Inspections

We have reached a point of completion where inspections are done. The City of Derby electrical inspection was done last week and everyone was satisfied. Today a Proffessional Engineer looked at our truss work and that was satisfied. So the system has reached a completion point, but due to some weather issues (today is a snow storm) we have had to hold off on flipping the switch until after the holiday.

I have focused on the hi-tech side of our installation, but the building structure itself had to be reinforced to satisfy the design engineer and building dept. It was a very difficult to access area that required some special rigging of ladders and safety harnesses, and the work was done by one of our employees who is a certified welder from Local 580 Ironworkers Union in NYC.

The below photos are a closup of a truss, a view of trusses over the shop manufacturing space, and a view of the trusses over the warehouse area. The building was constructed in the late 1800's with primarily riveted steel construction, and was first used to make cannons.

Pulling the cables

The conduit and junction boxes are nearly all in. Now it's time to pull some cable through them.

Below is a photo from the ridge looking north/west with the Lake Housatonic in the background. The strings are wired into collector boxes and into junction boxes and then on to the inverter.

Next is a close-up of a collector box where the strings of panels are brought to a location for combining into a bigger wire.

Once past the inverter and converted into alternating current, the electricity runs on some heavy cable that you can see here being readied for pulling through the conduit. In addition to 4 electricians in photo, there was another 3 guys on the pull wheel at the other end.

Given weather issues (snow, ice, frost, cold, wind) we have been impacted from staying on schedule, but hope to have everything in place and inspected before the holidays. Click on any photo to see it in larger format.

Beyond the solar panels - piping, cables, inverter

The electricians are hard at work dancing around the weather and supply deliveries.

After the panels generate electricity, the DC current is converted to AC and tied into the grid. The Solar panels will be generating electricity in a DC (direct current) form. This is routed by cable within heavy galvanized conduit to an inverter. You may have seen this type of a device that plugs into a car 12 volt outlet (also DC) and converts it into AC (alternating current) form for DVD players or shavers, and ipods. This inverter obviously does a bit more.

In addition to converting from DC to AC, there is synchronization needed with the utility's electricity, and this has a monitoring device that delivers a data signal showing how much electricity is being generated (which I can then format and publish live in a streaming format on the internet). Coming out of the inverter will be AC current that is carried in a similar heavy galvanized conduit, leading to a big on/off switch. This is required by the utility and the fire department. In case of an area outage, they have the ability to "throw the switch" and prevent my solar panel "power plant" from dumping live juice into the electric grid.

Below is the inside "guts" of the inverter, and the electrician installing the on/off switch. It is a very big switch!

525th panel is installed on the 9th day

The last panel was attached to the roof today, Nov 26th, 2008

Yesterday (Tue) was a washout for weather, but today the morning frost gave way to temps in the upper 40's with cloudy skies and the crew installed 70 panels to complete the 525 panel array. There are still connections to be made with combiner boxes and working the wires carrying the clean energy toward the inverter, but that will come after the Thanksgiving Holiday.

The electrician sorted out his final permitting last night, and our permit is in place to finish off the connection from the inverter onward to an emergency shutoff switch (in AC) and into our meter. This is so the utility can shut us off from dumping live juice into the grid in case of an emergency. More on the electrical / technical side of the project next week.

You will note in the below video, at the beginning, you see a good sized area of the roof without panels. Yes, the system can be expanded even further as our business grows. We chose to size the system to match our consumption, since if we generated more than we consume, the electric utility only pays a wholesale rate for that electricity, and thus the "extra" panels do not have a feasible return on investment.

Where there are no PV panels, you can see the roof material is quite reflective. It is "Galvalume Plus" metal used in the standing seam roof. It reflects a significant amount of the radiant energy, and thus reduces the cooling load on the building (for which there are tax credits if you are considering a similar course of action). For our purposes, it also reflects back onto the panel. About 15% of the panels surface area is translucent. Of that light that passes through and hits the roof, 60% of it is reflected back based on the emissivity of the metal. Of that reflected energy hitting the back of the solar cells within the panel, there is a certain amount of electricity generating "bonus". These PV panels are a newer model, and are somewhat a "proof of concept" for their efficiency given the roof material.

Solar nearing the last panel

The Solar panel installation continued on Monday, but it looks like we have hit bad weather.

With a bit warmer weather today, we neared the end of installing the 525 panel system (still have apx 70 left to go). I had a photo-journalist from the CtPost with me taking photos for an upcoming article, so we hoisted the boomlift up pretty high for these shots.

Our building was built in the late 1800's and you can see other similar mill-buildings in the valley next to the Housatonic River. My hope is that other industrial building owners might see the potential to cast a new view on their property with an eye toward making them "greener".

The left photo shows a view of neighboring mill building factories with a glimpse of the Housatonic River and Route 8 bridge in the far background. The right photo is the panel array as of Monday afternoon (about 434 panels are in the photo, the entire system will be 525).

Cold, but install continues

This morning, the temperature was in the upper teens, and there was a frost on the roof, but there was no precipitation, so we kept on installing.

I thought it would be nice to see what it is like from above, since all previous photos have been taken from the ground. At mid-day Saturday, we have 259 panels on the building, so just about halfway done. The weather doesn't look good on Mon/Tue and Thu/Fri is Thanksgiving, so thus the work this weekend to try and keep on pace.

If you look at the ridge of the 2nd photo, you can see where the strings feed to a combiner box. They then route via cable to an inverter that's located on the otherside of our building (in a sheltered courtyard - more efficient when kept cool) where it will convert from direct current (DC) to alternating current (AC) and be tied into the electric utility grid operated by United Illuminating.

Panels over 150 mark

The good weather continues for our installation of solar panels, helping us reach 160 on the building by day #3.

The weather has been quite cold yesterday and today (upper 30's, low 40's), but yesterday's wind has subsided today, and it was quite workable. Thus, the installing crew diversified their tasks because as the mechanical attachment continues, the strings of panels need to have cables routing the electricity to combiner boxes. 7 panels attach in series to form a "string". 8 strings come together in a "combiner". The combiners then come to a junction box, and the cable runs to an inverter. The layout of the panels on the roof involves not only how many can physically be placed in the space, but how they connect electrically in the most efficient manner.