ABSTRACT
Current energy systems are to a large extent based on fossil and nuclear fuels, and thus they are subject to rising long-term concerns over the associated emissions (greenhouse gases for combustion of fossil fuels and the risk of accidental releases of radioactive substances for nuclear reactors) and, in the medium term, issues of resource depletion. Alternatives without such problems include the renewable energy sources derived from the disposition of solar energy on the Earth. Several renewable energy sources are characterized by an intermittent flow, such as that of wind energy, which depends on passing weather systems, or that of solar radiation, which is absent at night and variable on cloudy days, in addition to the seasonal variation at higher latitudes. As regards energy systems, intermittency and variability should be seen in the light of energy production matching energy demand. The title of this book only mentions intermittency, but the book intends to deal with both intermittency and variability, which in many cases leads to intermittency if the variability causes inability to cover the demand at a given moment in time. The system may therefore be unable to follow changes in demand, even if the energy source flow is not intermittent. There are several ways of handling the issues posed by supply-demand mismatch, and these are the issues this book examines in detail.
