Future thrills

Fuel cells are moving into our lives for real now.

There are said to be more than 2500 installations in the world, and all the car manufacturers are working on fuel cells. Apple Inc. is building a large datacenter using adaptions of fuel cells as part of the energy/power systems. There are projects in many parts of the world were fuel cells are being tried – NASA spaceships have had them, buses and cars, boats have them, data centers have them – the uses are many and the techniques used are many.

If we see them as an energy conversion device the theoretical efficiency is high – the energy to wheel ratio – up in the 80s or 90s percentages. The practical numbers are lower, but much higher – double or triple – that of petrol and diesel engines.

So what is the state of the art now?

Fuel cells were invented by Welshman William Grove in 1839,  but high cost and practical issues like heat transfer, high cost of materials, reliability have been hampering their spread.

There are many techniques: proton exchange membranes (PEMs), phosphoric acid fuel cells (PAFCs), molten carbonate fuel cells (MCFCs), solid oxide fuel cells (SOFCs).

It seems that solid oxide fuel cells (SOFCs) hold the greatest potential of any fuel cell technology. With low cost ceramic materials, and extremely high electrical efficiencies, SOFCs can deliver attractive economics without relying on CHP. But SOFCs operate at extremely high temperature (typically above 800°C), giving them extremely high electrical efficiencies and fuel flexibility, and creating engineering challenges.

The challenges are being solved now, and fuel cells are finally becoming clean, reliable, and most importantly, affordable.

• A fuel cell is like a battery that always runs. It has three parts: an electrolyte, an anode, a cathode. For a solid oxide fuel cell, the electrolyte is a solid ceramic material. The anode and cathode are made from special inks that coat the electrolyte. No precious metals, corrosive acids, or molten materials are required.
• An electrochemical reaction converts fuel and air into electricity without combustion. A solid oxide fuel cell is a high temperature fuel cell. At high temperature, warmed air enters the cathode side of the fuel cell and steam mixes with fuel to produce reformed fuel which enters on the anode side.
• So the chemical reaction begins in the fuel cell. As the fuel crosses the anode, it attracts oxygen ions from the cathode. The oxygen ions combine with the reformed fuel to produce electricity, water, and small amounts of carbon dioxide. The water gets recycled to produce the steam needed to reform the fuel. The process also generates the heat required by the fuel cell.
• As long as there’s fuel, air, and heat, the process continues producing clean, reliable, affordable energy.

The fuel used is most often hydrogen. The cost of producing hydrogen is still high.

To sum up, there are many uses for fuel cells

• Automakers, buses, boats, trains, planes, scooters, forklifts, even bicycles.
• Vending machines, vacuum cleaners and highway road signs.
• Miniature fuel cells for cellular phones, laptop computers and portable electronics
• Hospitals, credit card centers, police stations, banks
• Wastewater treatment plants and landfills are using fuel cells to convert the methane gas they produce into electricity.
• Telecommunications companies are installing fuel cells at cell phone, radio and 911 towers.
• Auxiliary power
• Supplemental power and backup assurance for critical areas, grid-independent generator for on-site service in areas that are inaccessible by power lines.

Fuel cells operate silently, they reduce noise pollution as well as air pollution and when the fuel cell is sited near the point of use, its waste heat can be captured for beneficial purposes.

Cogeneration building systems could reduce facility energy service costs by 20% – 40%.

So we are moving forward – it will be exciting to see promises fulfilled. Hardly any emissions, a bit of gas and a little water perhaps, quiet, reliable, efficient, cheap – we are not quite there yet but are moving forward.

This entry was posted on Monday, March 5th, 2012 at 1:13 pm and is filed under What humans do, What humans know. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.