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Gavin

Well-known member
Joined
Apr 23, 2010
Messages
471
Location
Albuquerque, NM
Ok, so I'm going to add 3.1 kw of solar panels on my roof.

Talking with two companies...

We have a German company that just opened up a factory here in Albuquerque...300 jobs, 100 million invested in new factory...So I would love to support them and put their panels up...

But I haven't heard much about them...Schott Solar...but one company loves them and is giving me a great price...under 6 bucks a watt, installed...

The other company is pushing SunPower...I know they are big in Cali and NY and all...and they are smaller and lighter....but the system is a bit over 7 bucks a watt, installed...

Now that doesn't seem huge, but on a 3kw system the different is 3 thousand bucks.

On top of that one is pushing micro inverters, the other a single large inverter...

the companies seem to know that each other is their main competition (there are other companies, but these two have been doing solar in Albuquerque for over 13 years, so I want to use one or the other)...so they both take subtle digs at the competitions product...

Well actually the cheaper one doesn't so much as they know they are cheaper...the SunPower company is a bit more about how they are better...but then they have to sell it a bit has they are more expensive...

I really would love to hear what people like about their system...and if anybody has any experience with Schott Solar panels (225watt) and with micro-inverters....

Thanks

Gavin
 
I investigated a 5KW system for use on my house (South of Boston), we have terrible "insolation" (# of hours of sun / day of usable energy) in the Northeast, but with the %30 federal tax credit, $5,000 MA State Rebate form our "Commonwealth Solar" program, and the fact that in the Northeast, we can "sell" the SRECs (Solar Renewable Energy Credits), for a net of about .285 per KW produced, it brings the system down to a 10 year payback for me. My problem? I am going to sell this house in the next few years, and downsize, so I just don't see putting $40K into a PV system right now... on the new house, once I move? absolutley...

With all of that said, I have investigated this and researched it a lot, the microinverters are far superior for a few reasons:

If you have any trees, or any nearby buildings that cast any amount of shadow on your PV array, the output drops dramaticly. With Microinverters, only the affected panel(s) output drops, while the rest continue to produce power. With a string inverter, all panels on that string stop producing power, if the voltage dips below the startup voltage of the inverter, you essentialy lose more power production.

panel/invert failure: since each panel has it's own inverter, a single panel or inverter failure won't bring the entire system offline, rather you lose just that one device. With a single inverter, you will lose possible 1/3 or 1/2 of your power production, depending on how many strings in your array

monitoring: I assume you are speaking of "enphase" microinverters. They have a communications gateway that connects to the internet (the inverters talk to it through the AC house wiring), it monitors every panels output in 5 minutes increments, very nice for tracking production, and making sure everything is still working.

MPTT: each panel is run at it's optimum load, for peak power production, in a string, you have to make compromises...

Here is their website for "enpower", their web based tracking system, checkout some systems in your area...

http://enlighten.enphaseenergy.com/all_public_systems

when I get a PV system, it will only be with microinverters, simpler to wire, no central point of failure, and not much (if any) premium over an older single inverter

want to do it yourself? It's possible, but you need to still get the permits and find out about the electrical code requirments in yor town/city.

http://store.solar-electric.com/enmigrsy.html

PVWatts, estimate your solar KW per day based on your area and specific insallation: http://www.pvwatts.org/

Enphase, how it works: http://www.enphaseenergy.com/products/moreinfo/howitworks.cfm

Enphase Product page: http://www.enphaseenergy.com/products/
 
Gavin said:
Ok, so I'm going to add 3.1 kw of solar panels on my roof.

Talking with two companies...

We have a German company that just opened up a factory here in Albuquerque...300 jobs, 100 million invested in new factory...So I would love to support them and put their panels up...

But I haven't heard much about them...Schott Solar...but one company loves them and is giving me a great price...under 6 bucks a watt, installed...

The other company is pushing SunPower...I know they are big in Cali and NY and all...and they are smaller and lighter....but the system is a bit over 7 bucks a watt, installed...

Now that doesn't seem huge, but on a 3kw system the different is 3 thousand bucks.

On top of that one is pushing micro inverters, the other a single large inverter...

the companies seem to know that each other is their main competition (there are other companies, but these two have been doing solar in Albuquerque for over 13 years, so I want to use one or the other)...so they both take subtle digs at the competitions product...

Well actually the cheaper one doesn't so much as they know they are cheaper...the SunPower company is a bit more about how they are better...but then they have to sell it a bit has they are more expensive...

I really would love to hear what people like about their system...and if anybody has any experience with Schott Solar panels (225watt) and with micro-inverters....

Thanks

Gavin
I just got a Sunpower system last month. I love it the panels do output more then others panels. I got a great deal at $5.6
a watt. The price for my 5.16k system was $29,000 -$13,500 from Electric company -$1,000 from state and 30% from Uncle Sam. Make the payoff in about 7years. I do like the micro inverter but Sunpower does not sell them yet. I have a tree late in the day around 6pm that shuts me down. I could get maybe little less then a 1k if I cut the tree down but I cut 1 pine tree down and 1 in half. I not sure if it would be worth it to cut it down as it is only in summer and real late in the day. I am thinking the tree is worth saving. If anyone knows I have been getting around 35k watts a day out of my 5.16k system is that normal or high or low? Thanks
 
garygid said:
35 kWh is good.
garygid how much power do you get at 6pm or if any at 7pm? I know you have a larger system then me. My system facing south and it is getting hotter so my power now is 33.5 to 34. My 5.16k system only puts out max 4500 to 4900 watts at this temperature.
 
Gavin said:
Ok, so I'm going to add 3.1 kw of solar panels on my roof.

Talking with two companies...

We have a German company that just opened up a factory here in Albuquerque...300 jobs, 100 million invested in new factory...So I would love to support them and put their panels up...

But I haven't heard much about them...Schott Solar...but one company loves them and is giving me a great price...under 6 bucks a watt, installed...

The other company is pushing SunPower...I know they are big in Cali and NY and all...and they are smaller and lighter....but the system is a bit over 7 bucks a watt, installed...

Now that doesn't seem huge, but on a 3kw system the different is 3 thousand bucks.

On top of that one is pushing micro inverters, the other a single large inverter...

the companies seem to know that each other is their main competition (there are other companies, but these two have been doing solar in Albuquerque for over 13 years, so I want to use one or the other)...so they both take subtle digs at the competitions product...

Well actually the cheaper one doesn't so much as they know they are cheaper...the SunPower company is a bit more about how they are better...but then they have to sell it a bit has they are more expensive...

I really would love to hear what people like about their system...and if anybody has any experience with Schott Solar panels (225watt) and with micro-inverters....

Thanks

Gavin
Gavin why are you only buying a 3.1k system it is only going to output 2.5k and unless your electric bill is real small I would get a 5.1k system. You live where it is hot is it now in Albuquerque, NM?
 
Gavin,
I have a mixed mode system. I just added about 1kW to my rooftop PV which was previously just 4 strings to an inverter. I love the microinverters (I have Enphase). When I installed my system I added enough racking HW to expand by 50%. The microinverters allow you to do this simply and cheaply. I estimate my extra kW of panels will drive my LEAF about 6k mi/year. The payback for EV-PV now is very good when I compare to buying gas for a 30 mpg car; about 3 years.

As for Sunpower and some of the other installers; it kinda bugs me that they scare homeowners into buying more system than they maybe can afford up front. I have two friends who have just purchased small homes, have young families and can't drop $25k into a rooftop system. The Sunpower rep said they had to buy panels in strings of 6 and insisted they really needed 18 panels to get the most rebate benefit for their buck. They opted out.

Microinverters allow homeowners to add panels of different Wattages and from different manufacturers.
You can grow your system as your budget allows (or as you add EVs to your garage). Yes, you need to get permits and follow the NEC as you do for any significant home project. But if you add the extra balance of system pieces when you start, it's really easy to take advantage of sales on PV (I found 5 discontinued Sanyos for under $500 each).
Anyway, too long-winded here; Microinverters +1.
 
35KwH per day is a good amount of power from a 5KW PV system, that just shows you have more "power producing" hours / day than we do out east. We have rain, clouds, winter, and crappy weather in general. for the year 3.5-4 hours of production / day on average is about what we can expect out east... peak power only from 11AM to 1PM, yes, from 9AM to 3PM power is produced, but it is either increasing or decreasing during those times... you can check a typical enphase system located in Boston, and see we are just not ideal for PV

This system is in Waltham, MA, (27) 210 W panels (5.67KW system) I believe, 30 day May average was 31kWh/day this month (891.9kWh/29 days so far), which was very sunny, typically its not nearly as much in late fall, winter, early spring here..

http://enlighten.enphaseenergy.com/public/systems/84ss2136

make me sad sort of, and thinking about building my retirement home in Meadview, Arizona sooner, than later :)

Here is a (30) panel system (210 watts/panel? can't tell really), maybe a 6.3KW system, this months 1.2MWh / 29 days, 41.3Kwh/day, not that much larger a system (3 panels), just a different location Phoenix, AZ... just shows how much location affects the power production. as they say, there are only 3 things in real estate, location, location, and location :)

http://enlighten.enphaseenergy.com/public/systems/Hqas1275

BTW, if you check these links during daylight hours, you can see actual power production per panel, in watts..
 
I got a 6.5kW system three and a half years ago. At the time I had not heard of microinverters, if they even existed, so I have two Fronius inverters. There is a group of very tall pine trees southwest of us, near our property. In the fall and winter, when the sun is low in the sky, the shadow of those pines crosses our roof. I can see the output of one inverter drop, then the other fifteen minutes later. An hour or so after that the first one recovers, followed by the second.

Total output: 39,122 kWh in 178 weeks
Average: 220 kWh/week
Minimum: 53 kWh/week (early Jan 2008, lots of rain, no sun all week)
Maximum: 372 kWh/week

On sunny days my system shuts down just a few minutes after sunset unless there are high clouds over the mountains to the west of us. On rainy or total overcast days it shuts down up to half an hour early. I do have an afternoon disadvantage, especially in the summertime, because our roof faces about 20 degrees east of south.
 
Gonewild said:
My system facing south and it is getting hotter so my power now is 33.5 to 34. My 5.16k system only puts out max 4500 to 4900 watts at this temperature.
Actually, it's the light, not the heat, that matters. Ignoring cloud and rainfall patterns you can expect your highest output in late June and your lowest in late December. Locally, we tend to get more rain in January than December, so my lows come then.

Oh, wait. Snow? I have no idea what effect that has, as we've never seen it here. Where we are, heat is our enemy. Our utility meter runs backward most of the spring (building up to June), but forward much of the summer (due to air conditioning).
 
I get some small production (45 watts now at 7:20 pm PDT) from sunrise (6 am) right down to sundown, even though my roof slope is a bit east of south. Even on overcast days there is some substantial generation.

Hot panels (given the same illumination) produce less than cool panels. So, a cool day after a rain (to clean the air), the clouds part ... and I will get my inverter maximum, 7050 AC watts out (SB 7000US inverter).

Today, with 33 x 225 watt Sharp panels in 3 strings of 11, I hit 7000 a few times, but light clouds or variable overcast caused many "drops" to half that.

Total production today was 44 kWh, and a totally clear day can be better.
 
This shows the insolation for various cities across US. You have a low of 3.1 in Chicago to a high of 6.7 in Albuquerque among bigger cities. This is the average in a year.

http://www.solar4power.com/solar-power-insolation-window.html
 
nice deal on a little over a 5KW Enphase system with (24) Sharp 224W panels...

http://www.wholesalesolar.com/system/5376-sharp-enphase-grid-tie-solar-power-system.html

they forgot 1 of the "Enphase Install Kit, AC Branch Circuit", you can only put 14 microinverters per 15A 2-pole circut (what they recomend), and I would think the Energy Management Unit and monitoring is also required.. very inexpensive though @
$3.69/watt, of course you still need the electrician, permit, a little bit of wiring and a couple 2 pole 15A breakers, but it's not much.

You also need the racking, which is gonna add about $1700 to the price as well.
 
Gonewild, That is a very good price you got for installed Solar. Can you please tell me what company you used so I can see if they are in the SF bay area and give such great prices?
 
Gavin[/quote]
Gavin why are you only buying a 3.1k system it is only going to output 2.5k and unless your electric bill is real small I would get a 5.1k system. You live where it is hot is it now in Albuquerque, NM?[/quote]

A variety of reasons...

1. Cost...going to be buying a 32k car this winter :)...have a daughter in out of state college...just put a pool in last summer...so spending 18k is easier than spending 30k right now.

2. Roof...And shade. We are in a old established area of albuquerque. The area of our roof that gets no, to very little shade fits 14 to 16 panels...any more will not work as well for the money spent. Now those 14 panels get really good, hard sun, so they should do a good job making power.

3. Usage....we average a litle less than 700kw a month in electricity. A 3.1k solar system will provide about 60% of our usage (we get a lot of sun and at 6000 feet, well we have hard sun with little humidity or any haze blocking solar production.) With the local electric company incentives, 60% covers your bill...and the still pay for every watt you produce...so I see a benefit of 1300 a year--about 650 in reduced electric bill, plus 700 or so in actual payments from pnm...

The system will pay for itself in about 7 years or so...and a larger one who probably pay for itself almost as fast, but I don't want to go home loan or anything like that, and I don't have more roof to throw more panels up anyways...I cut a tree down, but it is a large 50 year old tree that I really don't want to remove...and it on give a bit of shade on the roof anyways...the other side gets some late shade from a different tree, but that is in the neighbors yard, so cutting that down could cause me some problems :)

Gavin
 
thimel said:
Gonewild, That is a very good price you got for installed Solar. Can you please tell me what company you used so I can see if they are in the SF bay area and give such great prices?


I agree...the local sun power dealer (I think we only have one), is about 7 buck a watt installed...they will do micro inverters if I insist, but that will add 1500 to the bill.

The other non sun power dealer is just at 6 bucks a watt installed...with micro inverters.

So a 3.1k sun power is 3 to 4.5k more expensive.

The panels are nice, but hard to spend that much more for about the same power.

That said, anybody familiar with schott solar panels?

I wonder if the Chandler company would travel out here?

Panels actually do better in Albuquerque than phoenix...we aren't nearly as hot in the summer (usually 20 degrees at least cooler). And we are 4000 ft higher, so thinner air. But usually just as many sunny days and our sun length of day is similar.

Gavin
 
ah, schott solar is used mostly in larger commercial jobs, they make some very large industrial panels, they where from Germany originally, but they have a plant in New Mexico now... They used to actually be in Waltham, MA years ago..

We have a building in my town with a 44KW PV system that was done with SCHOTT Solar panels, connected to large inverters, 3 phase, I think the system was in the millions at the time..

http://www.us.schott.com/photovoltaic/english/index.html

SCHOTT Solar PV, Inc.
5201 Hawking Drive, SE
Albuquerque, NM 87106
USA 800 977 0777 / 408 224-2904

Here's a nice google search for you:
http://www.google.com/#hl=en&source=hp&q=schott+solar&btnG=Google+Search&rlz=1R2GGLJ_en&aq=f&aqi=&aql=&oq=&gs_rfai=&fp=dc6c33e694518ee8
 
Yeah, I know a bit about schott as they opened a factory here...so I like the idea of using them and helping local jobs...just wondering if anybody has them on their homes, or have heard good vs bad things

Gavin
 
Not that I know of, but I know they have been in business for a long time, and they where mostly in the commercal PV market.

I also have run into this "sunrun" solar financing site, my guess is they are selling/keeping the "SRECs", and that is how they are making money long term, interesting though, keep the price down on the solar installation for the homeowner.

http://www.sunrunhome.com/why-sunrun/compare-sunrun-solar-options/sunrun-availability

They have 2 plans:

http://www.sunrunhome.com/why-sunrun/compare-sunrun-solar-plans/sunrun-power-plan

and

http://www.sunrunhome.com/why-sunrun/compare-sunrun-solar-plans/sunrun-total-solar
 
mitch672 said:
35KwH per day is a good amount of power from a 5KW PV system, that just shows you have more "power producing" hours / day than we do out east. We have rain, clouds, winter, and crappy weather in general. for the year 3.5-4 hours of production / day on average is about what we can expect out east... peak power only from 11AM to 1PM, yes, from 9AM to 3PM power is produced, but it is either increasing or decreasing during those times... you can check a typical enphase system located in Boston, and see we are just not ideal for PV

This system is in Waltham, MA, (27) 210 W panels (5.67KW system) I believe, 30 day May average was 31kWh/day this month (891.9kWh/29 days so far), which was very sunny, typically its not nearly as much in late fall, winter, early spring here..

http://enlighten.enphaseenergy.com/public/systems/84ss2136

make me sad sort of, and thinking about building my retirement home in Meadview, Arizona sooner, than later :)

Here is a (30) panel system (210 watts/panel? can't tell really), maybe a 6.3KW system, this months 1.2MWh / 29 days, 41.3Kwh/day, not that much larger a system (3 panels), just a different location Phoenix, AZ... just shows how much location affects the power production. as they say, there are only 3 things in real estate, location, location, and location :)

http://enlighten.enphaseenergy.com/public/systems/Hqas1275

BTW, if you check these links during daylight hours, you can see actual power production per panel, in watts..

Our 5.28 kW array produced 653 kWh (average 21.77 per day) for the month of April 2010. We are located south of Boston.
 
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