Hydrogen is colorless, odorless, tasteless and non-toxic. It is a gas at temperatures above -423° F and is highly diffuse, having a density approximately 14 times less than that of air. Because it is buoyant and diffusive, hydrogen dissipates quickly in open areas and can move through small spaces, which makes it difficult to store. Hydrogen is flammable over a broad range of gas concentration (from 4 to 74 percent), although its lower flammability limit – that is, the lowest temperature and pressure at which it will combust – is higher than those for some common fuels such as gasoline, propane or diesel.1 Hydrogen has been described as “the fuel of the future.” On Earth, hydrogen is found in combination with other elements such as carbon (hydrocarbons), oxygen (water) and nitrogen (ammonia). Although hydrogen may sometimes be used as a fuel, it is most often used as an energy carrier, such as electricity, and not an energy source. To make hydrogen a usable, stand-alone fuel, it must be separated from these other elements by chemical, thermal or electrochemical processes.

History British scientist Henry Cavendish identified hydrogen as a distinct element in 1766. Subsequent experiments by British and French scientists resulted in the first flight of a hydrogen balloon and the discovery that applying electricity to water can produce hydrogen and oxygen.

In the 1960s, NASA space capsules used hydrogen fuel cells for onboard electric power, heat and water.

  Fuel Cell Basics Through this website we are seeking historical materials relating to fuel cells. We have constructed the site to gather information from people already familiar with the technology–people such as inventors, researchers, manufacturers, electricians, and marketers. This Basics section presents a general overview of fuel cells for casual visitors. What is a fuel cell? How do fuel cells work? Why can’t I go out and buy a fuel cell? Different types of fuel cells.     What is a fuel cell? A fuel cell is a device that generates electricity by a chemical reaction. Every fuel cell has two electrodes, one positive and one negative, called, respectively, the anode and cathode. The reactions that produce electricity take place at the electrodes.

in general terms, hydrogen atoms enter a fuel cell at the anode where a chemical reaction strips them of their electrons. The hydrogen atoms are now “ionized,” and carry a positive electrical charge. The negatively charged electrons provide the current through wires to do work. If alternating current (AC) is needed, the DC output of the fuel cell must be routed through a conversion device called an inverter.

Oxygen enters the fuel cell at the cathode and, in some cell types (like the one illustrated above), it there combines with electrons returning from the electrical circuit and hydrogen ions that have traveled through the electrolyte from the anode. In other cell types the oxygen picks up electrons and then travels through the electrolyte to the anode, where it combines with hydrogen ions.

Price projections vary among fuel cell developers, but most are targeting costs below $1,500/kW

Maintenance costs of a fuel cell are expected to be comparable to that of a microturbine, ranging from $0.005-$0.010/kWh (based on an annual inspection visit to the unit).

At the current price, units are only used in high value, "niche" markets where reliability is premium, and in areas where electricity prices are very high and natural gas prices are low.

Solar energy, radiant light and heat from the sun

Figuring out an inexpensive and carbon-neutral way to produce an abundant amount of hydrogen will be key to the success of fuel cell vehicles

The sun delivers about 7000 times more energy than we currently consume globally. However, we cannot cover the whole surface of the Earth with solar energy collectors. How much of this energy can we collect? Will it be enough to replace fossil fuels?

Our global consumption of electricity in 2005 was 15,182 TWh/y (see The Little Green Handbook). However, 9,541 TWh/y of electricity was produced by fossil fuels and 2,555 TWh/y by nuclear power, or the total 12,096 TWh/y. Assuming the lowest solar potential and the lowest efficiency of solar cells we can calculate that we could produce 35 times more electricity than produced by fossil fuels and nuclear power. The additional advantage is that solar power is clean and last practically forever.

Even if we used only 1% of unused land area we could produce nearly 4 times more electricity than we produce using fossil fuels and nuclear power.

Coal generates 2,249 pounds of carbon dioxide, 13 pounds of sulfur dioxide and 6 pounds of nitrogen oxides for every megawatt hour of energy generated.

Biomass produces nitrogen oxides and small amounts of sulfur dioxide. The amount of carbon dioxide produced does not exceed that of the Earth's normal carbon cycle and is considered negligible.

"But if we could harness 0.1 percent of the energy in the ocean, we could support the energy needs of 15 billion people.

According to the government, geothermal has the potential to supply the United States with 20% of our electricity needs.

The capital cost of geothermal development is expensive, however; 2/3rds are drilling costs. Yet as we overcome some of these technology challenges and make the process more standardized it is believed that geothermal can supply up to 20% of the United States electricity needs by 2050. But innovation and investment in initial steps need to happen now.

Method Cents/kW-h Limitations and Externalities WindCurrently supplies approximately 1.4% of the global electricity demand. Wind is considered to be about 30% reliable. 4.0 - 6.0 Cents/kW-h Wind is currently the only cost-effective alternative energy method, but has a number of problems. Wind farms are highly subject to lightning strikes, have high mechanical fatigue failure, are limited in size by hub stress, do not function well, if at all, under conditions of heavy rain, icing conditions or very cold climates, and are noisy and cannot be insulated for sound reduction due to their size and subsequent loss of wind velocity and power. GeothermalCurrently supplies approximately 0.23% of the global electricity demand. Geothermal is considered 90-95% reliable. 4.5 - 30 Cents/kW-h New low temperature conversion of heat to electricity is likely to make geothermal substantially more plausible (more shallow drilling possible) and less expensive. Generally, the bigger the plant, the less the cost and cost also depends upon the depth to be drilled and the temperature at the depth. The higher the temperature, the lower the cost per kwh. Cost may also be affect by where the drilling is to take place as concerns distance from the grid and another factor may be the permeability of the rock. HydroCurrently supplies around 19.9% of the global electricity demand. Hydro is considered to be 60% reliable. 5.1 - 11.3 Cents/kW-h Hydro is currently the only source of renewable energy making substantive contributions to global energy demand. Hydro plants, however, can (obviously) only be built in a limited number of places, and can significantly damage aquatic ecosystems. SolarCurrently supplies approximately 0.8% of the global electricity demand. 15 - 30 Cents/kW-h Solar power has been expensive, but soon is expected to drop to as low as 3.5 cents/kW-h. Once the silicon shortage is remedied through alternative materials, a solar energy revolution is expected.

Tide 2 - 5 Cents/kW-h Blue Energy's tidal fence, engineered and ready for implementation, would provide a land bridge (road) while also generating electricity. Environmental impact is low. Tides are highly predictable.

Engineered geothermal systems (EGS) are based on a related principle, but they work even in parts of the world that are not volcanically active, by drilling thousands of metres underground to mimic the design of natural steam or hot-water reservoirs. Wells are bored and pathways are created inside hot rocks, into which cold water is injected. The water heats up as it circulates and is then brought back to the surface, where the heat is extracted to generate electricity. Because the Earth gets hotter the deeper you drill, EGS could expand the reach of geothermal power enormously and provide access to a virtually inexhaustible energy resource.