Phosphoric acid fuel cells (PAFCs) are more tolerant to impurities in hydrogen than PEMFCs or AFCs. PAFCs are typically used for stationary power generation but also to power large vehicles such as city buses. They are commercially available today, but their relatively high cost has restricted market uptake. Direct methanol fuel cells (DMFCs) are powered by methanol and are considered for a number of applications, particularly those based around replacing batteries in consumer applications such as mobile phones and laptop computers