alternative energy

Examples of alternative energy in the following topics:

• New Energy Sources

  • Alternative and renewable energy sources can reduce the environmental impact of energy production and consumption.
  • Renewable energy is energy that comes from natural resources, such as sunlight, wind, rain, tides, waves, and geothermal heat, which are all naturally replenished.
  • While many renewable energy projects are large-scale, renewable technologies can also be suited to rural and remote areas, where energy is often crucial in human development.
  • Ethanol is a quasi-renewable energy source.
  • This is because, while the energy is partially generated by non-depletable sunlight, the harvesting process requires vast amounts of energy that typically comes from non-renewable sources.

• Energy Consumption

  • The environmental impact of the energy industry is diverse.
  • Energy has been harnessed by humans for millennia.
  • However, if we explore viable alternative energy resources, we could reduce our impact on the environment.
  • A wind turbine is a device that converts the natural kinetic energy from the wind into electrical power.
  • Wind turbines provide a green source of alternative energy, as opposed to the burning of fossil fuels which contributes to climate change.

• Lattice Energy

  • Lattice energy is a measure of the bond strength in an ionic compound.
  • As an example, the lattice energy of sodium chloride, NaCl, is the energy released when gaseous Na+ and Cl- ions come together to form a lattice of alternating ions in the NaCl crystal.
  • Alternatively, lattice energy can be thought of as the energy required to separate a mole of an ionic solid into the gaseous form of its ions (that is, the reverse of the reaction shown above).
  • Sodium ions (Na+) and chloride(Cl-) ions, depicted in purple and green respectively, alternate in the crystal lattice of solid NaCl.
  • This tutorial covers lattice energy and how to compare the relative lattice energies of different ionic compounds.

• Bond Energy

  • Bond energy is the measure of bond strength.
  • Alternatively, it can be thought of as a measure of the stability gained when two atoms bond to each other, as opposed to their free or unbound states.
  • These energy values (493 and 424 kJ/mol) required to break successive O-H bonds in the water molecule are called 'bond dissociation energies,' and they are different from the bond energy.
  • The bond energy is the average of the bond dissociation energies in a molecule.
  • The bond energy is energy that must be added from the minimum of the 'potential energy well' to the point of zero energy, which represents the two atoms being infinitely far apart, or, practically speaking, not bonded to each other.

• Hydration of Alkynes and Tautomerism

  • The first is the potential energy difference between the tautomeric isomers.
  • The second factor is the activation energy for the interconversion of one tautomer to the other.
  • Since the potential energy or stability of a compound is in large part a function of its covalent bond energies, we can estimate the relative energy of keto and enol tautomers by considering the bonds that are changed in the rearrangement.
  • The potential energy change for this rearrangement is even more advantageous than for enol-keto tautomerism, being estimated at over 25 kcal/mole from bond energy changes.
  • The controlling difference in this case must be a prohibitively high activation energy for the described rearrangement, combined with lower energy alternative reaction paths.

• The Hydrogen Economy

  • As such, hydrogen is not a primary energy source, but an energy carrier.
  • Hydrogen production is mostly accomplished by steam reforming from hydrocarbons, but alternative methods are being developed.
  • Fuel cells require less energy input than other alternatives and perform water electrolysis at lower temperatures, both of which have the potential of reducing the overall cost of hydrogen production.
  • Although H2 has high energy density based on mass, it has very low energy density based on volume.
  • Alternatively, liquid hydrogen or slush hydrogen (a combination of liquid and solid hydrogen) can be used.

• Mechanistic Background

  • Both the ground (lowest energy electronic state) and excited states are shown as energy profiles populated by vibrational energy states (green lines) as well as rotational states (not shown).
  • Such states have a single energy state in an applied magnetic field, and are called singlets.
  • In a magnetic field such states have three energy levels (+1, 0, -1) and are called triplets.
  • Internal conversion of excited states to lower energy states of the same multiplicity takes place rapidly with loss of heat energy (relaxation).
  • Alternatively, an excited state may return to the ground state by emitting a photon (radiative decay).

• Fuel Cells

  • Fuel cells are a compelling alternative to batteries, but they are still in the early stages of development.
  • The development of miniature fuel cells can provide a cheap, efficient, and reusable alternative to batteries.
  • First of all, since the energy used to produce the hydrogen is comparable to the energy in the hydrogen, it is inefficient, and therefore expensive.
  • If the electricity produced by clean, renewable energy sources, such as solar and wind power, is used to produce hydrogen, the energy can be stored more easily than in large battery complexes.
  • Fuel cells are a potential energy source for cars that do not run on gasoline.

• Microstates and Entropy

  • Energy can be shared between microstates of a system.
  • It determines that thermal energy always flows spontaneously from regions of higher temperature to regions of lower temperature, in the form of heat.
  • This is the basis of an alternative (and more fundamental) definition of entropy:
  • In terms of energy, when a solid becomes a liquid or a liquid a vapor, kinetic energy from the surroundings is changed to ‘potential energy‘ in the substance (phase change energy).
  • Phase-change energy increases the entropy of a substance or system because it is energy that must be spread out in the system from the surroundings so that the substance can exist as a liquid or vapor at a temperature above its melting or boiling point.

• Nuclear Reactors

  • The energy released from nuclear fission can be harnessed to make electricity with a nuclear reactor.
  • The amount of free energy in nuclear fuels is far greater than the energy in a similar amount of other fuels such as gasoline.
  • In many countries, nuclear power is seen as an environmentally friendly alternative to fossil fuels, which are non-renewable and release large amounts of greenhouse gases.
  • A neutron moderator works to reduce a newly produced neutron's kinetic energy from several MeV to thermal energies of less than one eV, making them more likely to induce further fission.
  • Just as many conventional thermal power stations generate electricity by harnessing the thermal energy released from burning fossil fuels, nuclear power plants convert the energy released from nuclear fission.