Tuesday, February 9, 2010


Fuel Cell Applications

A fuel cell is a device used to create electricity using Ultra Pure Hydrogen producing water and heat as byproducts. Due to the difficulty of storage and transportation of hydrogen the market demand has been shifted to adapt to natural gas as a fuel source. The down side of using fossil fuels is the CO2 byproduct, however compared to competing technologies (ie: traditional generators), fuel cells emit dramatically less green house gases. Fuel cells also have the advantage of having no moving parts in the fuel cell stack, so there is less maintenance required and greater reliability. Lastly, fuel cells are more efficient than traditional generators, meaning it costs remarkably less to make more electricity giving the user a quicker payback on initial investment. The best generators powered by internal combustion engines produce electricity with a staggering 20% peak efficiency. Fuel cells produce electricity at 60% efficiency which is 3 times more productive than the top of the line generator. When combining heat and power technology fuel cells can be up to 90% efficient.

Combined Heat and Power (CHP)

The most promising fuel cell technology for residential and small commercial applications is combined heat and power or CHP. A CHP Fuel Cell captures the heat that fuel cells create and uses it to heat your home, water, swimming pool, etc. So not only can you supply your electricity, you can also supply heat using the same piece of equipment. Residential fuel cells for CHP applications typically have electrical outputs of around 5kW and can produce enough heat to cover the demand of a large residence.


CHP Fuel Cells operate as long as there is a need for heat, so large homes in cooler climates are the most well-suited applications. Other prime candidates include homes with heated pools or hot tubs, where the heat generated can be used to heat the water. Fuel cells can also be used to make sure you always have power to critical electronics or refrigeration needs that you may have. This is of great concern in areas where grid power is unreliable and inconsistent.

How Do Fuel Cells Work?

In short there are three phases. In the first phase of a fuel cell Natural Gas is converted into an Ultra Pure Hydrogen with a carbon dioxide byproduct.
The second phase converts the hydrogen into usable energy. The hydrogen is split using a catalyst into protons and electrons. The hydrogen protons travel through the PEM membrane and join oxygen molecules on the other side to create water.
The electrons cannot travel through the membrane and are forced to travel around the membrane through an electric circuit. These electrons traveling through the circuit create DC electricity.
The final phase converts the DC electricity into a 110 AC power thru a process using an inverter. Inverters are also used in solar electric and wind applications.
Using a fuel cell that operates on natural gas will yield an electricity cost of about $.06 per kWh while power from the utility company costs about $.12 per kWh. The savings coupled with the Government tax credits help to offset the initial cost of purchasing a fuel cell.

They are proven in commercial applications, but what about residential?

In the United States fuel cells in the 1 to 10 kW range are an emerging market. Currently there are few options available to the general consumer, but rapid development is underway. It looks like the first fuel cells to become more widely available in the US are PEM fuel cells. PEM fuel cells operate on natural gas with electrical conversion efficiencies in the 30 to 40% range. Their total efficiencies with heat recovery can be up to about 90%. There seem to be three major companies that are leading the way in the US for residential fuel cells. Clear Edge and Plug Power both have fuel cells operating in the field, but availability seems to be limited.

http://www.clearedgepower.com/
http://www.bloomenergy.com/
http://www.plugpower.com/

Closely following the PEM cells will be solid oxide fuel cells. This type of cell has more fuel flexibility and can be configured to run on LPG (propane) as well as natural gas. SOFCs can have up to around 60% electrical conversion efficiency, but the total efficiency is still about 90% when used in a CHP configuration.

For updates on residential fuel cell applications stay tuned to the blog. If you have questions about fuel cells or other alternative energy solutions for your home or business don't hesitate to contact Energy-1.

No comments:

Post a Comment