Alternative Energy is a broad term for energy from non-conventional sources that is not renewable. Fuel cells, low-impact combustion engines, and hydrogen systems are often included in this category.
Block Diagram of a Hydrogen Fuel Cell System Generating Electricity from
Natural Gas or BioFuel.
A technology first widely used in space applications, there are numerous types of fuel cell, which produce electricity directly from a fuel. Hydrogen fuel is often used in conjunction with Fuel Cells, but a variety of fuels can be converted such as natural gas and biofuels (fuel cells converting a biofuel would be classified as a Renewable Energy generator). While fuel cells are currently expensive to manufacture, they have the advantage of silent operation with lower harmful emissions compared to combustion engines.
Recent advances in fuel cell design and materials science promise lower manufacturing costs, a wider range of fuels and higher efficiencies, making the fuel cell a viable option for numerous niche applications.
Under threat, the combustion engine technology is rapidly evolving. Engines today are more efficient, have fewer emissions, and can operate with a number of biofuels. There low-capital cost will continue to make them a preferred choice in many applications.
Hydrogen represents a promising means of storing and transmitting energy, and is often referred to as an “energy carrier” in the same way that electricity is. When converted through fuel cells or combustion engines, it finds use as a fuel. Hydrogen can be readily produced from Renewable Energy sources, and is envisioned as an economical means to consume excess wind or solar power instead of wasting (or shedding) it.
Storage of hydrogen is typically achieved either physically ― under high pressure or in extreme cold ― or chemically, in metal or complex hydrides.