With today’s dry film technology, the voltage gradient can reach more than 250V/um for DC filtering applications. This means they are able to handle multiple voltage surges of up to twice the rated voltage, without significantly decreasing product lifetime. It also means the designer need only account for nominal voltage requirements when specifying his system. By comparison, for aluminium electrolytic capacitors, there is a trade-off:  the higher the voltage, the lower the available capacitance. In addition, at higher voltages, the electrolyte conductivity drops, which limits rms current values to about 50x less than film (20mA per µF, compared to 1A per µF for film capacitors). A major requirement for DC link capacitors is their ability to handle ripple current. Here film capacitors have a major advantage. Using aluminium electrolytics would require the use of several banks of capacitors, not because a higher capacitance value is required, but simply to handle the current. Using film capacitors would mean the designer need only consider the minimum capacitance value required. In wind applications, installation is often in remote places, and the trend in solar applications is to match the inverter to a single panel for its lifetime. Controlled self healing achieves this, and can equate to an order of magnitude lifetime over aluminum electrolytics depending on the application.