Energy Quality and Shifts in Composition of Energy Input

Energy quality is the relative economic usefulness per heat equivalent unit of different fuels and electricity. One way of measuring energy quality is the marginal product of the fuel, which is the marginal increase in the quantity of a good or service produced by the use of one additional heat unit of fuel. These services also include services received directly from energy by consumers. Some fuels can be used for a larger number of activities and/or for more valuable activities. For example, coal cannot be used directly to power a computer whereas electricity can. The marginal product of a fuel is determined in part by a complex set of attributes unique to each fuel: physical scarcity, capacity to do useful work, energy density, cleanliness, amenability to storage, safety, flexibility of use, cost of conversion, and so on. But also the marginal product is not uniquely fixed by these attributes. (more…)

Gasoline Competition from Alternative Fuels

Most alternative fuel vehicles on the road today were originally designed for gasoline, but converted for use with an alternative fuel. Because the petroleum industry has successfully responded to the competitive threats of alternative fuels by developing reformulated gasoline that burn much cleaner, the conversions are typically performed more for economic reasons (when the alternative fuel is less expensive, which has occurred with propane) rather than environmental reasons. (more…)

Practicality and Reliability of Alternative Fuels and Vehicles

The demand for alternative fuels to substitute current fossil fuels is increasing more that ever. This is because the less availability of fossil fuel and the negative side effects to environment are the main issue that needs to be handled. Renewable energy such as wind, solar, tidal, hydro, geothermal or thermal are gaining more popular. The biomass energy industry in the production of respiration and dead organic matter can be used as industrial production or as fuel. (more…)

Miniature and Microscale Heat Engines for Power Generation Propulsion

Many characteristics of traditional engines make them attractive for use in power generation and propulsion technology. They tend to be self-aspirating and rely on combustion, which at the macroscale is a very robust form of heat generation. Fuel is plentiful and inexpensive, with storage easily realized. The energy density of the fuel (or fuel plus container), when compared with electrochemical sources, is high. Along with these advantages come a number of drawbacks, especially where miniaturization is concerned. For example, an engine is thermodynamically restricted (by the Carnot efficiency) in its conversion of chemical energy to work due to the intermediate heat-generating step. (more…)