EFOY fuel cells are typically paired with solar arrays that offset the amount that the fuel cell needs to run. In a well-balanced system, the solar array is sized to power the load during the summer months and into the shoulder seasons, and the fuel cell ramps up to cover the load in the winter months. We usually aim for a balance where the EFOY runs about 1500-2000 hours per year giving the fuel cell a maintenance interval of approximately 2.5-3 years (5000 hours). At the outset of each project Ensol conducts a Power Analysis to size the system and estimate fuel consumption and maintenance intervals.