Sustainable Energy Systems: Optimization and Efficiency

Abstract

The world population is growing at a very high rate, which also entails a massive increase in energy consumption, and also, therefore, in its production, which is gradually and steadily increasing. Energy and the environment are essential to achieving sustainable development, and constitute a fundamental part of human activity. If we consider energy efficiency as the use of an appliance, process or installation for which we try to produce more energy, but with less energy consumption than the average for these appliances, processes or installations, then achieving a higher energy efficiency is imperative. Energy efficiency is a cornerstone policy on the road to stopping climate change and to achieving sustainable societies, along with the development of renewable energy and an environmentally friendly transport policy. In this Special Issue, 11 selected and peer-reviewed articles have been contributed, on a wide range of topics under the umbrella of sustainable energy systems. The published articles encompass distinct areas of interest. One area addresses distributed generation, which addresses such topics as the optimal planning of distributed generation, protection of blind areas in distribution networks, multi-objective optimization in distributed generation, energy management of virtual power plants in distributed generation, and the impact of demand-response programs on a home microgrid, as well as concentrating solar power into a highly renewable, penetrated power system. The second section of the Special Issue addresses a wide range of topics, from parametric studies of 2 MW gas engines or data centers, to combustion characteristics of a non-premixed oxy-flame, to new techniques of PV Tracking, to applications of nanofluids in the thermal performance enhancement of parabolic trough solar collectors.

Integrated Geothermal Energy Systems for Small-Scale Combined Heat and Power Production: Energy and Economic Investigation

“…The main components of an ORC are a pump, an evaporator, a turbine, and a condenser (Figure 2a) [85,86]. The pump increases the pressure of the organic working fluid to the maximum value (1-2 process) then the evaporator is adopted to obtain the superheated vapour (2-3) that expands in the turbine (3)(4) to provide the mechanical work that is converted into electricity by an alternator. Finally, the working fluid is condensed (4-1).…”

“…The behaviour of the geothermal organic Rankine cycle system at full and part loads has been defined in terms of electric power and efficiency. The electric power Pel is evaluated as: (4) where Pt and Pp represent the ORC turbine and pump power, respectively, while ηem,t and ηem,p are the corresponding electro-mechanical efficiencies. Pp,g and Pp,cool denote the power request of the pumps used to drive the geofluid and the cooling water, whereas ηem,g and ηem,cool are the corresponding electro-mechanical efficiencies.…”

“…Combined heat and power (CHP) generation presents several advantages in terms of lower costs, emissions, fuel consumption, and higher decentralised generation share as compared to conventional separate electric and thermal production [1][2][3]. During the last few years, the research community and the industry have been focusing increased attention on renewable sources, sustainability and global efficiency [4][5][6]. In this framework, geothermal energy represents an interesting resource and, due to its not intermittent availability, an attractive solution for lowering fossil-fuel dependence and their environmental impact [7][8][9].…”

Numerical Modeling, Simulation and Evaluation of Conventional and Hybrid Photovoltaic Modules Interconnection Configurations under Partial Shading Conditions

“…In recent years, renewable energy resources (RERs) have gained a peculiar interest to procure cost-effective energy production. RERs have been deployed significantly at a wider scale by several nations to offset electricity generation prices taking into account the fact of ever-increasing energy demand [1][2][3][4][5]. Among RERs, solar generation has gained special attention and remarkable research is headway in the photovoltaic(PV) area [6,7].…”