The fact of the matter is, regardless of the consumption method, a calorie is a calorie. The energy it takes to burn one liquid calorie equals exactly the same as that needed to burn one solid calorie. What throws some people off is the concept of caloric density. Foods that have high water content tend to have lower caloric density (think fruits and veggies), meaning a greater calorie to volume ratio. For example, to consume the same amount of calories you would get from one cup of raisins, you would need to eat nearly ten cups of grapes. What adds to this is that low caloric density foods tend to make you feel fuller faster because of their water content.
This does not mean that simply consuming more liquid will make you want to eat less. Liquid calories may in fact be deceiving because beverages like sodas often contain a lot of calories but do little to satiate hunger. When studies compared food intake between one group given water to drink and the other given soda, there was little difference in the amount of solid calories they ate. However, even though both groups ate roughly the same amount of food, the group who drank the soda consumed more calories overall because of the beverage that accompanied their meal.