<html><head></head><body name="Mail Message Editor"><div><span class="Apple-style-span">Jeff,<div><span class="Apple-style-span" style=""><br></span></div><div><span class="Apple-style-span" style="">I've installed a few SQ Flex. There is no need to use Grunfos panels. I generally shoot for a reasonably hi voltage, say 130 to 170 vdc when going array direct (at least for more rigorous pumping requirements). The pumps will work (and seems do do good ) at even lower voltage , 60 is a low as I go.<div><span class="Apple-style-span" style=""><br></span></div><div><span class="Apple-style-span" style="">For larger systems, in my case a 3hp 3phase, I am getting great results going hi voltage (say 400) array direct into an Aerovironment 3 phase inverter. The freq is wild, 30-60 hz depending on irradiance. This is primarily limited to standalone pumping sites where you do not already have significant inverter power. The Aerovironment comes in three sizes and they are in the AEE catalog. They are pricey but for high power loads they might be a solution. In my case , I use about 3200 w (stc) of array to drive a 3 hp pump.<div><span class="Apple-style-span" style=""><br></span></div><div>Don Loweburg</div></span></div></span></div></span></div><div class="aol_ad_footer" id="u3572363DA1A04550B4AB54A6D5C993D9"></div></body></html>