World is depending on fossil fuels like coal and oil for Energy. Incomplete combustion of coal and oil produces particulate matter. Heavier particulates produce an annoying dirty grit, and lighter particulates can be inhaled deeply and become a health hazard. In addition to the desired combustion of organic molecules, impurities such as sulfur also burn and produce potentially dangerous oxides. Since the air is made of 80% nitrogen, nitrogen is combusted along with the fuel at high temperatures, releasing nitrous oxides. Since fossil fuels are composed mainly of carbon by weight, all fossil fuels produce carbon dioxide when burned. In the atmosphere, the sulfur and nitrous oxides produce sulfuric acid and nitric acid, respectively, which can lead to acid rain.

To avoid such effects, it is the time to choose an alternative system to produce energy with zero pollution. Solar energy technology makes the path for such alternative system. The growth of solar energy technology is appreciable for the past 2 decades. Its applications range widely which makes a special interest in implementing solar energy system everywhere. The renewable form of input which is the sun light is available in free of cost. The efficiency of solar system is comparatively higher than any other energy producing devices and also free of pollution.

The goal of this special issue is to bring out new ideas related to solar energy technology which may help the researchers and scientists to implement such ideas in our day today activities. This special issue of Energy and Power invites authors to submit their research works which may cover any of the following topics.

PV generation system is one of the most popular uses of direct solar energy and its installation is rapidly growing because it is considered as a clean and environmentally-friendly source of energy. The technology employed in PV systems is quite well-developed with improvements and modifications made regularly, particularly in energy conversion processes. The systems are quite reliable and have been well tested in space and terrestrial applications The primary obstacle to increased use of PV systems is their high initial cost. However, in some remote off-grid locations, as short as one quarter mile, PV systems can be cost effective as compared to the cost of running power lines into the property and the subsequent continual electric charges. Presently, some utilities have established PV centralized generating stations as a form of green power option which allows customers to pay a small fee on their monthly utility bill for the construction of additional PV installations.

PV systems are constructed either in standalone, grid connected or hybrid configurations. The standalone and hybrid PV generation systems are attractive as indispensable electricity source for remote areas. On the other hand, the PV grid connected systems can be used as distribution generation units in an electrical power system. The PV generation system installation can be configured in the form of either centralized or distributed systems. The centralized PV systems are usual located at the load center and supply power to all consumers while the distributed PV systems supply power to consumers individually. The advantage of the centralized PV generating system is that its size may be smaller than the distributed system since the diversity factor is taken into consideration. As for the commercial PV generation systems, it can be classified based on its power rating and application. The power ratings of the existing PV systems are typically 0.5 to 20 kW, and it supplies power to various loads such as residential loads, pumping loads, lighting loads and small mobile communication transceivers. The use of PV systems is attractive for water pumping applications in rural areas of many developing countries. As for residential application, PV generation systems are very feasible for supplying power to rural sites where the connection to the grid is very difficult and costly.

The major problem of PV system installation is the high capital cost compared with conventional energy sources. Currently, many research works are carried out focusing on optimization of PV systems in order to reduce the capital cost of the PV system without affecting its reliability. The optimization of a PV system means that the system parameters such as number of PV modules, capacity of storage battery, capacity of inverter and PV array tilt angle must be selected optimally. In addition, diesel generator and wind turbine capacities must be optimized in case of hybrid PV systems. Moreover developing some electronic features that maximize the yield of these systems such as sun trackers, MPPT and smart inverters. PV system size and performance strongly depend on metrological variables such as solar energy, ambient temperature and wind speed. Therefore, to optimize a PV system, extensive studies related to prediction of metrological variables have to be done using accurate models of these systems.

The last 20 years has seen some interesting developments in applied thermodynamics in improving the efficiency of thermal cycles. This is particularly important in hot climates where the increased ambient temperature has a negative influence on the thermal efficiency of generation equipment such as gas turbines. To overcome this ingenious arrangements of combined cycles have been proposed to make use of the waste heat from the initial cycle to improve its efficiency (entropy generation minimization) but also when power is not required to produce fresh water from desalination plants or to feed pottery kilns or LNG gasification plants (to name but a few). Also new thermodynamic cycles, such as the COOLCEP-S, Kalina, MATIANT, Brayson, Goswami have been proposed. Several ORC based systems using solar power combined with geothermal energy have been analysed and suitable working fluids identified. This special edition is intended to focus on new developments in combined thermal systems for improved thermal efficiency and minimal environmental impact.

Improved energy efficiency is one of society’s most important instruments for mitigating climate change. Road transport is responsible for a large part of energy consumption worldwide. Nowadays, road transportation is almost entirely dependent on crude oil (about 95%). Therefore, in order to meet global GHG emission mitigation targets, as well as to decrease oil dependency, overall energy consumption of road vehicles must be reduced significantly. The major challenge in reaching this goal is that the necessary reductions in carbon emissions by vehicles must be achieved without any disruptions in transportation patterns and population mobility. According to experts analysis, above 80% of the projected GHG emissions mitigation may be achieved by improvement of vehicle efficiency, introduction of alternative fuels and electricity decarbonization. This special issue of Energy and Power is focused on advanced vehicle propulsion technologies, alternative low carbon intensity fuels and vehicle performance while using these fuels, ways and methods of ensuring an effective energy use by road transportation.

The goal of this special issue is to provide a technological and scientific endeavor for experts all over the globe to promote, share and discuss challenging new issues and developments in various areas of vehicle propulsion technologies, effective energy use by road transport, automotive implementation and performance of alternative low carbon intensity fuels.

This special issue of Energy and Power invites authors to submit original and unpublished research works in the mentioned and other fields related to energy efficiency of road vehicles and GHG emissions mitigation. Original research, review and case study articles can be submitted.