What is going to be the industry standard when replacing inverters?

[SolarPro]

A PV array is a current-limited source. An interactive inverter does not have a rotating mass and is controlled by power electronics that limit fault current characteristics. Extensive testing by NREL indicates:

"inverters designed to meet IEEE 1547 and UL 1741 produce fault currents anywhere between 2 to 5 times the rated current for 1 to 4.25ms."

That's probably not enough energy to open an OCPD. The utility grid is really the only source of fault current that matters in an interactive PV system. While I'm not an engineer, I have a hard time believing that the magnitude of these fault currents changes based on the topology of an inverter on the secondary side of the utility transformer.

Furthermore, all the test data I've seen shows that non-isolated inverters are inherently safer, by orders of magnitude, than transformer-isolated inverters in terms of detecting faults on the dc side of a PV system.

 

[Electric-Light]

It's disturbing that this is going the way of consumer appliances. There's an expectation of service parts to support the entire service life of a system.

 

[iwire]

It's disturbing that this is going the way of consumer appliances. There's an expectation of service parts to support the entire service life of a system.

Who would service the equipment?

Most electricians are not set up or trained for electronics troubleshooting so now you are stuck with a factory authorized technician at outrageous prices per hour.

 

[Electric-Light]

Who would service the equipment?

Most electricians are not set up or trained for electronics troubleshooting so now you are stuck with a factory authorized technician at outrageous prices per hour.

Service components or modules should be available just like we have breakers, receptacles that would not be legal under code now available for replacement use only. Or you know, they send you a rebuilt unit, credit you the return credit once the old is received back by them.

 

[ggunn]

Who would service the equipment?

Most electricians are not set up or trained for electronics troubleshooting so now you are stuck with a factory authorized technician at outrageous prices per hour.

Just like anything else, at some point it becomes more expensive to fix than to replace.

 

[SolarPro]

The sky isn't falling. Replacement parts for PV systems are both higher performing, have more features and cost considerably less than the legacy equipment. Inverter replacement is usually as simple as "out with the old and in with the new" and the new products are more efficient and have improved safety features as compared to the equipment they replace. In tricky situations, you can use module-level power electronics to provide granular design flexibility. Also, PV modules are finally being produced at the kind of scale where we are starting to see the standardization, in terms of physical sizes and electrical performance characteristics, that comes with commoditization.

That's really the biggest difference between the solar products and things like breakers, sheets of plywood or USB dongles. The rapid growth of the industry works against attempts at standardization. Companies like having their proprietary features, even though consumers and O&M providers would benefit from backwards compatibility and cross-platform compatibility. Until investors or AHJs start demanding that kind of standardization, it's unlikely to happen voluntarily. This isn't unique to the solar industry, but is probably true of any emerging technology early in its adoption cycle.