Solar question/s

The master plan · 08-19-13, 05:35 AM

Looking over the posts and such...guessing from my location and partial shading at times in summer and leaving branches in winter to somewhat shade....

I am thinking the mini inverters would be best for a new install. Does it matter than if the panel themselves have the bypass diodes then? Some solar panel sellers here haven't even heard of a panel with bypass diodes or know what it is.

This would be for a later date install, if I can justify the costs vs payback and capability. If you are following the my other posts I am thinking about my garage roof. 270sq feet of really good in summer and 240 sq feet of somewhat good(lower level of roof) The upper would receive nearly shade free all year, at least until my neighbors tree grows taller, unless the ash borer gets it first. Other concern is weight on roof.

Also with the mini inverters what else is needed to net meter? There is a new digital meter on the house now. I want a grid tie system and would convert to off grid if possible at a later date when I can generate enough power myself. This would have to include 220v also. I can use as much as 600kw to as low as 260kw a month.

Crazy me lives in town also, but I am close to disconnecting from the city heat (no gas line to house, its hot water from coal plant) and want to start a plan for electric also.

There seems to a trend developing of charging more for the meter/access to power than the consumption of it. Several gas suppliers have said a drop in assuage has forced them to charge more for a meter. My own city has said the water meter will cost more because of the same. Its a steady line of cash and can never go down with green power or conservation.

On the plus side we have two 2MW wind turbines in town also. But they might as well outlaw home turbines with their max height ordnance.

pinballlooking · 08-19-13, 09:04 AM

You need to look at Gary’s and Doug’s projects.
http://www.builditsolar.com/Projects...asePV/Main.htm Designing and Installing a Grid-Tie PV System
and Doug
http://www.builditsolar.com/Projects...ougEnphase.htm
They did a great job of documenting micro inverters and the process.

Xringer · 08-19-13, 09:26 AM

EnPhase publishes a list of compatible panels for each of their inverter models.

pinballlooking · 08-19-13, 09:31 AM

here is the list for the M-215 micro inverter by Enphase.
http://enphase.com/wp-uploads/enphas...ility_List.pdf

where2 · 08-19-13, 10:50 PM

Avoid the solar panel sellers who don't know what bypass diodes are. There are plenty of reputable places selling panels ridiculously cheap. If going grid tie, you want a UL listed panel. That M-215 list is a good place to start.

As for weight on the roof, a 220W-235W 60 cell panel is roughly 3'x5' and weighs ~45lbs. That's 3lbs per square foot (in the horizontal plane, roughly 7lbs at a 45°). As you will note, the load increases when you consider the tilt involved, but it's not as if it is 50lbs per square foot. Don't forget to look at snow load though. (In FL, I ignore show load.)

As for "new digital meter" vs. "net meter": the GE i210+ Smart Meters come programmed from GE to accumulate forward whether they are reading "Received" or "Delivered" (like a car odometer, they don't go backward). If you don't tell the POCO, and you back feed an ordinary GE i210+ without telling them, you end up paying the POCO for the pleasure of giving them free power. My utility brought me out a completely different brand "Landis + Gyr" as a bi-directional meter, and took away my GE i210+.

If you think "base billing fees" are expensive, you haven't priced self-generation. A set of batteries for autonomous generation makes my $7/mo base billing fee look like a bargain.

My $56/mo water + sewer bill looks expensive, until I listen to my friends with wells talk about softener salt, bottled water and all the other things they deal with to use what they pump out of the ground, and drop into their septic systems. Then my $56 actually looks cheaper than the alternative.

Robaroni · 08-21-13, 06:28 PM

I agree about the diodes, someone doesn't know don't buy from them.

I have a roof system with microinverters (SolarEdge). These are different than the Enphase in that they are DC. They are MPPT (max power point tracking) and work very, very well but there is also an interface inverter to the grid.
These panels are on the new garage roof, 28 panels, east/west orientation. I built the garage knowing at some point that I would put panels on it so when I bought my trusses I told the manufacturer to engineer them for 24' on center BUT give me enough for 16" on center. I wanted a strong roof.

There's a problem with roofs in cold climates, it's called snow, so if you live in a place that gets snow than keep your panels as low to the ground as you can if you plan on cleaning them off like I do. It's not that bad cleaning them ( I bought one of those extension booms with a pad on the end) but if I didn't have to I wouldn't miss it!. The system was free from a grant so you get what you can get and don't look that old gift horse in the mouth!

My other system is an off grid/intertie. When my batteries are charged I sell back to the grid so basically, since I don't need to run off grid, excepting during emergencies, I'm selling everything back that I don't use running my house. This is hands down the best way to go if you can. Your batteries last indefinitely and when you have a power failure they run the house. Perfect!

My intertie system is tied to my computer. I can check my panels and see how much power I'm making or have made since the system was installed.

Here's a snip of the computer display:

Rob

08-19-13, 05:35 AM	#1
The master plan Helper EcoRenovator Join Date: Oct 2010 Location: Central MN Posts: 50 Thanks: 0 Thanked 4 Times in 4 Posts	Solar question/s Looking over the posts and such...guessing from my location and partial shading at times in summer and leaving branches in winter to somewhat shade.... I am thinking the mini inverters would be best for a new install. Does it matter than if the panel themselves have the bypass diodes then? Some solar panel sellers here haven't even heard of a panel with bypass diodes or know what it is. This would be for a later date install, if I can justify the costs vs payback and capability. If you are following the my other posts I am thinking about my garage roof. 270sq feet of really good in summer and 240 sq feet of somewhat good(lower level of roof) The upper would receive nearly shade free all year, at least until my neighbors tree grows taller, unless the ash borer gets it first. Other concern is weight on roof. Also with the mini inverters what else is needed to net meter? There is a new digital meter on the house now. I want a grid tie system and would convert to off grid if possible at a later date when I can generate enough power myself. This would have to include 220v also. I can use as much as 600kw to as low as 260kw a month. Crazy me lives in town also, but I am close to disconnecting from the city heat (no gas line to house, its hot water from coal plant) and want to start a plan for electric also. There seems to a trend developing of charging more for the meter/access to power than the consumption of it. Several gas suppliers have said a drop in assuage has forced them to charge more for a meter. My own city has said the water meter will cost more because of the same. Its a steady line of cash and can never go down with green power or conservation. On the plus side we have two 2MW wind turbines in town also. But they might as well outlaw home turbines with their max height ordnance.

08-19-13, 09:26 AM	#3
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 114 Thanked 250 Times in 230 Posts	EnPhase publishes a list of compatible panels for each of their inverter models. __________________ My hobby is installing & trying to repair mini-splits EPA 608 Type 1 Technician Certification ~ 5 lbs or less..

08-21-13, 06:28 PM	#6
Robaroni Journeyman EcoRenovator Join Date: Jun 2013 Location: Delhi, NY Posts: 332 Thanks: 20 Thanked 53 Times in 40 Posts	I agree about the diodes, someone doesn't know don't buy from them. I have a roof system with microinverters (SolarEdge). These are different than the Enphase in that they are DC. They are MPPT (max power point tracking) and work very, very well but there is also an interface inverter to the grid. These panels are on the new garage roof, 28 panels, east/west orientation. I built the garage knowing at some point that I would put panels on it so when I bought my trusses I told the manufacturer to engineer them for 24' on center BUT give me enough for 16" on center. I wanted a strong roof. There's a problem with roofs in cold climates, it's called snow, so if you live in a place that gets snow than keep your panels as low to the ground as you can if you plan on cleaning them off like I do. It's not that bad cleaning them ( I bought one of those extension booms with a pad on the end) but if I didn't have to I wouldn't miss it!. The system was free from a grant so you get what you can get and don't look that old gift horse in the mouth! My other system is an off grid/intertie. When my batteries are charged I sell back to the grid so basically, since I don't need to run off grid, excepting during emergencies, I'm selling everything back that I don't use running my house. This is hands down the best way to go if you can. Your batteries last indefinitely and when you have a power failure they run the house. Perfect! My intertie system is tied to my computer. I can check my panels and see how much power I'm making or have made since the system was installed. Here's a snip of the computer display: Rob Attached Thumbnails

08-19-13, 09:04 AM	#2
pinballlooking Super Moderator Join Date: Jun 2013 Location: SC Posts: 2,923 Thanks: 172 Thanked 564 Times in 463 Posts	You need to look at Gary’s and Doug’s projects. http://www.builditsolar.com/Projects...asePV/Main.htm Designing and Installing a Grid-Tie PV System and Doug http://www.builditsolar.com/Projects...ougEnphase.htm They did a great job of documenting micro inverters and the process.

08-19-13, 09:31 AM	#4
pinballlooking Super Moderator Join Date: Jun 2013 Location: SC Posts: 2,923 Thanks: 172 Thanked 564 Times in 463 Posts	here is the list for the M-215 micro inverter by Enphase. http://enphase.com/wp-uploads/enphas...ility_List.pdf

08-19-13, 10:50 PM	#5
where2 DIY Geek Join Date: Apr 2013 Location: Sunny Florida Posts: 401 Thanks: 74 Thanked 83 Times in 73 Posts	Avoid the solar panel sellers who don't know what bypass diodes are. There are plenty of reputable places selling panels ridiculously cheap. If going grid tie, you want a UL listed panel. That M-215 list is a good place to start. As for weight on the roof, a 220W-235W 60 cell panel is roughly 3'x5' and weighs ~45lbs. That's 3lbs per square foot (in the horizontal plane, roughly 7lbs at a 45°). As you will note, the load increases when you consider the tilt involved, but it's not as if it is 50lbs per square foot. Don't forget to look at snow load though. (In FL, I ignore show load.) As for "new digital meter" vs. "net meter": the GE i210+ Smart Meters come programmed from GE to accumulate forward whether they are reading "Received" or "Delivered" (like a car odometer, they don't go backward). If you don't tell the POCO, and you back feed an ordinary GE i210+ without telling them, you end up paying the POCO for the pleasure of giving them free power. My utility brought me out a completely different brand "Landis + Gyr" as a bi-directional meter, and took away my GE i210+. If you think "base billing fees" are expensive, you haven't priced self-generation. A set of batteries for autonomous generation makes my $7/mo base billing fee look like a bargain. My $56/mo water + sewer bill looks expensive, until I listen to my friends with wells talk about softener salt, bottled water and all the other things they deal with to use what they pump out of the ground, and drop into their septic systems. Then my $56 actually looks cheaper than the alternative.