The energy transition from fossil fuels to carbon-free sources will be a big challenge in the coming decades. In this context, the long-term prediction of energy demand plays a key role in planning energy infrastructures and in adopting economic and energy policies. In this article, we aimed to forecast energy demand for Spain, mainly employing econometrics techniques. From information obtained from institutional databases, energy demand was decomposed into many factors and economy-related activity sectors, obtaining a set of disaggregated sequences of time-dependent values. Using time-series techniques, a long-term prediction was then obtained for each component. Finally, every element was aggregated to obtain the final long-term energy demand forecast. For the year 2030, an energy demand equivalent to 82 million tons of oil was forecast. Due to improvements in energy efficiency in the post-crisis period, a decoupling of economy and energy demand was obtained, with a 30% decrease in energy intensity for the period 2005–2030. World future scenarios show a significant increase in energy demand due to human development of less developed economies. For Spain, our research concluded that energy demand will remain stable in the next decade, despite the foreseen 2% annual growth of the nation’s economy. Despite the enormous energy concentration and density of fossil fuels, it will not be affordable to use them to supply energy demand in the future. The consolidation of renewable energies and increasing energy efficiency is the only way to satisfy the planet’s energy needs.

A hybrid expert system called EXPLORE has been developed to manage the Seville City water-supply system. The main difficulties are the lack of information on management procedures, the complicated electrical tariff, the variability of the water network topology, and the dependency of the water demands, which is a major uncontrollable factor. EXPLORE reduces the cost of the operation of pumping the water to the different storage tanks. For this task EXPLORE employs the water demand forecast to obtain an optimal daily pumping schedule. EXPLORE has several additional benefits, in that it allows the collection of the operator's experience and the refinement of the operation processes through the simulation of new strategies, and it provides adequate training for new operators. The system has been applied to the management of the Seville City water-supply system. A prototype has been tested and has provided great improvement in the electrical costs (a savings of 25% over the current operation).

Mathematical equations governing kinetics of desorption from heterogeneous surfaces are derived from a master equation with the assumption that only nearest-neighbor adatoms interact. A number of cases are analyzed: random, periodical, and patchwise distributions of sites characterized by different activation energies. In general, the kinetic equations obtained must be solved numerically. We have performed numerical calculations for several specific cases and analyzed the influence exerted by heterogeneity and lateral interaction between adatoms on the desorption rate $\frac{d\ominus }{\mathrm{dT}}$. The results obtained make it clear that, due to lateral interaction, the desorption curves are very sensitive to the way in which heterogeneities are distributed on the surface (periodically, patches with different sizes, etc.).

The large amount of sensors in modern electrical networks poses a serious challenge in the data processing side. For many years, spectral analysis has been one of the most used approaches to extract physically meaningful information from a sea of data. Fourier Transform (FT) and Wavelet Transform (WT) are by far the most employed tools in this analysis. In this paper we explore the alternative use of Hilbert–Huang Transform (HHT) for electricity demand spectral representation. A sequence of hourly consumptions, spanning 40 months of electrical demand in Spain, has been used as dataset. First, by Empirical Mode Decomposition (EMD), the sequence has been time-represented as an ensemble of 13 Intrinsic Mode Functions (IMFs). Later on, by applying Hilbert Transform (HT) to every IMF, an HHT spectrum has been obtained. Results show smoother spectra with more defined shapes and an excellent frequency resolution. EMD also fosters a deeper analysis of abnormal electricity demand at different timescales. Additionally, EMD permits information compression, which becomes very significant for lossless sequence representation. A 35% reduction has been obtained for the electricity demand sequence. On the negative side, HHT demands more computer resources than conventional spectral analysis techniques.

By employing an extension of the Glauber–Ising model, the kinetics of the desorption of paired adatoms from a linear chain is studied. Three competitive mechanisms for changing a state of the system are allowed, namely desorption from or readsorption onto the chain or migration of the adatoms from site to site on the chain. The transition probabilities depend on an external field, on the interaction between nearest neighbors, and on three proper rate constants characterizing desorption, readsorption, and migration processes. An infinite set of coupled kinetic equations is obtained from the master equation. In order to compute the adsorption degree ϑ and the fraction of adjacent adatom pairs η, a ’’closure’’ approximation is taken. The steady‐state solution is in agreement with the exact result of the equilibrium statistical mechanics. We find that relaxation far from equilibrium is, in general, not describable by a single exponential. The relaxation is slower when mobility does not exist than when adatoms are mobile, though the system behavior is similar in both cases. Equilibrium state is reached most quickly when lateral interaction does not exist and the final adsorption degree is 0.5. Attractive lateral interaction yields relaxation slower than when interaction is null, while repulsive interaction favors an initial relaxation very quickly, and the system reaches an adsorption degree lower than the final one, passes through a minimum and tends to equilibrium state slowly.