Rather than derail Luvit's 800kWh/month conservation challenge thread, it was suggested I start my own on the subject of DIY photovoltaic solar.
First, a little intro: About a year and a half ago, the economy was in the pits and I found myself with lots of time on my hands. I've got a 4 year degree from a darn good university, but nobody ever taught us how to weather an economic disaster in my chosen field of Surveying and Mapping. I'd already gotten bored, studied and passed an exam for a license in another state. Unfortunately, neither Florida nor Maine has a great need for licensed surveyors at the moment. So, I happened to be perusing the class offerings at the local community college 18 months ago and noticed they were offering an introductory course in solar energy as a class in their Electrical Power Technology systems program. So, I signed up for it and coughed up my $270 course fee with the thought in mind that being an educated consumer is a good thing when it comes to purchasing new technologies. After my first night of class, I was telling my dad about the class and next thing I knew he signed up for it. So, there we were, father and son taking the same class. My dad spent 33 years working for a local aerospace firm working as an electronics technician, the electrical theories were no sweat to the oldest guy in the class.
For the final project in this class, each student had to come up with a concept, do research about it, compute the cost to implement the project and project what the benefit would be. The project I came up with was the modular PV solar array. By the time my project was done, I had a single line diagram suitable for handing to the local AHJ.
The system relies on whoever has the least expensive solar panels capable of driving a micro-inverter (60 cell panels @ ~30v). In my case, I bought a pallet of twenty Evergreen 220W modules for $0.78/W. The bankruptcy of Evergreen left dirt cheap panels on the market late last year when I bought these. Realizing when I'd done my calculations in April, for my class project, panels were running $1.98/W, I saw that the Evergreen panels were an incredible bargain, even if they really didn't have any warranty. As I later watched other big name panel manufacturers declare bankruptcy, I came to realize PV Solar really is going to be hit or miss if you have a panel failure down the road and need to file a warranty claim. So, self-insure, buy extra panels, especially if they are cheap!
A panel is only the beginning of the equation, next you need to drive an inverter to turn DC solar power into AC grid power. For that, my project will rely on micro-inverters, because I have shading issues, and because I have a 2-story house where running heavy gauge DC wiring from the roof to a central inverter would be a logistical nightmare. Then there is the fact that I have a small one car garage with a small work area, located 10' from my load panel. I'm short on physical space indoors! Bringing two 12 gauge 15A 220V circuits from the second floor roof to the load panel is just easier since my electric meter box has a built-in breaker panel with spare room in it on the exterior of the house. My inverters of choice are the Enphase M215's. They run as low as $150 each from some online merchants, watch out for shipping costs though!
One of the beauties of the Enphase system is the ability to monitor output of each panel individually. To do this, you need an Enphase Envoy Comminications Module to listen to the power line communications data that each inverter sends down the neutral wire. For that, I found my local Lowes coupon for $25 off a purchase of $250 or more. Then I found the Westinghouse communications module for $512, less $25, shipped to my local Lowes for free.
I ordered the Westinghouse device, but the box, instructions and the device itself are all straight Enphase product.
The reason my panels are in my garage and not on the roof yet is the racking challenge. Sticking a giant sail to your roof, and getting a structural engineer to buy off on the design is a challenge when you live where hurricanes frequently make landfall. I'm looking for a rack design capable of withstanding 150MPH winds! My other criteria is that the mounts not put 87 holes in my Decra stone coated metal roof. Tile hooks would be fine, but finding engineering specifications on anyone other than Unirac's tile hooks is a challenge!
Got questions? Ask away. For anyone contemplating a similar system who doesn't live where you get 150mph winds, check into the largest Westinghouse system that Lowes sells. The single and 4 panel setups are rather steep pricing for DIY, but they do seem to come well equipped. The 20 panel kit for $12,500 (235W panels) is actually the best value, especially if you get an extra 5% discount for using your Lowes Charge.
My goal is to offset 600kWh of my electric per month using net metered solar.
First, a little intro: About a year and a half ago, the economy was in the pits and I found myself with lots of time on my hands. I've got a 4 year degree from a darn good university, but nobody ever taught us how to weather an economic disaster in my chosen field of Surveying and Mapping. I'd already gotten bored, studied and passed an exam for a license in another state. Unfortunately, neither Florida nor Maine has a great need for licensed surveyors at the moment. So, I happened to be perusing the class offerings at the local community college 18 months ago and noticed they were offering an introductory course in solar energy as a class in their Electrical Power Technology systems program. So, I signed up for it and coughed up my $270 course fee with the thought in mind that being an educated consumer is a good thing when it comes to purchasing new technologies. After my first night of class, I was telling my dad about the class and next thing I knew he signed up for it. So, there we were, father and son taking the same class. My dad spent 33 years working for a local aerospace firm working as an electronics technician, the electrical theories were no sweat to the oldest guy in the class.
For the final project in this class, each student had to come up with a concept, do research about it, compute the cost to implement the project and project what the benefit would be. The project I came up with was the modular PV solar array. By the time my project was done, I had a single line diagram suitable for handing to the local AHJ.
The system relies on whoever has the least expensive solar panels capable of driving a micro-inverter (60 cell panels @ ~30v). In my case, I bought a pallet of twenty Evergreen 220W modules for $0.78/W. The bankruptcy of Evergreen left dirt cheap panels on the market late last year when I bought these. Realizing when I'd done my calculations in April, for my class project, panels were running $1.98/W, I saw that the Evergreen panels were an incredible bargain, even if they really didn't have any warranty. As I later watched other big name panel manufacturers declare bankruptcy, I came to realize PV Solar really is going to be hit or miss if you have a panel failure down the road and need to file a warranty claim. So, self-insure, buy extra panels, especially if they are cheap!
A panel is only the beginning of the equation, next you need to drive an inverter to turn DC solar power into AC grid power. For that, my project will rely on micro-inverters, because I have shading issues, and because I have a 2-story house where running heavy gauge DC wiring from the roof to a central inverter would be a logistical nightmare. Then there is the fact that I have a small one car garage with a small work area, located 10' from my load panel. I'm short on physical space indoors! Bringing two 12 gauge 15A 220V circuits from the second floor roof to the load panel is just easier since my electric meter box has a built-in breaker panel with spare room in it on the exterior of the house. My inverters of choice are the Enphase M215's. They run as low as $150 each from some online merchants, watch out for shipping costs though!
One of the beauties of the Enphase system is the ability to monitor output of each panel individually. To do this, you need an Enphase Envoy Comminications Module to listen to the power line communications data that each inverter sends down the neutral wire. For that, I found my local Lowes coupon for $25 off a purchase of $250 or more. Then I found the Westinghouse communications module for $512, less $25, shipped to my local Lowes for free.
I ordered the Westinghouse device, but the box, instructions and the device itself are all straight Enphase product. The reason my panels are in my garage and not on the roof yet is the racking challenge. Sticking a giant sail to your roof, and getting a structural engineer to buy off on the design is a challenge when you live where hurricanes frequently make landfall. I'm looking for a rack design capable of withstanding 150MPH winds! My other criteria is that the mounts not put 87 holes in my Decra stone coated metal roof. Tile hooks would be fine, but finding engineering specifications on anyone other than Unirac's tile hooks is a challenge!
Got questions? Ask away. For anyone contemplating a similar system who doesn't live where you get 150mph winds, check into the largest Westinghouse system that Lowes sells. The single and 4 panel setups are rather steep pricing for DIY, but they do seem to come well equipped. The 20 panel kit for $12,500 (235W panels) is actually the best value, especially if you get an extra 5% discount for using your Lowes Charge.
My goal is to offset 600kWh of my electric per month using net metered solar.
I want pictures, I want stats, and I want to see you up there sweating! 
I've been optimizing things and killing phantom loads since I read Luvit's 800kWh challenge thread. I was right around 1100kWh last month. 
As a native Floridian with 40+ years experience, the grid is actually up >99.8% of the time. When the grid is not up, I have a generator, and a portable 2cuft Norcold AC/DC refrigerator/freezer. I also have a 50W and/or a 20W 17V(DC) solar panel along with a Morningstar SL-10L-12. If I need more charging capacity, I have plenty of 36V panels... Wonder what I could do with those? 