Long-term scenarios and strategies for the deployment of
renewable energies in Germany in view of European and
global developments
Page 11
"By 2020 already, the installed capacity of renewables at 117 GW, is considerable greater
than the expected maximum grid load of about 80 GW. With 97 GW capacity, the share of the
fluctuating sources of energy wind and solar radiation dominates (Table 2). At that point in time,
the photovoltaic capacity exceeds the entire installed capacity of wind power, but only
generates 40% of the amount of electricity of wind power. The high installed capacity of
fluctuating renewable sources demonstrates the sharply growing need for balancing and
storage options by 2020 at the latest. For this reason, growth of international grid connection
and of “domestic” off-shore wind power is emphasized in the scenario after 2030, while the
growth of domestic PV capacity slackens off in the long term. The installed capacity of
renewables grows to a total of 179 GW, if the proportional capacity of imports of energy from
renewables is taken into account. In Scenario 2011 A, about 40 GW of this (110 TWh/yr) is
intended for the provision of hydrogen from renewables as a storage medium and as a fuel,
which is consumed by electrolysers according to the supply of power from renewables.
Because of the considerable expansion of renewables, the utilization of fossil-fuel power
stations drops from an average of 4600 hours per year in 2010 to 3700 h/yr in 2020; after that,
the decline becomes even greater (2030: ca. 3300 h/yr: 2050: ca. 2200 h/yr). "
Refer Figure 15 mini-CHP to provide 5GW by 2030.
"The merit order in Figure 15 illustrates the importance of CHP among power stations. The
expansion of CHP offers great potentials for efficiency, but should be promoted speedily by
2020, in order to avoid a conflict between the goals of the Energy Concept for expansion of
renewables, for rehabilitation of the building stock, and for cogeneration. In the long term, it is
foreseeable that, on the one hand, the heat demand for heating will decline, and on the other,
the shares of fluctuating renewables will continue to increase. Both factors will make the
utilization factor, and thus the profitability, of CHP drop considerably. Therefore, it appears necessary to complete the expansion of CHP by 2020, and to flexibilize it by means of heat
storage systems, so that the investments are worthwhile and the energy goals are achieved.
Load management can also make a substantial contribution to this. For 2020, a large potential
is seen in controlling the existing off-peak storage heaters and electric warm-water storage
tanks for tap water. Although these installations should no longer play any role in the heat
market in the long term from the environmental point of view, until then, they can make a
contribution to integration of the renewables by appropriate control systems. In one or two
decades, the potential for load distribution of electromobility, electric heaters, geothermal heat
pumps, household appliances, and air conditioning for the benefit of integration of renewables
will also develop, showing clearly the advantage of the interaction between the energy sectors
electricity, heat, and transportation, and of the overlapping use of energy storage systems (heat
storage systems, batteries). "