Good info on the string inverters, but I have to respectfully disagree on one small item:
mount the panels at the best slope/tilt to max the yearly output not to match the slope of the roof... I lost like 10% on that.
We did a study and the ideal angle here in Maryland is 40 degrees tilt. But we analyzed every other angle from 20 up to 50 and the annual total energy difference from 25 degrees to 50 degrees was only a 1% difference. Yes, the lower angle is worse output in the winter, but is better in the summer when the days are twice as long and so these things average out. Do not go below 15 degree angle or they don't get washed off in the rain and snow wont slide off. Anyone can prove this to themselves by using the PVWATTS on line calculator and just change the angle and see the total annual output change... not so much...
Thats why alomst all panels these days are just mounted right on the roof, no matter the angle. The structure to optimize the angle will cost more than the 1% gain.... Bob, WB4aPR
On Sat, May 5, 2018 at 10:47 PM, Mr B r a d via AMSAT-BB <amsat-bb@amsat.org
wrote:
good answers in this digest to FM voice sats frequencies ... perhaps someone could add to the wiki page ( the wiki was also a great idea :) regarding the RFI at '1/4mile either side of the I-271 & I-480/Hwy-422 intersection' perhaps worth noting that tiny transmittersin the tires of cars sometimes use uhf band to talk to the cars computer , monitoring the air in the tire... you would think wewould see problems from this RF hash on busy roads... Also many times our receivers go nuts due to out of band signals that only appear to be onthe ham channels but are not.... best check it with more than one type of radio ...( more than one range of 'I.F.' intermediate frequency chain in the receiver ) pics of the spectrum from a service monitor or SDR make the complaint more legit.good luck , I hear only about 36 outside employees at the FCC now that deregulation afflicts this countryand I think the NAB want them all working the tiny FM pirate broadcasters ... and with the two major radio station cluster ownersin bankruptcy are Iheart-radio and cumulus-media unfit to be license holders?? I think so ! regarding the solar power , I read the write up in qst ( tony-Brock Fishers April 2016 QST article "Can Home Solar Power and Amateur Radio Coexist?? )and used the good info on fair-rite cores and broadband AC line filters ( great ideas )http://valleymedia.org/satchat/k1kp-416-34-35.JPG but I disagree withthe information about using inverters on each panel ( who would want electronics on the hot roof ?) I would avoid the inverter panels ( should be banned ) , I dont want any switching power supply near my house..
When installing the 7kw system on my house. 7 companies come out and bid until i found a very local company who was willing to listen and work with me on the installand use the inverter brand recommended by the few hams i was able to get feedback from , this was a 'SunnyBoy' ( from Germany )we put the 7.1 kw inverter INSIDE the garage with a metal 'raceway 'box to hold the fair-rite cores ( type 31,43 and lots of cheap 75's ) http://valleymedia.org/satchat/choke-cores-ham-solor- house-_resized.jpg , a 100 amp broadband filter ( ebay $200 ) between the inverter output and the grid ,http://valleymedia.org/satchat/solar-inverter-rfi- choker-.jpg cores on all the meter and switch boxes.had them use real metal conduit for most of the runs...that was maybe a extra $300... this should be a rule of law..... one more tip local code required a DC disconnect switch be close to it , or if its to far ( like 15 feet ) from the meter box you have to use a remote DC disconnect switch.... http://valleymedia. org/satchat/sunnyboy-remote-dc-disconnect-.jpg more electronics on the roof ( more fair rite cores needed ) and went with two strings of DC ONLY solar panels 13 in each string ( had to stay below the 600v wire limit and put type-'75' cores all along the DC lines on the roof to break up the long 'return' wire run. ( directly under my 115ft wire Vee-beam ) I run 400w on HF and work all bands to 1296 , no noise from the inverterand no problems from my RF into the inverter .. ( cant say the same for the hot tub )some pics on my qrz.com page..one selling point on the sunny boy is a extra AC output you can get 1500 watts of power from the suneven if the power company grid is down.... its called the SPP outlet... so many of the install by ( the big guy ) solar city are very poor , under tree's and some on the north side of the roof... pick your contractor carefully and your parts even more so , another tip , mount the panels at the best slope/tilt to max the yearly output not to match the slope of the roof... I lost like 10% on that. can solar power work , heck yea... I have not got a real power bill since the install , system cost was ~ $3.40 a wattand I got a 30% tax credit this year from last years INVESTMENT in my home. a 100% refund of my FED tax for 2017.the power meter plays back and forth but never past the reading on the date of install...Ko6kL
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