10% of heat use (BMU 2012). Several policies measures have been put in place to realize a transition of the energy sector towards renewable energies (so-called “Energiewende”). While major energy producers as well as small scale producers have invested into renewable energy sources, the “Energiewende” also causes some challenges. Energy prices have increased considerably in recent years, partly caused by higher costs, mainly subsidies of renewable energies. New infrastructure is needed to cope with different spatial and temporal availabilities of energy. While the public generally favors the support of renewable energies in the context of climate change mitigation, social acceptance to implement projects (constructing new power grids, or plants) at local levels is critical.

"Everything needs to change, so everything can stay the same!" This piece of wisdom is from Guiseppe Tomasi di Lampedusa's novel "The Leopard".

In terms of the future energy mix this means that it has to be primarily sustainable. The German energy turnaround may be the role model. It attempts to find a quick path to a climate friendly and sustainable energy policy.

But energy is also a production factor that determines a country's competitiveness. This urgently needs to be addressed, also in Germany. The energy mix is likely to play a key role in the security of supply. The total global supply, with a wide energy mix, will also impact the German energy situation in the future. CCS, fracking and innovative fossil-fuel based power plants cannot be discarded as topics.

In some cases, the energy turnaround has led to increased uncertainty. The first few years have revealed a number of different issues and a need for corrective action as well as the opportunities for a sustainable energy mix in the coming decades. A sustainable energy policy will not be able to focus on one energy carrier alone (renewables). There are significant challenges, but we must persevere.

According to the experiences of the past 20 years, the various energy sources in Germany play a different role with various development opportunities on the path towards a sustainable energy policy. They suggest that the primary renewable energy can only be onshore and offshore wind:

-          onshore wind, as it is the renewable energy with the lowest comparative remuneration, apart from hydroelectric power;

-          offshore wind receives a higher rate of remuneration but also has the highest full load hours, comparable to medium load power plants.

All other renewables are either too expensive or too volatile (photovoltaics with only 950 full load hours), too land intensive (biomass, although with up to 7,000 full load hours) or are too risky (geothermal).

The growth of renewables leads to another challenge: electricity at the wrong time at the wrong place. In order to balance this renewables volatility, in the future, a higher portion of renewable electricity must be able to be stored indefinitely and the base load must be secure.

By 2040 this storage capacity must be increased to 40,000 GWh of electricity (500 times more than today) for an energy demand of 15,000 MW. This immediately poses the question of whether these stores will be passed on to the public via the electricity price or to those originally responsible for the storage demand, the EEG plant operators.

There is also the principle option of storage using hydrogen as a storage medium, which will ultimately also unburden the electricity grid. Hydrogen provides five options:

-          Hydrogen as a product, esp. for the chemical industry in order to replace the "black" hydrogen from the steam reforming of heavy oil.

-          Or hydrogen for combustion and cold oxidation (fuel cells),

-          For electricity/heat production (methanisation) and as fuel (traffic).

However, serious questions concerning efficiency and costs still have to be answered.

Electricity that is produced and cannot be stored must be able to be distributed in Germany and to the European grid via interconnectors. Conceptual considerations on the smart grid with smart metering will be able to complement this but cannot act as a substitute, so there is no way around transmission lines. In addition, smart-grids will only reach any relevant size in the future.

Another essential topic hast to be emphasised: The grid expansion. It cannot wait for the necessary storage capacities, rather both must take place simultaneously. In a country with federal structures, as is the case in Germany, this requires national planning and implementation rights. However, the aim must also be to reach agreement at a European level.

Last but not least a better integration of all measures into the European market. As much market as possible, as much regulation as necessary – this is also a requirement for cheaper prices, more investment and more innovation with the objective of a sustainable energy mix. It also accords with the guideline from the beginning of the energy turnaround: As much carbon dioxide prevention as cheap as possible.