Joel, As I remember Trace rebranded the (nominal 100 watt) OK4U units as MicroSine about 2000 AD. Didn't SMA (or someone else) recently take over the OK4U product line?
Do I understand you were not impressed with the MPPT OK4U microinverters performance (vs. the non-MPPT SMA?) under full sun? Do I understand correctly that you compared some 2,000 (OK4U?) microinverter units with 74 transformerless (?) SMA machines? The "as much as", "up to", etc. wording is why "caveat emptor" and "Your Mileage May Vary" should accompany each one of those comments. Kudos marketing mavens. Bill Loesch Solar 1 - Saint Louis Solar 314 631 1094 ----- Original Message ----- From: "Joel Davidson" <joel.david...@sbcglobal.net> To: "RE-wrenches" <re-wrenches@lists.re-wrenches.org> Sent: Wednesday, May 04, 2011 8:54 AM Subject: [RE-wrenches] Side-by-side microinverter, maximizer,and conventional inverter comparisons > Wrenches, > > A few years ago, we compared conventional and MPPT charge controllers and > found power production improvement in only in unique conditions and rarely > over 15%. Now Microinverter and DC maximizer companies are claiming "as much > as 25%" increased electricity production and a booming market. See > http://www.interpv.net/market/market_view.asp?idx=401&code=401&part_code=01 > > I've been comparing grid-connected microinverters since 1994 when Henk came > out with his OK4U and am not impressed in full-sun (no shade) comparisons. > In 2005, I compared a side-by-side 200 kW system with two 100 kW Xantrex > inverters with a 200 kW system with 74 SMA inverters and saw no difference > in kW or kWh. > > Have any wrenches made side-by-side comparisons? Are the claimed > improvements hype or real? > > Joel Davidson > > _______________________________________________ > List sponsored by Home Power magazine > > List Address: RE-wrenches@lists.re-wrenches.org > > Options & 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 > > _______________________________________________ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options & 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
