Here are some pictures of where the disconnect will go, namely in between the meter and the Fronius.... notice the dual-meter "can" with only one active meter (the one that feeds our house).
Friday, April 10, 2009
Need an AC disconnect for the solar panel
The Duke Energy engineer determined that we would need to have an AC disconnect, even though the Fronius inverter automatically disconnects when it detects a power failure. Here is the AC disconnect, which is waiting to be connected.
Here are some pictures of where the disconnect will go, namely in between the meter and the Fronius.... notice the dual-meter "can" with only one active meter (the one that feeds our house).
Here are some pictures of where the disconnect will go, namely in between the meter and the Fronius.... notice the dual-meter "can" with only one active meter (the one that feeds our house).
Saturday, February 14, 2009
Friday, February 6, 2009
Steps to getting your solar panels on the grid in NC
I find myself repeating many aspects of the solar-panel saga, so I thought that I would write them down here, so that you might benefit.
I will revise these notes as I go along.
Notes on installing the solar panels
Love the folks at Solar Electric Supply. From them, I bought a kit including:
We picked them up from the local Roadway trucking distributor in two trips. (That's one of the reasons Charlotte is popular with trucking companies: I-85 and I-77 intersect here.)
We oriented the house so that the long dimension was facing south. The roof angle was close enough to our Longitude of 34 degrees that we could mount the panels parallel to the roof. We used Fast-Jacs to get them off the roof because cooler panels produce more electricity. Daniel and Mark Jakubisin mounted them directly into the trusses before the roof shingles went on. (The roofers had more work, but they're better at putting on the flashing than we would have been.)
The panels have DC power cords built in. They snap together like Lego (tm) pieces. I hooked up 7 in series for the left array and 7 in series for the right array, and measured around 265 VDC for both. The two positives go into a fuse and get combined for the same voltage and the combined amperage.
About the Fronius: it senses the sine wave of the Duke Energy line in order to figure out if it should sent out power.
Of course it has to be in phase with that incoming power to work right. Also, if it senses that there is no incoming power, then it will cut off AC output (because otherwise there could be a Duke lineman working on an energized line). If there is an interruption of Duke power, it will not deliver AC power until the power has been re-established for ten minutes.
Our electrical inspector had us move the DC disconnect to the attic, and an "accessible" place. This meant placing it above the attic access. He also had us put a galvanized "hard pipe" through the roof, and a weatherhead on top of it. These were readily available at Lowes. We used flexible ("smurf") conduit to get it from a junction box next to the combiner over to the DC disconnect.
Make sure that the inspector indicates that he inspected the solar system on the form that you get from Duke.
Notes on NC Greenpower
I dealt with Sunny (what a great name for someone working in renewable energy!). I signed contracts saying that I would sell my RECs to them and them only. She sent me a sheet of return addresses and I will send her my Duke Energy bills once I start producing. I can also fax it in.
Notes on Duke Energy
I went with a dual meter can, at Dave Cook's suggestion (more on Dave in a minute) because it looks a lot better on the outside and the schematic would not need to be overhauled. See my other post for why I went with dual metering. I had to get John to put a second wire out to the second meter, because the Fronius is putting out +120 VAC and -120 VAC in phase (to make it +/- 240 VAC).
They have a checklist which describes the $100 application fee and the documents they need. They also wanted a copy of my homeowner's insurance declarations page.
Strange as it may seem, I had to register with the North Carolina Utilities Commission and also with Federal Energy Regulatory Commission. They take their power seriously. (These sites were also on the checklist.) If you don't have an electrical engineer handy to answer these questions, you are not a co-generational facility
I had some extended conversations with Beth H. and Steve Smith at Duke. They really helped me think about the options (dual metering versus bi-directional, and Option A versus Option B). I created a spreadsheet to estimate how much each of the four options would reap, and went with dual metering, option B. Steve confirmed that this was the combination that most people used at my size of array (3.1 kW). (I believe that they are not allowed to advise and recommend.) They were very patient in correct my spreadsheet errors, some of which were typos (like .000239 instead of .00239) and some of which were misconceptions. For example, they explained that Capacity credits have on-peak and off-peak months, while energy credits follow Time-of-Use and have on-peak and off-peak hours.
The spreadsheet used an estimate of the solar day of 4.7 hours. (This means taking the average number of sunshine hours and reducing by factors such as clouds, haze, pollution, and bird poop.) It also took into account the length of the days at 35 degrees 14 minutes and used that as a proxy for how the 5318 kWH would be distributed over the year, by month. It also made a really rough guess as to how many Energy hours would be on-peak and off peak: 26% on peak in the winter and 37% on peak in the summer. Here's my reasoning: the average length of day in June through September is 13.5 hours. About 7 of those hours are during on-peak hours. But two of those days each week are on the weekend. So I'm thinking 35 hours / (7 * 13.5) = 37%. Average days in the winter are 11.24 hours long. On peak is from 8 AM to 1 PM, so that would be about 5 hours a day.
An engineer, Dave Cook, dropped by today to take some pictures of the solar panels and to get a picture of the boiler plate of the Fronius. There still is some question as to whether we will need to add an AC disconnect on the outside, between his meter and the Fronius. NC Utilities thinks it is unnecessary, but Duke Energy wants to protect its employees. My take on it is that the Fronius will disconnect itself if there is no power. However, Dave's point is that if I shorted the wire in the house, there would be no cutoff between the short and the transformer. Great for my Fronius, but bad for the Duke equipment. He put a cutoff sign outside the house near the utility access point.
Financial considerations
North Carolina will give you a tax credit for 35%, up to $10,400.
I waited until after January 1, 2009 to put the solar panel into service, because the federal tax credit is no longer capped at $2000 for the 30%.
Charlotte Mecklenburg is offering up to 25% off on houses that get LEED certified. I may have waited too long for this, because I needed to have applied BEFORE I got my CO. As of today, the web site does not show anyone claiming this money, although there are a number of corporate applications pending.
Time to break even
This is assuming that the RECs will hold steady, which many consider doubtful.
Cost of the array: $18,000. Delivery and Installation: $1000. State tax credits: $6650. Federal tax credits: $5700. Breakeven will be in about 7 years.
The breakeven time for a solar water heater may be even shorter. I have heard that it is 7 years, without taking any tax credits into account.
I will revise these notes as I go along.
Notes on installing the solar panels
Love the folks at Solar Electric Supply. From them, I bought a kit including:
- Solar panels (x14)
- aluminum rails to mount them on
- Fronius inverter
- DC Disconnect
- DC Collector
- AC Disconnect
- wire to get the electricity off the roof
- Fast-Jacs to mount the panels on the roof
- schematics and instructions
We picked them up from the local Roadway trucking distributor in two trips. (That's one of the reasons Charlotte is popular with trucking companies: I-85 and I-77 intersect here.)
We oriented the house so that the long dimension was facing south. The roof angle was close enough to our Longitude of 34 degrees that we could mount the panels parallel to the roof. We used Fast-Jacs to get them off the roof because cooler panels produce more electricity. Daniel and Mark Jakubisin mounted them directly into the trusses before the roof shingles went on. (The roofers had more work, but they're better at putting on the flashing than we would have been.)
The panels have DC power cords built in. They snap together like Lego (tm) pieces. I hooked up 7 in series for the left array and 7 in series for the right array, and measured around 265 VDC for both. The two positives go into a fuse and get combined for the same voltage and the combined amperage.
About the Fronius: it senses the sine wave of the Duke Energy line in order to figure out if it should sent out power.
Of course it has to be in phase with that incoming power to work right. Also, if it senses that there is no incoming power, then it will cut off AC output (because otherwise there could be a Duke lineman working on an energized line). If there is an interruption of Duke power, it will not deliver AC power until the power has been re-established for ten minutes.
Our electrical inspector had us move the DC disconnect to the attic, and an "accessible" place. This meant placing it above the attic access. He also had us put a galvanized "hard pipe" through the roof, and a weatherhead on top of it. These were readily available at Lowes. We used flexible ("smurf") conduit to get it from a junction box next to the combiner over to the DC disconnect.
Make sure that the inspector indicates that he inspected the solar system on the form that you get from Duke.
Notes on NC Greenpower
I dealt with Sunny (what a great name for someone working in renewable energy!). I signed contracts saying that I would sell my RECs to them and them only. She sent me a sheet of return addresses and I will send her my Duke Energy bills once I start producing. I can also fax it in.
Notes on Duke Energy
I went with a dual meter can, at Dave Cook's suggestion (more on Dave in a minute) because it looks a lot better on the outside and the schematic would not need to be overhauled. See my other post for why I went with dual metering. I had to get John to put a second wire out to the second meter, because the Fronius is putting out +120 VAC and -120 VAC in phase (to make it +/- 240 VAC).
They have a checklist which describes the $100 application fee and the documents they need. They also wanted a copy of my homeowner's insurance declarations page.
Strange as it may seem, I had to register with the North Carolina Utilities Commission and also with Federal Energy Regulatory Commission. They take their power seriously. (These sites were also on the checklist.) If you don't have an electrical engineer handy to answer these questions, you are not a co-generational facility
I had some extended conversations with Beth H. and Steve Smith at Duke. They really helped me think about the options (dual metering versus bi-directional, and Option A versus Option B). I created a spreadsheet to estimate how much each of the four options would reap, and went with dual metering, option B. Steve confirmed that this was the combination that most people used at my size of array (3.1 kW). (I believe that they are not allowed to advise and recommend.) They were very patient in correct my spreadsheet errors, some of which were typos (like .000239 instead of .00239) and some of which were misconceptions. For example, they explained that Capacity credits have on-peak and off-peak months, while energy credits follow Time-of-Use and have on-peak and off-peak hours.
The spreadsheet used an estimate of the solar day of 4.7 hours. (This means taking the average number of sunshine hours and reducing by factors such as clouds, haze, pollution, and bird poop.) It also took into account the length of the days at 35 degrees 14 minutes and used that as a proxy for how the 5318 kWH would be distributed over the year, by month. It also made a really rough guess as to how many Energy hours would be on-peak and off peak: 26% on peak in the winter and 37% on peak in the summer. Here's my reasoning: the average length of day in June through September is 13.5 hours. About 7 of those hours are during on-peak hours. But two of those days each week are on the weekend. So I'm thinking 35 hours / (7 * 13.5) = 37%. Average days in the winter are 11.24 hours long. On peak is from 8 AM to 1 PM, so that would be about 5 hours a day.
An engineer, Dave Cook, dropped by today to take some pictures of the solar panels and to get a picture of the boiler plate of the Fronius. There still is some question as to whether we will need to add an AC disconnect on the outside, between his meter and the Fronius. NC Utilities thinks it is unnecessary, but Duke Energy wants to protect its employees. My take on it is that the Fronius will disconnect itself if there is no power. However, Dave's point is that if I shorted the wire in the house, there would be no cutoff between the short and the transformer. Great for my Fronius, but bad for the Duke equipment. He put a cutoff sign outside the house near the utility access point.
Financial considerations
North Carolina will give you a tax credit for 35%, up to $10,400.
I waited until after January 1, 2009 to put the solar panel into service, because the federal tax credit is no longer capped at $2000 for the 30%.
Charlotte Mecklenburg is offering up to 25% off on houses that get LEED certified. I may have waited too long for this, because I needed to have applied BEFORE I got my CO. As of today, the web site does not show anyone claiming this money, although there are a number of corporate applications pending.
Time to break even
This is assuming that the RECs will hold steady, which many consider doubtful.
Cost of the array: $18,000. Delivery and Installation: $1000. State tax credits: $6650. Federal tax credits: $5700. Breakeven will be in about 7 years.
The breakeven time for a solar water heater may be even shorter. I have heard that it is 7 years, without taking any tax credits into account.
Moved in, got the CO, solar panel breakeven
We moved in Friday, Dec 12, based on a temporary certificate of occupancy.
Thanks to the best friends in Charlotte! People in our church and from Karen's homeschooling group helped move every scrap of furniture, from small lamps to a heavy piano, as well as everything we had in storage.
We got our final on electrical on Jan 20, and got our Certificate of Occupancy later that day.
I talked to the patient people at Duke Energy about connecting the solar panels. I finally understand that I can sell two different parts of what is coming off the panels. I can sell electricity, measured in kWH and green credits, measured in Renewable Energy Credits.
All this time I thought I was just selling electricity.
The first question on anyone's lips is: how much will you get?
The answer: it varies. Read carefully, Grasshopper.
Now the electricity can be sold in two different flavors: Option A and Option B. It can be sold using either a bi-directional meter (costs $3.75 a month to administer) or with dual meters ($16.20 a month).
Steve Smith from Duke Energy put a lot of effort into drawing this picture of the different metering options.
I created a spreadsheet to compare the options. Between bi-directional and dual metering, dual metering comes out way ahead. If you look at Steve's picture, you'll see that bi-directional gets you credit for the intervals that you are sending back more power than you are consuming, while dual metering does a "buy all/sell all," i.e., buys all of my residential electricity from Duke and sells all of my rooftop electricity to Duke. It also gets me more RECs.
Now there is one site that calls RECs bragging rights. This allows me to salve the conscience of Al Gore and other environmentalists so that they can say they are using clean energy when, in fact, they are burning bituminous coal to make their electricity and burning gasoline to power their cars.
OK, I can see that you're still waiting to find out how much I am going to get for these solar panels. Here ya go, Grasshopper.
Duke will pay me these rates for kilowatt-hours. The number are in pennies. So the first option pays $0.0239 / kWH.
So the energy I put on the grid varies on the month (June-Sep are peak months) and by the hour (for example, 1PM to 9PM in the summer months are peak hours). Duke will also pay more for the energy I put on the grid (Energy credit) as well as for power plants that they won't have to build (Capacity credit).
Steve says a handy rule-of-thumb is 6 cents a kWH for Option B. He also mentioned that most of his customers are using Option B.
NC Greenpower will be selling my RECs for 15 cents a kWH.
And the second question is usually: "How long until you break even?" That answer will depend on the kindness of NC Greenpower to continue paying out their RECs. When my contract is up, they could raise or lower (more likely lower) the amount they pay for RECs. I suppose that I could try to sell them on eBay?
Thanks to the best friends in Charlotte! People in our church and from Karen's homeschooling group helped move every scrap of furniture, from small lamps to a heavy piano, as well as everything we had in storage.
We got our final on electrical on Jan 20, and got our Certificate of Occupancy later that day.
I talked to the patient people at Duke Energy about connecting the solar panels. I finally understand that I can sell two different parts of what is coming off the panels. I can sell electricity, measured in kWH and green credits, measured in Renewable Energy Credits.
All this time I thought I was just selling electricity.
The first question on anyone's lips is: how much will you get?
The answer: it varies. Read carefully, Grasshopper.
Now the electricity can be sold in two different flavors: Option A and Option B. It can be sold using either a bi-directional meter (costs $3.75 a month to administer) or with dual meters ($16.20 a month).
Steve Smith from Duke Energy put a lot of effort into drawing this picture of the different metering options.
I created a spreadsheet to compare the options. Between bi-directional and dual metering, dual metering comes out way ahead. If you look at Steve's picture, you'll see that bi-directional gets you credit for the intervals that you are sending back more power than you are consuming, while dual metering does a "buy all/sell all," i.e., buys all of my residential electricity from Duke and sells all of my rooftop electricity to Duke. It also gets me more RECs.
Now there is one site that calls RECs bragging rights. This allows me to salve the conscience of Al Gore and other environmentalists so that they can say they are using clean energy when, in fact, they are burning bituminous coal to make their electricity and burning gasoline to power their cars.
OK, I can see that you're still waiting to find out how much I am going to get for these solar panels. Here ya go, Grasshopper.
Duke will pay me these rates for kilowatt-hours. The number are in pennies. So the first option pays $0.0239 / kWH.
- Option A Capacity Credit on peak 2.39
- Option A Capacity Credit off peak 0.47
- Option A Energy credit on peak 5.34
- Option A Energy credit off peak 3.87
- Option B Capacity Credit on peak 8.40
- Option B Capacity Credit off peak 1.30
- Option B Energy credit on peak 5.64
- Option B Energy credit off peak 4.28
So the energy I put on the grid varies on the month (June-Sep are peak months) and by the hour (for example, 1PM to 9PM in the summer months are peak hours). Duke will also pay more for the energy I put on the grid (Energy credit) as well as for power plants that they won't have to build (Capacity credit).
Steve says a handy rule-of-thumb is 6 cents a kWH for Option B. He also mentioned that most of his customers are using Option B.
NC Greenpower will be selling my RECs for 15 cents a kWH.
And the second question is usually: "How long until you break even?" That answer will depend on the kindness of NC Greenpower to continue paying out their RECs. When my contract is up, they could raise or lower (more likely lower) the amount they pay for RECs. I suppose that I could try to sell them on eBay?
Tuesday, January 20, 2009
First Snow
We wanted more, but we only received a dusting of snow. But how lovely the snow is in your own home!
Sunday, December 14, 2008
Putting it together...bit by bit
After securing the temporary C.O., the Chacko family moves into their new digs about 10 days before Christmas!Final grading around the house was done after the move. Good thing, too! It was wet and rainy when we moved in and we had tire tracks all over the place. I can't wait until spring when we can get some grass and other plants in!
Friday, December 5, 2008
Finishing touches
It has been a long time since we posted. Although a lot has happened, it seems also to be in slow motion. Two coats of finish have been placed on the floor. It's really looking nice, but the final coat still has to been finished. Closet organizers, shoe molding, appliances, heating/cooling, water heater, screened porches, doors, decorative brackets on the outside, and lighting & switches have all been installed. Of the four final inspections, we have had all four, but only passed two. We will be installing railings on the decks this weekend to finish off the building inspection, and then the last hurdle is electrical. It is our hope to call for the electrical final inspection sometime this coming week. We'll keep you posted. But for now, we are still in our little apartment, sitting amongst boxes and biding our time.
Josiah's closet organizer
The floor in Hannah's room, and
her closet organizer
We hung our own towel racks and paper holders.
Thursday, November 13, 2008
Compass Rose
We've been hard at work, building the decks. Rajah and Josiah and a team of guys from our Care Group at church worked on the back deck together.
The front deck was built by a guy named Jason. Rajah was so proud of the compass rose design that we were able to have built into the front deck. What do you think?
Friday, November 7, 2008
Decks underway...
Plumbing fixtures are finished. I watched them test the water and it flows!
And there is hope that we will be able to have visitors come through our front door! Behold! Stairs!
Jason, a deck builder, has started working on the front. Rajah has asked him to put in a compass rose design on the front porch. After building the stairs, he started the railings.
Rajah and Josiah have been hard at work learning to install the Trex material (harder than it looks). They started on the side deck.
John has begun installing our lights on the first floor. It's looking good!
And what do you think of our fireplace now??
I love the stone! Hope to be ready to receive you as a guest soon!
Wednesday, November 5, 2008
Current status, beginning plumbing fixtures
The plumbing fixtures are going in today. I also met the gutter installers and fireplace stone masons out at the house today. It's all beginning to take shape (finally!).
Here's the faucet in the upstairs kids bathroom, and the toilet.
Here's the kitchen sink faucet and water filter faucet:
and dishwasher...
The fireplace mantle was installed the other day,
and today, they were beginning to prepare to put the stone facade around:
And outside, they poured the concrete parking pad last week. So here's how the outside looks right now:
We're still hoping to get in soon, but we may still face more delays. Keep praying!
Here's the faucet in the upstairs kids bathroom, and the toilet.
Here's the kitchen sink faucet and water filter faucet:
and dishwasher...
The fireplace mantle was installed the other day,
and today, they were beginning to prepare to put the stone facade around:
And outside, they poured the concrete parking pad last week. So here's how the outside looks right now:
We're still hoping to get in soon, but we may still face more delays. Keep praying!
Tuesday, October 28, 2008
T minus 2 1/2 weeks and counting?
Tile is finished. Garage doors are in. Electrical is underway. Plumbers come tomorrow to install dishwasher, disposal, tankless water heater, and plumbing fixtures. I think they started running the gas line that will connect to our house soon (which we need for temporary heat). Come to our deck party and help construct our decks this Saturday!!
Master bath-tub hole. Below, Hannah is trying out the tub that will go there tomorrow.
Completed tile in the guest bathroom.
Garage doors can open manually right now...and soon they will use electricity!
Master bath-tub hole. Below, Hannah is trying out the tub that will go there tomorrow.
Completed tile in the guest bathroom.
Garage doors can open manually right now...and soon they will use electricity!
Friday, October 24, 2008
Tile underway
All areas for tile were started today. Here are some pictures:
Backsplash in the kitchen,
Master bath shower,
Upstairs kids bathroom
and the floor in the downstairs bathroom.
Backsplash in the kitchen,
Master bath shower,
Upstairs kids bathroom
and the floor in the downstairs bathroom.
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