Journal of Fundamentals of Renewable Energy and Applications
Open Access

Energy Conversion

Energy conversion, transport & storage involve physical interaction or reaction at the surface / interface, therefore the nature of their surfaces, involving the precise area , surface energy, and surface chemistry, plays a very important role.

Energy transformations in mechanical or electrical form from fossil fuels involve an energy waste whose value, form a thermodynamic point of view, is strictly associated with temperature. Often, the quantitative dimension of this waste is bigger than the useful energy produced. Among the foremost energy wasteful sector, the transportation for people and goods may be a reference example: mechanical efficiency but 40 which there's already an honest value, being the most part of this range below 30 %. Thermal energy is wasted at medium temperature range (< 300 °C) and therefore the recovery (form one to 2 thirds of the input energy) is more a requirement than a concept and a huge interest is developing.

Moreover, many industrial thermal needs at medium and low power ranges produce energy streams discharged into atmosphere more or less in the least temperature levels (< 300-350 °C). Usually components or devices or energy integrated packaged systems require cooling, not associated with the thermodynamic cycles, and therefore the energy is wasted. Compressed air (CA) in industrial applications doesn't shake this waste phenomenon: an engineering rule of thumb states that nearly an equivalent amount of electricity absorbed is exchanged as waste heat into the lubricating oil and towards the environment by convection: temperature levels are low, 80-100 °C, and even the slightest recovery of this energy would be a significant contribution to the CA package efficiency. In fact, electricity for producing compressed gas within the industrial context represents a crucial share of the general electricity consumption: this figure accounts for 4-5 you look after global electrical consumption, and a saving of 5-10 you bored with terms of mechanical or electricity would end in an enormous contribution. Many sorts of renewable energy (geothermal, solar, etc…) behave as coldness energy sources could make use of innovative waste heat recovery solutions.