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Tue May 3, 2016, 02:57 PM


An interesting DIY solar power project at Kickstarter

x-posted from GD.

Disclaimer: I am not endorsing this project, nor do I have any interest in it, financial or otherwise. I do not know anyone associated with the company, but I have bought a flashlight from the company. I currently have a roof mounted 7kW array, so I do know a bit about what these things require:


Summary: This is a small scale, "plug and play" solar array, designed to avoid contractor expense, which is about 2/3s of the cost of a traditional array. They use a "side mount" roof bracket to eliminate the need to run holes into your roof (which MUST be done correctly or your roof will leak). The side mount bolts into the eaves of your roof. You can also place it on your lawn with a simple "a-frame" set up.

Instead of hard-wiring the system into your breaker box, you plug it into an existing outlet, and it syncs up with your house's AC power and feeds into the system. This leads to my first caveat, the system can ONLY produce power while grid power is active. If you lose power from the grid, you lose array power.

My second caveat is that their savings calculations are based on electrical rates in San Jose, which are about 3 times the national average of 12 cents/kWh.

The third caveat is that these are pretty low wattage panels (100 watts, versus 250-300 for most panels today) in order to be light enough to avoid code requirements about installation (getting a permit, specifically, in order to install heavier panels on a roof and inspecting the roof to verify they can handle the load).

The fourth caveat is: It's a Kickstarter project.

Fifth caveat is that they mention the 30% federal tax credit, but will probably not be shipping until 2017. The credit expires 12/31 of this year, and with the current congress, very unlikely to be renewed. Your state, however, may be a different story.

With all that in mind, it seems an interesting enough project for folks with spare cash and a desire to play with a project of this type. Will it save you money? That depends on a LOT of factors. It seems to me, a neat way to get your feet wet, maybe do it as a family project with the kids. It also seems like a neat way to offset the power used for a BEV, or plug in hybrid.

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Reply An interesting DIY solar power project at Kickstarter (Original post)
Kelvin Mace May 2016 OP
mackdaddy May 2016 #1
Kelvin Mace May 2016 #2

Response to Kelvin Mace (Original post)

Tue May 3, 2016, 11:58 PM

1. A few details and items I did not see addressed....

I designed and installed my own 10kw system, and was the main instructor for an associate degree program in Advanced energy at a local technical college for a few years.

You can buy just the components kits from most solar distributors for about 1.50 to $2 a watt. This system is a microinverter system meaning a small individual inverter to produce the needed ac on each panel (or small group of panels). The photos they are showing is plugging into a 110vac outlet, but most inverters are 220/240vac, and the higher voltage would probably be better. You would definitely want a waterproof place to plug the system into too.
A couple of technical details. Most inspectors and power companies will want a certified electrician to do the wiring at least to the outlet connection. Fire codes require a separate breaker and external disconnect to shut down the system in case of fire.
You also have to fill out quite a bit of paperwork and have the basic system inspected by the power utility company. The power company also has to replace the standard meter with a "net" meter and change the account over to net metering. Standard "smart" meters will actually accumulate as usage billed to you even for power you send to the power company. (You actually pay for the power you send to them on these meters, so you must sign up for the "net" meter.) AEP charged me about $500 to change out to the net meter. If you want credit for the Solar Renewable Energy Credits, you also may need your own private production meter, and sign up for the SREC program for your area.
There are a few checks that a qualified electrical engineer/electrician needs to make to insure your house wiring will take the extra power requirement.
Finally, mounting this stuff on your roof can be a little tricky. You have to make sure that the holes you are putting through your roofing will NEVER leak. Water damage can be the worst from even a small leak. The other detail is that all the square footage of panel act as a large sail in the wind. You have to make sure the fasteners used are strong enough, and have enough holding power to hold in the local max wind usually at least near 100mph. The roof trusses also needs to be evaluated that it can hold the extra weight of the panes and additional wind load/snow load.
I am not saying you cannot do all of this yourself, just be aware of these details the installers usually take care of.

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Response to mackdaddy (Reply #1)

Wed May 4, 2016, 12:08 AM

2. I have been re-reading through this


And they seem to be feeding power via microinverters back into the home system using main current to sync up. So, you would need to be careful to size your system so that your daytime draw will not be less than you are pulling in from the panels.

They do talk about different breaker ratings depending on how big your system is and being able to be connected to 220v circuits.

They claim their mounting brackets are rated to 70 mph, whereas my roof mounts are rated to 120 mph. I would probably ground mount this type of system.

I would definitely want an electrician to look over this.

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