Strategies for Increasing Electrical Energy Production from Intermittent Renewables

Renewable energy sources (RES) could play an important role in the sustainability of energy systems although at present their contribution is often marginal in countries' energy balances. Since the beginning of the twenty-first century, the European Union (EU) has officially recognized the need of promoting RES as a priority measure both for reduction of energetic dependence and for environmental protection and sustainable development. In recent years the share of renewable energy systems such as the Combined Heat and Power (CHP) and District Heating (DH) systems has increased permanently [EIA, 2009] due to important investment and promotion policies. Maintaining the balance between supply and demand in energy systems with large quantities of fluctuating renewable energy sources being utilized is a quite complex task. For this reason, the growing increase in penetration of RES must be joined with an optimization of whole energy systems to permit an effective energy saving, otherwise the great effort connected to promotion of those new energy systems will be not effective in order to provide a reduction in dependence on fossil fuel resources and in carbon emission to the atmosphere. In particular, it is shown how penetration of new renewable energies is limited at an upper level by technological considerations and will be more sustainable if an integration of various energy uses (thermal, mobility and electrical) field are considered. The chapter analyses some aspects in connection with the problem of new renewable energy penetration. The Italian scenario is considered as a meaningful reference due to characteristic size and complexity. The various energy scenarios are evaluated with the aid of multi-purpose software taking into account the interconnections between different energetic uses.