the years the fact remains that the devices will eventually either fail or wear out. The installer must balance these replacement costs (around $400 per truck roll), increased safety risks to personnel, equipment and module racking against the profit margins for the installation. For homeowners, the eventual wear out or premature device failures will introduce potential damage to the roof tiles or shingles, property damage and other nuisances. Advantages While microinverters generally have a lower efficiency than string inverters, the overall efficiency is increased due to the fact that every inverter / panel unit acts independently. In a string configuration, when a panel on a string is shaded, the output of the entire string of panels is reduced to the output of the lowest producing panel. This is not the case with micro inverters. A further advantage is found in the panel output quality. The rated output of any two panels in the same production run can vary by as much as 10% or more. This is mitigated with a microinverter configuration but not so in a string configuration. The result is maximum power harvesting from a microinverter array. Systems with microinverters also can be changed easier, when power demands grow, or decrease over time. As every solarpanel and microinverter is a small system of its own, it acts to a certain extent independent. This means that adding one or more panels will just provide more energy, as long as the fused electricity group in a house or building is not exceeding its limits. In contrary, with string based inverters, the inverter size need to be in accordance with the amount of panels or the amount of peak power. Choosing an oversized string-inverter is possible, when future extension is foreseen, but such a provision for an uncertain future increases the costs in any case. Monitoring and maintenance is also easier as many microinverter producers provide apps or websites to monitor the power output of their units. In many cases, these are proprietary; however this is not always the case. Following the demise of Enecsys, and the subsequent closure of their site; a number of private sites such as Enecsys-Monitoring sprung up to enable owners to continue to monitor their systems. Three-phase microinverters Efficient conversion of DC power to AC requires the inverter to store energy from the panel while the grid's AC voltage is near zero, and then release it