The development of the electricity supply sector is characterised by a dynamically growing renewable energy market and an increasing share of renewable electricity. This will compensate for the phasing out of nuclear energy and reduce the number of fossil fuel-fired power plants required for grid stabilisation. By 2050, 88% of the electricity produced worldwide will come from renewable energy sources. ‘New’ renewables – mainly wind, solar thermal energy and PV – will contribute 75% of electricity generation. The following strategy paves the way for a future renewable energy supply:

• The phasing out of nuclear energy and rising electricity demand will be met initially by bringing into operation new highly efficient gas-fired combined-cycle power plants, plus an increasing capacity of wind turbines and biomass. In the long term, wind will be the most important single source of electricity generation.
• Solar energy, hydro and biomass will make substantial contributions to electricity generation. In particular, as nonfluctuating renewable energy sources, hydro and solar thermal, combined with efficient heat storage, are important elements in the overall generation mix.
• The installed capacity of renewable energy technologies will grow from the current 168 GW to 1,070 GW in 2050. Increasing renewable capacity by a factor of six within the next 42 years requires political support and well-designed policy instruments, however. There will be a considerable demand for investment in new production capacity over the next 20 years. As investment cycles in the power sector are long, decisions on restructuring the world’s energy supply system need to be taken now.

To achieve an economically attractive growth in renewable energy sources, a balanced and timely mobilisation of all technologies is of great importance. This mobilisation depends on technical potentials, cost reduction and technological maturity. Figure 4.8 shows the comparative evolution of the different renewable technologies over time. Up to 2020, hydro-power and wind will remain the main contributors to the growing market share. After 2020, the continuing growth of wind will be complemented by electricity from biomass, photovoltaic and solar thermal (CSP) energy.

None of these numbers describe a maximum feasibility, but a possible balanced approach. With the right policy development, the solar industry believes that a much further uptake could happen. This is particularly true for concentrated solar power (CSP) which could unfold to 30GW already by 2020 and more than 120GW in 2050. The photovoltaic industry believes in a possible electricity generation capacity of 350GW by 2020 in Europe alone, assuming the necessary policy changes.