Efficiency, sufficiency and consistency – these are the characteristics of sustainable energy supply. Renewable energy is perhaps the most important corner stone of this, because long-lasting, sustainable energy supply would not be possible without its contribution. A CO2-free energy cycle can only be achieved with renewable energy.
The production of energy from renewable resources, efficient energy use and energy saving measures go hand-in-hand. Switching to renewable energy means long-term supply security as it removes dependency on imported raw materials.
Moreover, renewable energy is clean: it does not require fuel, is emission-free, does not present any permanent safety risks when in operation and does not produce any radioactive waste for which there is no safe storage capacity.

The EEG specifies tariffs for the feed-in of energy produced from renewable sources. The feed-in tariff is a subsidisation measure which increases the share of renewable energy sources compared to conventional sources
Large utility companies often justify increases in the price of electricity with the excuse that high costs are incurred as a result of their duty to give precedence to feeding electricity generated from renewable energy sources into the grid. However, the share of the EEG in the total cost of energy is just four percent, with feed-in tariffs subject to constant degression. At the same time, large utility companies do not pass on the price-sinking effects of renewable energy on the cost of electricity to consumers.
Many consumers are not aware that for decades they have also been subsidising conventional energy production with tax money amounting to millions. Coal mining at German sites, for example, is, and always has been, financially supported by federal and state governments. The price of electricity from nuclear power plants, often considered the most cost-efficient and environmentally-friendly form of power, does not correspond to the actual costs incurred. If the operators of nuclear power plants were to be completely responsible for the costs and risks that come with using nuclear power, electricity would be considerably more expensive. The operators of nuclear power plants, as polluters, pay only a minor portion of the costs of transporting and temporarily storing radioactive waste.
External or subsequent costs are often not taken into consideration when comparing the costs of generating electricity: the damage to the environment and climate caused by burning fossil energy sources such as coal, oil and gas actually amounts to billions.

On a purely economic scale, solar power production costs are around 30 to 40 cents per kilowatt hour. The degression of feed-in tariffs means that this price is constantly falling. The costs incurred during energy production are made up of production costs, subventions and external costs. If all costs were reflected in the price of electricity, conventionally generated electricity would be significantly more expensive.

The amount of CO2 emitted per kilowatt hour (kWh) during electricity generation varies widely depending on the plant type. The exact amount of emissions cannot be precisely estimated so easily, because a number of parameters need to be considered, such as the energy used in extracting raw materials, transporting these raw materials to the power plant, constructing the power plant and disposing of waste and residue.
However, it is basically the case that using renewable energy to generate electricity creates the lowest CO2 emissions: CO2 is only emitted during plant manufacturing, but not when the plant is in operation. Plants that run on natural gas have average CO2 emissions and coal-fired power plants cause the largest amount of CO2. Although nuclear power plants emit a comparably small amount of CO2, they produce radioactive waste, which presents a huge risk to the environment and to our health: the half-life of plutonium-239 alone, one of the many components of radioactive waste, is around 24,000 years.

Environmentally friendliness is an important, although not the only, criterion for comparing energy sources. Important aspects such as operating safety, soil and nature conservation, water pollution control, other pollutant emissions and the waste disposal issue all form part of a complete ecological life cycle assessment. Moreover, cost-effectiveness, the prospect of long-term supply security, independence from imported raw materials and the social acceptability of energy production must also be taken into consideration.

A study published in 2008 carried out by the German Energy Agency (dena), which is part-financed by utility companies, predicts that as soon as 2012, power plant capacity will not be enough to cover the electricity requirements of the annual peak load, and that this deficit is set to increase considerably.
This conclusion contradicts numerous other studies and was officially refuted in the supply report provided by the then Federal Ministry for the Environment that same year.  The results of the dena study were examined by an independent expert consultancy. This reached the conclusion that many basic assumptions are unrealistic: the assumed energy requirements are too high and the energy efficiency potential too low, the availability of energy from renewable sources cited is too little and the average operating period of existing plants is too short.
In summary: the additional power plant capacity anticipated is safeguarded by the planned and approved construction of additional power plants. Moreover, sufficient reserve capacities are available, which ensure the security of electrical energy supply until 2020. Germany currently has excess capacities in energy supply and exports electricity.