Wednesday, December 31, 2008


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.

Monday, December 15, 2008

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.

Thursday, December 4, 2008

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!

Posted by Picasa