2.4.3. Drying cost and profitability From an economic viewpoint, the costs were evaluated from the data collected for the six dryers analyzed. The cost of daily energy consumption Cenrg (€/d) was a total of the cost of daily gas consumption plus electricity for each dryer start-up. This consumption was calculated according to the use period for the gas Δtg and for the fan Δtfan as shown in Eq. (11):