This strategy mitigates the installer’s O&M costs but it might not be the best solution for the customer, who paid for the modules and inverters to work consistently. Those failures could elevate their monthly utility bills into a higher tier.
While the argument for MLPE sounds reasonable on the surface, with benefits ranging from reducing the effects of partial shading and soiling to the cost-cutting, pre-emptive strikes achieved by using module-level monitoring for O&M and servicing, MLPE are not the best choice for all systems and applications and should be applied when conditions favor their usage.
MYTHS AND MISCONCEPTIONS
There are scientific, peer-reviewed resources that partly support the claims of MLPE companies, but when those claims are given proper scrutiny, many questions and concerns arise. Here are the top three myths concerning MLPE:
1. String inverters operate at the lowest performing module.
A common driver of this myth is the notion that if a module is shaded by 50 percent, then the rest of the string output power is reduced by 50 percent. Here is a common image used to illustrate this “Christmas tree effect”:
Optimzing PV Systems eFeature | July 2014
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