Eastern NC Solar

Financial update

2010-04-09T13:57:00.000-07:00

1. We are starting to see credit on our utility bill. The one that arrived today credits us 21.06

2. We have received our federal tax refund and therefore have 30% of our expense back already.

Utility Company data

2010-02-05T06:53:00.000-08:00

I am going to try and paste images of an email I got from the local electric company that details energy generated. Click for larger if you wish.

QA3

2010-01-19T06:29:00.000-08:00

Q
Hi guys,
Congratulations on your startup. Interesting monitoring site with neat data presentation.
What do you estimate the annual kwh production of this array ?? Take care
Thanks

A
We asked for a system that would produce what we were currently using. We forwarded utility records to our installer and he told us this was the size system we would need. I went back in the blog to look at records and for the previous year we used 7984 kwh, 665/month, or 21.87 per day on average. So that is what we expect to produce over the course of the year.

Discussion
We expect more light in the summer but the panels will be less efficient due to warmer temperatures. So as time goes on we hope to see increased production just at lower numbers. Our panels are 215 watt rated, so that would be the maximum number we could see on the monitoring site. For efficiency sake, if we see 188, that means that panel is converting 87% of maximum. We also expect we are using more energy with the garage addition.

The reason we went with this size system rather than the breakeven point that a smaller system offered was we wanted to be able to convert to net metering without any subsidy like payout down the road and still make all we need. With selling the renewable energy credits we will make an extra seven cents per kwh, not sure how long this will stay around.

Usage vs production

2010-01-18T09:54:00.000-08:00

My off the cuff calculations suggest that over 10 days we averaged just over 20kwh production per day. Our most recent utility bill suggests we used 33 kwh per day. Hmm!

QA2

2010-01-14T03:37:00.000-08:00

sounds interesting...I have so many questions. cost to install and maintain, durability and life after install, how many days can you go without sunlight. does it store energy for a rainy day...hahahaha

Cost to install: Both my father and I found systems to be about 7K per kwh, ours is a 5.16 kwh system. It gets a little cheaper as you get larger. If this industry grows hopefully prices will come down.

Maintain: I do not know yet but do not expect to spend anything unless a panel goes bad. I recall them being tested for good 25 year life or better. With my system I have more parts, but they are smaller and if something goes bad the replacement should be cheaper (this refers to my microinverters compared to my fathers). The system I have does have a $2 per panel per year fee for the internet interface, so $48 per year to have the enphase link work.

Without sunlight? No problem as we have two meters. We still pay local utility normally, sell ours through the other meter. In the end, we should make money at this, my rough estimate is 10% return each year.

Electrical storage? We did not install a battery backup system. This would allow us to live off grid but would add five thousand to the system cost and require more maintence.

A note on system cost: NC offers 35% tax rebate on system costs, maximum is $10,500. Federal government offers 30% tax credit, no limit. So while we had to get a bank note to pay for this up front, we will only be responsible for about 35% of the system costs. With the payments for energy generated, most systems will pay for themselves in 5-10 years.

See link at topleft for my father sharing his solar experiences pittsolar.blogspot.com

QA

2010-01-13T17:32:00.001-08:00

From a friend:
Congratulations on the successful solar project. It was a good reminder to check in on your blog. That new site is cool, too.

I meant to ask a few questions earlier but I'll ask now.

1. What sort of bracket holds the panels on and is it just nailed screwed through the shingles into the roof with some patch or rubber seal around the hole?

2. In 20, 30, 50 years when the roof needs replacing, do the panels come down for that and then go back up? Does the installer do that or the roofer or Joe's nephew?

3. Does having solar panels on the southern roof affect the passive solar qualities of the building (does it make a building hotter or colder and would it depend on the type and color of roof)?

Congratulations again.

1. Our brackets are roof mounted prior to the shingles. It lifts the panels off about 6 inches. The distance should help with cooling airflow in the summer, a good thing since panels run more efficient when cooler.

2. The panels and racking material come off the roof for roof work. Likely extends a reroofing job by a week or so. Hopefully a solar company does this.

3. Solar panels should make the building cooler as they are the object that receives the heat. The shingles beneath them should be in the shade and cooler. As a side note, we went with light colored shingles to enhance the new building looking like our house and also to keep the panels cooler.

Production

2010-01-13T05:02:00.000-08:00

We have been producing for about a week now. We have produced around 100kwh that the in house monitor has picked up though it likely is more due to early technical difficulties. Today is expected to be nice and clear. We hope to outproduce our best day of 28.8 kwh. The enphase website does not yet have us on their reference installations list, it seems like they might have a minimum kwh total to list, today should get us to that point. We will post a link when that happens.

Edited update: See links at left. Visit the enlighten one to see near real time production and history.

What I see

2010-01-09T09:49:00.001-08:00

Click image for larger version. Bottom right is the enphase unit, I think it is close to "real time". Bottom row of numbers indicates what is being made now, total since power on, and number of solar modules being read.

Sunrise!

2010-01-09T05:08:00.000-08:00

Yesterdays generating total might be a little low as I changed outlets in the morning. So far it appears that we have generated 381W this am, all panels up and running though at low production. The inhouse monitoring unit, aka Envoy, gives data prior to the website. I think it sends data over net at regular intervals.

This is exciting.

LIVE 18kwh today

2010-01-08T15:18:00.000-08:00

We went live on Tuesday as the sun was going down. The picture shows the final connection being made so the switches could be turned on. Since then it has been interesting to see just how much there is yet to learn. The meters are set up to be read early each am by some kind of a silent phone call. I've heard of one company called Badger Meter that does this with cell phones, I think ours are tied into the landlines here, requiring DSL internet filters. Then it took a few days to recognize that our monitoring unit was not working well as it was plugged into an outlet that was on the same breaker circuit as most of the computer gadgets are in, as these are in a surge protector the signal did not make it to the monitor. These signals get transmitted via the neutral/ground wire. We had some loud background noise on our telephone, at least for tonight it has gone away.

Our home monitoring unit relays data via broadband connection to the Enphase Enlighten web site. I've set ours up to be available for the public to see. It is not yet listed but I expect it will be in the coming days. When it is I'll try and post a link. If you follow the following link you can view reference installations of others.

https://enlighten.enphaseenergy.com/systemslist

Time to go live

2010-01-05T03:21:00.001-08:00

We have been told that the local utility has received the interconnection agreement and that we can now go live as a generator. We expect this to happen at 3 pm today. I think this should be a simple task with flipping a few switches and installing two fuses. I will likely activate the monitoring unit before then.

Sunshine

2009-12-30T07:16:00.000-08:00

Pic is of similar view after trees were cut down. We will likely get the system turned on once our local utility receives the interconnection agreement from their electric provider.

Here comes the Sun

2009-12-22T06:54:00.000-08:00

When we started this we thought our location was ideal with no shade areas. At least in winter we now see that we will lose out on generating capacity. We are having a lot of trees removed starting today. We would have preferred to have done this prior to building but the crew could not get here fast enough. They look like they know a bit of what they are doing, should leave the building intact. This is a before photo.

All I want for christmas

2009-12-21T12:13:00.000-08:00

We think all that is left to do is to have local inspector for final on the solar work and then for power to be turned on. It sure looks like we could flip the switch on our own. Our local utility requires some kind of an agreement from their power supplier to buy power from us also. We have full use of our garage and are grateful to our builder for the incredibly fast and efficient work.

If you have not yet, check out my father's blog about his solar PV system here: http://pittsolar.blogspot.com/ He is all set to flip the switch also.

An Examination of the Regional Supply and Demand Balance for Renewable Electricity in the United States through 2015

2009-12-08T09:13:00.000-08:00

51 page pdf here
http://www.nrel.gov/docs/fy09osti/45041.pdf

2009-12-08T06:59:00.000-08:00

Most of the panels are on. Two more have to be put up after the connections are brought through the roof. Rumor is we will get either a final solar or building inspection. Then we get in touch with the local utility for the connections to be made. Our builder suggests that since our utility purchases electricity from Progress Energy, they have to get their "permission" to buy what we generate. Once that is done they can make the connection and we can go live.

We have received our owners manual from Alternative Energy, it has a lot of information on the products being used and the users guide for our monitoring system. This system will require a regular net connection that I will have to figure out as I only have one connection. It is also located close to most of the electronics in the house, the monitoring unit suggests keeping it away from such things.

Solar calculator

2009-12-02T01:04:00.000-08:00

We have some more hardware on the roof, no panels noted but it was dark when I checked last night. I've checked the local weather to guess the likelihood of continued work today. Our favorite site for this is Wunderground. I noted today they have a solar calculator. If the link does not work the calculator is along the left hand side of the site.

http://www.wunderground.com/calculators/solar.html

Solar Calculator
Calculate the amount of clean electricity you can generate from the Sun!
See How Much Insolation You Get

For this location and configuration, you will get about 5 kWhr/m2/day of energy from the sun.

The following is a breakdown of energy by month:

Energy generated per month (in KWhr/m2)

Average daily energy by month (in kWhr/m2/day) 126

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
United States data provided by the NREL. International data is courtesy of NASA.

A new week

2009-11-29T14:39:00.000-08:00

Joe from Alternative Energy called on Friday, said they expected full shipment of our stuff this past Saturday. He expects the crew to install on Monday 11/30/2009. There is threat of some rain, but perhaps we will go live this week.

For now we wait

2009-11-25T17:16:00.000-08:00

Nearly everything is done with the garage. Lights are on! It looks like all of the solar rough work is done. Inside the garage wires and conduit run to the house and up to the roof where they will likely go through and meet with panels. I was told that out panels were being delivered today. At some point in the (hopefully near) future we should get some racks, panels, and inverters set up. Stay tuned.

View of roof this am

2009-11-23T04:57:00.001-08:00

Inverter system

2009-11-23T02:30:00.000-08:00

More rain expected today. All of the brackets are mounted on the roof. Garage siding is done, doors go on Tuesday. I am not sure what the week will bring, should be interesting.

The following looks like the website for the company that makes our expected inverter. They have some neat stuff, a couple cool videos to learn the basics of how the products work. I think we were told that the monitoring system is free for the first two years, then $2 per solar panel per year after that, so $48 per year for us. I think there are a few other options for monitoring, if I recall correctly one was a several thousand dollar option that we did not want to pay for.

http://www.enphaseenergy.com/

Rain Delay

2009-11-19T06:35:00.000-08:00

Lots of rain is keeping folks off the roof. We did get some shingles and brackets installed, but not many. The interesting development yesterday concerned our inverter. The inverter changes the generated energy into a form that can be used on the electric grid. I guess several companies make inverters, I think they function in two different manners. One of them has all the solar panels connected to it and it does the job for all of them. The second is a mini-inverter connected to each panel to do the conversion. The mini-inverter system allows for easier expansion as regular inverters are sized to the size of the kwh (in our case 5.16). There is another key difference, apparently the inverters work at the minimum level of effeciency of each panel or array of panels. For example, our system was originally going to be two 12 panel arrays. If one arrangement had a few panels in the shade or one panel that worked at 80% efficiency, the inverter would only work at the level of energy generated by the shady panels or the 80% panel. With the mini-inverter system, this is not a problem, as each panel has its own inverter allowing it to generate energy as able.

When Joe with Alt Energy was giving us our owners manuals, I started asking more questions about how our inverter would work. I did not realize that the mini-inverters were an option. Now that they are available for us, it is what we are going to go with. I believe they will cost a little more for the parts, but the installation is easier and cheaper. Ceteris paribus, price should work out to be the same. There might also be an added benefit. The system will come with some kind of a computer gadget that will allow remote monitoring. I look forward to learning and playing around with this.

Starting the install

2009-11-18T07:53:00.000-08:00

Picture is of Joe From Alt Energy laying out the brackets. We've asked him to put brackets on the whole roof to allow for expansion in the future. We also got the following info via email today!

Your application to become a solar generator for NC GreenPower has been received and accepted. In the next couple of weeks I will mail a five-year agreement for up to 7300 kWh/year at 15 cents/kWh to you at the address entered in your application. Please check the other information in the application for accuracy, as I will be using this data in the agreement. If you have any questions, please contact me.

Thank you for your interest in NC GreenPower.

Best regards,

Administrative Coordinator
NC GreenPower

Big day coming up

2009-11-17T11:52:00.000-08:00

Someone suggested I point out the the direction our system is facing is unique to our locale, check with your installer to properly face yours. The way things are going around here we will go live next week! The view shown in the pic is where the system will be. It currently gets some shade, we will need to cut some trees down.

Solar work starts this Wednesday!

2009-11-16T08:06:00.000-08:00

The roof should be on in the next couple of days. On Wednesday the solar crew should be here for some rough work. On the roof they will put the brackets in place prior to the roofer doing his work.

Type of system and placement

2009-11-13T07:40:00.000-08:00

In setting up a garage to install solar photovoltaic system upon, we wanted to know the construction requirements. This included how to face the building, what roof angle would be best, and how much roof space would be required. The roof space question is important to consider with regards to going with a traditional solar panel or a newer technology known as thin panel. Thin panel solar uses an even roof surface like metal and uses this to roll out a thin film of solar "panels". I pictured this being like a roll of tin foil spread out everywhere on the roof. We asked our planned installer these questions, following is his reply.

I have attached the quotes we spoke about on Friday. Your average kWh usage over the given 13 month period is 662 kWh/month. A 5 kW PV system would JUST cover that. You may want to consider a slightly larger system. I have utilized the buy all/sell all program on your quotes to give you a ‘best case scenario’ for the payback question.

The ideal setup is a large roof area facing TRUE south. To find true south, first find magnetic south and then add an additional 8 degrees. In other words, you want the compass to point to 188 degrees as opposed to 180 degrees. The roof pitch would be between 7/12 and 9/12. There would be no shading issues at all-including surface obstructions such as plumbing vent pipes or chimneys. A 5 kW PV system would consume approximately 450 square feet.

The price to install thin-film versus a rigid module system is about the same. However, you would need twice the roof area. So, for the above example considering a 5 kW PV system, we would need approximately 900 square feet. Also, the roof would need to be a metal roof, not asphalt shingles or clay tile. Lastly, we would need to work with the roofer to ensure the ridge cap is modified to allow for the wires to pass through it. I would recommend the rigid modules.

Also, the price for a traditional inverter versus the micro-inverters is about the same too. However, there is a 4 month wait on the micro-inverters. If you really want to expand in the future, I would recommend the micro-inverters. You can still expand with the traditional inverter setup-you would just have to add another inverter in the future during the expansion. This adds a little more to the expansion cost-about $1,500.

There is a lot of research going into renewable energy systems. I hear lots of ideas almost monthly. However, they are research projects and far from market. I don’t see anything new coming within the next few years. However, there is always the chance that someone will invent something next year. It is really a guess.

The price to convert to net metering from a buy all/sell all set up is calculated at approximately $350.00.

Solar System Size

2009-11-10T07:47:00.000-08:00

For us the choice of system size was easy, others can choose as they wish. We are going to partake in a program offered by NC Green Power. Initially this group appears to be a government subsidy to encourage sustainable energy development.

With our local utility company it appears the only metering choice is a buy all, sell all agreement. We continue to buy from them at current rates of what we were told is twelve cents per kilowatt-hour. We sell what our system produces to them for five cents per kwh, and then receive payment from NC GreenPower in the amount of fifteen cents per kwh. This yields potential profit of 8 cents per kwh. Some people design a solar system large enough to breakeven considering this subsidized price. Our fear is that this potential subsidy could change (it has already decreased in amount at least once), so we wanted to design a system that would supply us with all our current needs and be expandable in the event that electric cars become more popular.

There are some websites that would allow one to figure out the figures on our own, but we just sent Joe Sheffield our electric usage over the past year. He told us based on the following data that we would need a 5kw system.

Units are in KWH

Month Usage Amount Billed
(excluding state taxes)
Nov, 2008 579.00 $ 79.71
Dec, 2008 482.00 $ 67.29
Jan, 2009 679.00 $ 84.79
Feb, 2009 861.00 $ 105.17
Mar, 2009 688.00 $ 85.80
Apr, 2009 545.00 $ 70.80
May, 2009 453.00 $ 64.26
Jun, 2009 435.00 $ 62.06
Jul, 2009 776.00 $ 103.85
Aug, 2009 935.00 $ 123.34
Sep, 2009 1014.00 $ 133.03
Oct, 2009 537.00 $ 74.94
Nov, 2009 385.00 $ 57.50

More on the start

2009-11-09T07:36:00.000-08:00

We have been saving money for a garage, wanted to pay cash for it when it was built, had been hoping to have enough in the next year or so. My father went to a green building open house, saw some neat stuff. He ran into the guy that built our house, Dan Thomas. Dan specializes in insulated concrete forms for the exterior walls, makes them very efficient for heating and cooling in addition to being much quieter. Also at the open house was a home with solar water heating and a solar photovoltaic electric system. My Dad learned that there are all kinds of tax credits for solar. In essence, our state offers a 35% tax rebate up to $10,500, maximum of half of it the first year. The federal government offers 30% tax credit with no maximum.

My father was interested in meeting with the company that handled the solar system so we went also. Joe Sheffield from Alternative Energy Concepts spent several hours meeting with us, came to my house afterwards to discuss site specifics. Our ideal garage would be in a good spot for solar.

In talking this over with our builder, we decided to try and and finance the whole thing now, get as much tax credit ASAP by finishing construction in 2009 and not have to finance 15K.

The beginning

2009-11-05T07:44:00.000-08:00

This is the start of a new blog for me. I intend to share our journey into solar electricity generation. Construction has already begun but I intend to go back in time and talk about the process thus far and then describe our installation, powering up, and actual use experience. Enjoy.