UI has observed testing of the PV system's inverter in operation.
Commonly referred to as a "solar system", a photo-voltaic (PV) system has many components. First of course are the panels where photons are converted to electrons. Those electrons move in a direct current (DC) type of manner - much like electricity in your automobile. This current is sent to an inverter which changes the electricity to an alternating current (AC) with correct phase, frequency, voltage and other aspects that will match what is being delivered from the utility so it "marries" properly. Lastly, the meters record what is being consumed and generated for the utility company.
Important to the utility company is correct equipment that "marries" with theirs and will not damage their infrastructure. They confirm this through testing that they witness - thus the term "witness test".
We did our test today, and were given the ok to run our system. Once we have some averages and time to generate reflective data, I'll update the blog with information. Till then, here is a video of our installer's representative explaining our witness test while it was happening.
Monday, March 23, 2009
Friday, March 20, 2009
Solar operations - Metering
UI has installed meters to record both what is generated, and what is consumed.
With solar installations, you both consume an amount of electricity and generate an amount of electricity at the same time. Some solar installations areas are able to get by with one meter. Consumption tries to move the meter forward (as it normally operates), while generating tries to move the meter backwards. If the solar array generates less electricity than what we consume, the meter's pace toward moving forward is reduced. This is what's called "net-metering".
Connecticut is a "net metering" state under Dept of Public Utility Control regulations. At our location, United Illuminating is the delivery agent for electricity. You can buy your electricity from a number of sources (including UI), but the delivery infrastructure (poles, lines, transformers, meters, etc) are owned by UI. It is UI as the delivery agent that carries out all the metering and billing work.
If over a billing period, we generate more than we consume, the "bill" for electricity "use" will be a negative number, and UI's billing system can not properly address that (UI likely has algorithms that monitor usage patterns to detect fraud). Thus, UI requires 2 meters to be installed. (see above photos) Meter A records how much we consume. Meter B records how much we generate. Meter A minus Meter B is what we are billed upon.
Installing the new meters required co-ordination with IDA's workplace, as the power was required to be shutdown to the building. Before UI would install the 2 meters, the City of Derby electrical inspector was required to close-out our permit with an inspection. Before that could happen, some final housekeeping work had to be completed on the DC side of the system on the roof - which was difficult due to weather. Delays, delays.
So, finally after weather improved and final workmanship was completed, we could schedule the City of Derby inspection (which Derby delayed a week due to scheduling conflicts). When the electrical inspection was done, we scheduled to have the meter work done (which UI delayed for a week due to scheduling conflicts). Now with meters in place - we can schedule a witness test of the entire system.
With solar installations, you both consume an amount of electricity and generate an amount of electricity at the same time. Some solar installations areas are able to get by with one meter. Consumption tries to move the meter forward (as it normally operates), while generating tries to move the meter backwards. If the solar array generates less electricity than what we consume, the meter's pace toward moving forward is reduced. This is what's called "net-metering".
Connecticut is a "net metering" state under Dept of Public Utility Control regulations. At our location, United Illuminating is the delivery agent for electricity. You can buy your electricity from a number of sources (including UI), but the delivery infrastructure (poles, lines, transformers, meters, etc) are owned by UI. It is UI as the delivery agent that carries out all the metering and billing work.If over a billing period, we generate more than we consume, the "bill" for electricity "use" will be a negative number, and UI's billing system can not properly address that (UI likely has algorithms that monitor usage patterns to detect fraud). Thus, UI requires 2 meters to be installed. (see above photos) Meter A records how much we consume. Meter B records how much we generate. Meter A minus Meter B is what we are billed upon.
Installing the new meters required co-ordination with IDA's workplace, as the power was required to be shutdown to the building. Before UI would install the 2 meters, the City of Derby electrical inspector was required to close-out our permit with an inspection. Before that could happen, some final housekeeping work had to be completed on the DC side of the system on the roof - which was difficult due to weather. Delays, delays.
So, finally after weather improved and final workmanship was completed, we could schedule the City of Derby inspection (which Derby delayed a week due to scheduling conflicts). When the electrical inspection was done, we scheduled to have the meter work done (which UI delayed for a week due to scheduling conflicts). Now with meters in place - we can schedule a witness test of the entire system.
Tuesday, February 17, 2009
Solar Panels in Final Testing
Cold weather has impacted the 3rd parties who must test the solar array.
We had a very cold winter in Derby, CT this year with lots of snow and prolonged sub-freezing cold periods. This has impacted the testing and 3rd party verification of the array since the roof is accessed from the north facing slope which is in the shade most of the day with the low winter sun, causing snow or frost to linger and make it unsafe to climb. Also, the inverter and associated equipment is in a courtyard where snow sheds off a standing seam roof - see the photo to the right to see the look after a partial snow-slide. Safety is not an option in putting this solar array together, so we had to wait out mother nature.
The photo-voltaic array has been operational, and only testing has been complicated by the weather. The interconnection agreement has been signed with the utility, and it calls for 3rd party verification of equipment attaching to their infrastructure. They also have to witness a test that the system will automatically shut-off in case of a local area power failure. Although the system is fully functional, I am prohibited from even running it in parallel to the electric utility's system - so I must wait.
The utility additionally relies on local building inspectors to confirm that the work interior to the private property is done to code and they have issued a "CO" or "Close-Out" (sometimes called a Certificate of Occupancy) of the work. Derby's electrical inspector is part-time 1day per week, thus far he has only inspected the AC side of the system, and the DC side of the inverter requires access to an area where this snow was causing hazard (snow guards were planned to be installed once this roof access activity was finished). Also the building inspector must say the structural work was completed according to the structural engineer's design (I hired a 2nd structural engineer to inspect the work as the building inspector asked me to provide that verification - besides the welders license that my employee had who did the work).
There have been NUMEROUS questions about our array and when it will be throwing out electricity, how much power is generated, etc. We will have a webpage to dynamically present that data, but till then I offer the following photos taken when we briefly tested the system. During the 5min of operation at 3pm (sun getting low in the sky), the air temp was mid 50's, sunny sky clear with no clouds. Input was DC 375Volts at 178Amps. Output was AC 61.3Kw.
We had a very cold winter in Derby, CT this year with lots of snow and prolonged sub-freezing cold periods. This has impacted the testing and 3rd party verification of the array since the roof is accessed from the north facing slope which is in the shade most of the day with the low winter sun, causing snow or frost to linger and make it unsafe to climb. Also, the inverter and associated equipment is in a courtyard where snow sheds off a standing seam roof - see the photo to the right to see the look after a partial snow-slide. Safety is not an option in putting this solar array together, so we had to wait out mother nature.The photo-voltaic array has been operational, and only testing has been complicated by the weather. The interconnection agreement has been signed with the utility, and it calls for 3rd party verification of equipment attaching to their infrastructure. They also have to witness a test that the system will automatically shut-off in case of a local area power failure. Although the system is fully functional, I am prohibited from even running it in parallel to the electric utility's system - so I must wait.
The utility additionally relies on local building inspectors to confirm that the work interior to the private property is done to code and they have issued a "CO" or "Close-Out" (sometimes called a Certificate of Occupancy) of the work. Derby's electrical inspector is part-time 1day per week, thus far he has only inspected the AC side of the system, and the DC side of the inverter requires access to an area where this snow was causing hazard (snow guards were planned to be installed once this roof access activity was finished). Also the building inspector must say the structural work was completed according to the structural engineer's design (I hired a 2nd structural engineer to inspect the work as the building inspector asked me to provide that verification - besides the welders license that my employee had who did the work).
There have been NUMEROUS questions about our array and when it will be throwing out electricity, how much power is generated, etc. We will have a webpage to dynamically present that data, but till then I offer the following photos taken when we briefly tested the system. During the 5min of operation at 3pm (sun getting low in the sky), the air temp was mid 50's, sunny sky clear with no clouds. Input was DC 375Volts at 178Amps. Output was AC 61.3Kw.
Wednesday, January 21, 2009
U.S. Green Building Council
IDA International Inc. has joined the U.S. Green Building Council.
Several of our recent projects have attained LEED ratings for their construction methods. IDA has long held the same beliefs and practices upheld by the USGBC, and our membership with them formally indicates our support of their ideals.
The USGBC is a 501(c)(3) nonprofit membership organization with a vision of a sustainable built environment within a generation. Its membership includes corporations, builders, universities, government agencies, and other nonprofit organizations. USGBC is dedicated to expanding green building practices and education, and its LEED® (Leadership in Energy and Environmental Design) Green Building Rating System™.
Wednesday, December 31, 2008
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.
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.
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!
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!
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