Nick,
Is Enphase going to be introducing to market any time in the near-term a new micro with a higher output? It seems very likely that the trend toward higher output mods will continue. The M215 will surely be left behind to a greater degree as this trend continues if there are higher and reliable and comparably priced, on a dollar/watt basis, micros available. Thanks, marco Hi Carl, Marco, and Wrenches, As a longtime installer, I understand your point of view. Historically, I designed my string and microinverter systems with the same consideration for maintaining conservative DC to AC ratios. That being said, the costs of modules have decreased significantly and the dynamics have changed. Solar companies should be focused on selling systems that offers a great rate of return. Maximizing the customer's investment is most important. Isn't that what your customer wants? What Enphase is encouraging is the development of cost effective PV systems that will generate a healthy return. Considering that the modules are only 20% of the total system costs today, it is smart to give up 0.2% or more of the module production to lower the overall system costs by 5-10%. The NEC requires that the AC panel boards, conductors, and circuit breakers are sized to the inverter continuous output current rating. We should be maximizing this infrastructure. The data available indicates that when a system is installed with a 1.2 to 1.25 DC to AC ratio, it will rarely operate at peak output. Installing a PV system with a 1.25 DC to AC ratio is not driving the equipment to the maximum. In the case of the Enphase M215s; they are designed to operate continuously at peak output, so reaching that level a few hours in the first years is not problematic. To be clear, this limiting will occur the most during the spring months, because you have a combination of both cool weather and high irradiance levels. As Dan mentioned, this applies to string inverters as well as microinverters. One of the most common system designs of the early US grid-tied market was installing 18- 165 watt modules on an SWR-2500. I designed hundreds of projects like that. That was a ~1.2 multiplier, and was at a time when the modules cost $5 per watt; not $1 per watt. Why be more conservative now?
_______________________________________________ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
