Saturday, December 22, 2012

Solar PV Project

The shed was in for a few weeks and then it was time to do the Solar PV Project.

The idea to "go solar" comes from an intererest to both cut our electric bill (PECO charges about 16-17c per kWh in SE PA) and to help fuel the Chevrolet Volt we purchased in summer of 2012.  With a clear sky and southern exposure, the backside of the shed was always to be used for this Solar project.  Rather than a ground-mount for the entire Solar PV array, we went with a 1/2 roof and 1/2 ground solution.

In August, 2012, we started to choose the equipment.  I did want to use USA-made components and not choose items imported from other countries.  Our nation needs continued jobs and I felt it would be best to pay the premium for the locally-made products.  Saving $1-2K on the project wasn't worth the mindset of not supporting our nation.  My kids may, some day, work in an industry that we support and carry forward now.

First negative was that my township charged a permit fee based on per square-foot of the array.  The shed's permit was $25 and the solar permit was over $270.  They randomly chose to use .50/sqft for the permitting fee.  It seems they are gouging those who are putting in "one of them there fancy-dancy solar things".  There is national movement to try to make permitting of solar installations smoother and lower-fee to incent more people to do installs.

On to the Solar PV setup.  Total peak power capacity is 8.16KW based on the module numbers.  Maximum output is roughly 8.0KW when the inverters hit their maximum AC power.  Over time, modules will degrade and will not hit these maximums but for the first few years, I hope we can hit the 8.0KW peak output on many good sun days.

This system is a 32-module array - actually two 16 module arrays - made up of

- 32 SolarWorld SW 255 Mono-crystalline Version 2.0 panels.  Each can make up to 255W of peak power.
- 2 PowerOne Aurora PVI-3.6 inverters
- Schletter ground-mount racking
- Pro Solar roof racking

Step 1 - Install the modules on the roof.  That's Misty, the miniature poodle wondering when the rabbit will come out from under the shed. The rabbit moved from under the old shed to this new one quickly.

Step 2 - reviewing the installation, the cable combiner box really wasn't right on the roof.  This is to be removed and wires rerouted.  Don't put up with installation steps which can be done better.

Step 3 - with combiner box now removed and roof-mounting cut down, the team adds the ground mount modules.

You will also notice the lower array is positioned over the grass area.  The guys did come back and pushed the whole array back, using jacks, so that the lower edge is behind the wooden border.  I have to say the installation team was very helpful in making everything right.
Roof rack angle is 39* and ground mount angle is 35*.  Since they are not tiltable, they may not produce the maximum possible during the summer months' high-sun and daytime heat.  But I do know that they can produce at full power during December days' peak sun as we have already seen this happen soon after installation.

Finished arrays:

Step 4 - The team then added the wiring and internal components for the inverters.
Shown here are two inverters - one for the roof and one for the ground mount.
A combiner breaker box taking both inverters' output into one 240V power output.
Also, a production meter (for possibly tracking production for SRECs).
And lastly, a small breaker box so we can install some lights and plugs into the shed.

The power is routed to the house 18" underground in a pvc pipe and then connected up outside using a "service side" interconnection.  No internal wiring was done to backfeed into the main 200A service breaker box.  This photo shows the meters before commissioning.  PECO, our local electric company came out to install two "Detented" meters allowing for proper metering for Net-Metering.  With the original home meter, if the Solar PV produced electricity back to the grid, the meter would still "spin-forward" digitally and you would pay for the electricity you sent to the grid.  Nobody wants that.  Using two meters for a net-meter configuration allows proper billing.

The shed doesn't look too bad after all the work.  We don't have a lot of neighbors around and so the big array shouldn't stand out too much.
The array is a total of 8.16KW.  The inverter maximum output is 4KW each so the array really is a 8KW maximum power output system.  I have seen it hit the maximum of just over 4KW per array on a cold day in December so I know that it is working properly.  We have had a number of cloudy days since it was commissioned so hopefully soon, we will have some good sun to put out some serious output.  On Dec 3-5, before it was properly commissioned, we had the array on for two test days and each day, the array put out over 50 kWh each day.

This system was built by Smucker's Energy, LLC of Kinzers, PA


  1. hi. thanks for sharing such an amazing and interesting post. it was quite inspiring

    Solar PV Mount

  2. Hi, Nice solar set up. I wonder what your annual demand for power is coming from the Volt? I know it depends on your usage as in do you deplete the Volt each day of the week or not? I am getting a 10.7KWh array set up next month. (SolarWorld as well)I don't have a Volt yet, I still have year left on my current lease and I am trying to figure out what I will still draw from the grid. The system was designed to slightly over produce on the current demand of our house.

  3. Annual demand for volt charging will be based on the number of times recharging. It takes about 12.5 kWh for a full charge. I don't recharge every day. So, I estimate about one recharge every 3 days. My wife is I retreated in getting a volt as well and we may do that later this year.

  4. Nice setup Bonaire! I bet it produces really well, and love the shed too.

    Here are a few shots of my shack!