Electricity generation is a demand-driven process. All the energy generated must be consumed at the same time. Consumption varies constantly and depends on several factors, such as weather and daylight. The same factors also affect renewable energy sources, such as wind and solar power, which limit the ability to make the most of these sources.

Humidity measurements in fuel cell applications are performed in a high humidity environment (typically over 80% relative humidity). It is difficult to take humidity measurements in near-condensing environments as condensation can saturate the humidity sensor. The sensor can take a long time to dry and recover.

During this time no measurements can be carried out and the humidity of the fuel flow cannot be checked. Vaisala's heated probes make it possible to avoid these problems as the relative humidity can be reduced to a level below condensation by heating the sensor element above the ambient temperature.