Editing Fuel cell (section)

===Portable power systems===
Portable fuel cell systems are generally classified as weighing under 10&nbsp;kg and providing power of less than 5&nbsp;kW.<ref name="sciencedirect.com">{{cite journal|last1=Agnolucci|first1=Paolo|title=Economics and market prospects of portable fuel cells|journal=International Journal of Hydrogen Energy|date=December 2007|volume=32|issue=17|pages=4319–4328|doi=10.1016/j.ijhydene.2007.03.042|bibcode=2007IJHE...32.4319A |s2cid=98471675 }}</ref> The potential market size for smaller fuel cells is quite large with an up to 40% per annum potential growth rate and a market size of around $10 billion, leading a great deal of research to be devoted to the development of portable power cells.<ref name="ReferenceA">{{cite journal|last1=Dyer|first1=C.K>|title=Fuel cells for portable applications|journal=Journal of Power Sources|date=April 2002|volume=106|issue=1–2|pages=31–34|bibcode=2002JPS...106...31D|doi=10.1016/S0378-7753(01)01069-2}}</ref> Within this market two groups have been identified. The first is the microfuel cell market, in the 1-50 W range for power smaller electronic devices. The second is the 1-5&nbsp;kW range of generators for larger scale power generation (e.g. military outposts, remote oil fields).

Microfuel cells are primarily aimed at penetrating the market for phones and laptops. This can be primarily attributed to the advantageous [[energy density]] provided by fuel cells over a lithium-ion battery, for the entire system. For a battery, this system includes the charger as well as the battery itself. For the fuel cell this system would include the cell, the necessary fuel and peripheral attachments. Taking the full system into consideration, fuel cells have been shown to provide 530&nbsp;Wh/kg compared to 44&nbsp;Wh/kg for lithium-ion batteries.<ref name="ReferenceA"/> However, while the weight of fuel cell systems offer a distinct advantage the current costs are not in their favor. while a battery system will generally cost around $1.20 per Wh, fuel cell systems cost around $5 per Wh, putting them at a significant disadvantage.<ref name="ReferenceA"/>

As power demands for cell phones increase, fuel cells could become much more attractive options for larger power generation. The demand for longer on time on phones and computers is something often demanded by consumers so fuel cells could start to make strides into laptop and cell phone markets. The price will continue to go down as developments in fuel cells continues to accelerate. Current strategies for improving micro fuel cells is through the use of [[carbon nanotube]]s. It was shown by Girishkumar et al. that depositing nanotubes on electrode surfaces allows for substantially greater surface area increasing the oxygen reduction rate.<ref>{{cite journal|last1=Girishkumar|first1=G.|last2=Vinodgopal|first2=K.|last3=Kamat|first3=Prashant|title=Carbon Nanostructures in Portable Fuel Cells: Single-Walled Carbon Nanotube Electrodes for Methanol Oxidation and Oxygen Reduction|journal=J. Phys. Chem.|date=2004|volume=108|issue=52|pages=19960–19966|doi=10.1021/jp046872v|url=https://figshare.com/articles/journal_contribution/27622419 }}</ref>

Fuel cells for use in larger scale operations also show much promise. Portable power systems that use fuel cells can be used in the leisure sector (i.e. RVs, cabins, marine), the industrial sector (i.e. power for remote locations including gas/oil wellsites, communication towers, security, weather stations), and in the military sector. SFC Energy is a German manufacturer of [[direct methanol fuel cell]]s for a variety of portable power systems.<ref>{{Cite web|url=https://www.sfc.com/en/|title=SFC Energy AG - Clean energy everywhere|website=SFC Energy}}</ref> Ensol Systems Inc. is an integrator of portable power systems, using the SFC Energy DMFC.<ref>{{Cite web|url=https://www.ensolsystems.com/|title=ensol systems|first=ensol|last=systems|website=Ensol Systems}}</ref> The key advantage of fuel cells in this market is the great power generation per weight. While fuel cells can be expensive, for remote locations that require dependable energy fuel cells hold great power. For a 72-h excursion the comparison in weight is substantial, with a fuel cell only weighing 15 pounds compared to 29 pounds of batteries needed for the same energy.<ref name="sciencedirect.com"/>