Last week, a commission appointed by Germany's Chancellor Angela Merkel recommended that the country shut down all of its nuclear plants by 2021 and instead rely on other forms of power for its electricity, including renewable energy. This analysis finds that phasing out nuclear power would be 4.5 times harder than meeting Germany's ambitious 2020 emissions reduction goals for the electricity sector, while the country's 2020 renewable energy generation goals would fall 30% short of supplying enough power to displace the electricity currently provided by Germany's nuclear fleet.

Germany has pledged a set of carbon goals for 2020, primarily to reduce its carbon emissions by 20 percent of 1990 levels. To do so, the country has vowed to scale renewable energy to supply 35 percent of electricity demand, and to increase its economy's energy efficiency by 20 percent over 1990 levels.

However, phasing out the nuclear power sector, which currently supplies about one quarter of the country's electricity demand, would make meeting this emissions target substantially more difficult.

The graph below illustrates that the country's renewable generation goal falls far short of replacing the power currently supplied by nuclear power: a shortfall of 39 billion kWh. Further, if the country met its goal for renewable generation without any additional policies, it would fall roughly half-way short of meeting its combined emissions reduction and nuclear phase-out objectives.

Displacing nuclear while also shutting down enough fossil energy generation to meet the nation's 2020 emissions reduction goals would require renewable energy to supply 48-50% of Germany's energy supply in 2020, a roughly three-fold increase in electricity derived from non-hydro renewables like wind and solar power.

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Shutting Down Nuclear?

To fully replace nuclear power with renewable energy, the country would have to scale renewable energy to provide over 42.4% of the country's projected 2020 electricity demand, a substantial increase from the 17% of electricity demand renewable energy provided in 2010, and far greater than the country's goal of 35% of electricity demand in 2020. In terms of non-hydro renewables, that's an increase of 2.6 times today's levels.

Alternatively, the country could continue with its plans to scale renewable energy to 35%, and replace the remaining shortfall from nuclear power retirement with energy efficiency measures. Total electricity consumption would have to fall by 39 billion kWh between 2008 and 2010, an amount 3.3 times larger than amount electricity demand is already expected to decrease under the International Energy Agency's business-as-usual (BAU) projections for Germany. To make up for growing economic activity over this period, Germany would need to sustain a rate of improvement in electricity consumption per unit of economic activity (electricity/GDP) of 2.2% per year, up from the 1.47% annual improvement assumed by the IEA's BAU forecasts accounting for current German efficiency policies. As a further point of comparison, Germany's electricity consumption per unit of GDP fell by an average of about 1.7% annually from 1990 to 2010.

Nuclear or Fossil: Can Germany Shut Down Both?

However, none of these scenarios discussed in the previous section would result in any net reduction in carbon emissions, as each would simply see renewables and/or efficiency displace Germany's existing nuclear plants, a zero-carbon energy source, rather than coal or natural gas-fired power plants.

Thus, to achieve its stated goal of reducing emissions to 20% below 1990 levels by 2020 while also phasing out nuclear power, Germany would need to displace an additional 28 billion to 42 billion kWh of fossil-fuel fired generation from the electricity sector, above the nuclear power generation displaced by renewable energy in the scenario above.

If the country displaced entirely coal-fired generation, it would need to displace 28 billion kWh of electricity generation (about 5% of the country's 2008 electricity generation), while displacing an even mix of coal and natural-gas fired generation would amount to 42 billion kWh (8% of the country's 2008 electricity generation).

To both displace nuclear power and meet its C02 emissions reductions goals with renewable energy, Germany would have to scale the power supplied by renewable energy to at least 48 percent of total projected electricity demand in 2020, and as high as 50 percent if the country were to phase out an equal mix of natural gas and coal-fired generation. The electricity generated by non-hydro renewables would need to increase to 2.95 to 3.12 times today's levels.

Alternatively, the country could offset some of this generation using energy efficiency measures. To do so, the country would have to cut total electricity use by about 12% from 2008 electricity levels, a decrease of 67 billion kWh from 2008 to 2020. Here, energy efficiency programs would need to cut 2020 electricity demand by at least 5.7 times the BAU projected decrease in electricity, if it were replacing entirely coal-fired generation, while energy efficiency would need to cut 2020 electricity demand by at least 6.9 time the BAU projected decrease in electricity if it were replacing an equal mix of coal and nature gas. This would translate into an average annual decrease in the country's electricity consumption/GDP ratio of 2.79% in the case of replacing coal-fired generation, and 3.08% in the case of replacing an equal proportion of coal-fired and natural gas-fired generation.

Digging a Deeper Hole

Unfortunately, even as Germany contemplates simultaneously phasing out it's nuclear fleet and meeting ambitious goals for carbon reductions, the country is actually poised to dig itself an even deeper hole, as the country is in the process of building 10 coal-fired power plants, which would add 11,311 MW to the country's installed capacity. These plants would emit 69.4Mt of C02 annually, over a quarter of the Germany electricity sector's 2008 total carbon dioxide emissions, making it substantially more difficult for Germany to achieve each of the scenarios outlined above.

Germany has announced ambitious-sounding objectives on numerous fronts, from getting off of nuclear to leading the international climate charge. For now, however, the numbers and actions simply do not add up.

Photo by Minestrone.