Panel prices have dropped tremendously over the past year. Quotes may differ depending on city, but $3.60/watt sounds too high, especially for the size system you're talking about (their fixed costs are divided over many more watts than the usual residential installation). We just paid $3.35/watt for our 7.5kW system using LG 290 panels, and those panels are more expensive than the 260W panels you were quoted. Note you don't need a more efficient (higher wattage), more expensive panel because it sounds like you have more than enough roof space to get the output you want using 260W panels.
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Thinking of going with this solar installer/proposal. Please comment/critique/discuss
- Thread starter Al Sherman
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- Energy Environment Policy
Panel prices have dropped tremendously over the past year. Quotes may differ depending on city, but $3.60/watt sounds too high, especially for the size system you're talking about (their fixed costs are divided over many more watts than the usual residential installation). We just paid $3.35/watt for our 7.5kW system using LG 290 panels, and those panels are more expensive than the 260W panels you were quoted. Note you don't need a more efficient (higher wattage), more expensive panel because it sounds like you have more than enough roof space to get the output you want using 260W panels.
dhrivnak
Active Member
Last fall we used Sunvia panels and our installed cost was $3.75/watt. So far I have been well pleased.
Yes, our price was $25,343 before any rebates/credits for the entire 7.5kW system installed. We used Solar Edge power optimizers and two inverters. The cost would have been close to $1000 less if we went with SMA inverters instead of Solar Edge. Output is greater than predicted-- 50 kWh two days ago and 44 kWh yesterday.
nwdiver
Well-Known Member
I installed Suniva panels on my house in Oct 2012... so far so good. $3.60/w is a little steep but not terrible. I paid ~$2/w for EVERYTHING except labour... You're going with micro-inverters which tend to cost about twice as much as string inverters so your equipment costs are probably ~$2.3/w. IMO you can probably negotiate down to ~$3/w.
I think the micro inverters explain the difference between me and TexasEV. As far as 3.60 vs 3.00. I just may try to negotiate. Still trying to get the wife on board. She's uptight about covering her roof with panels.
Incidentally, the salesman said he'd give me a written guarantee that they'd produce within 20% of his estimate. However, I've called about 10 of his past installs and they all report getting at least what he predicted or more in my neck of the woods. So maybe negotiating down would be better.
I don't know. My understanding is that the micro inverters are state of the art and much more efficient. I haven't gotten any quotes on the optimizers and centralized inverters so I can't say if the numbers work out one way or the other. This isn't just from this particular salesman. What I'm getting is that in this constantly evolving technology the micro inverters are the current way to go. Most of the installers I got estimates from were very hesitant to quote Optimizers with Centralized inverter. A couple said they wouldn't. Maybe it's just something that gives them more margin and they're all in lock step but I simply don't know. They all seem to think the micro inverters are the new "better" way. You can get an iPhone 4 for free with a 2 year contract. The 5S is 400 bucks.
Think of solar dealers like car dealers. Do your own research, such as at solarpaneltalk.com. My understanding is there isn't a big advantage to microinverters unless you have shade issues on your roof. In full sun the efficiency difference is trivial, more a marketing point than anything real. Have them show you the difference in output for your proposed system using traditional inverters ( would be more than one with your size system) and see if the extra cost of Enphase is worth it.
I have a 3.2kW system on my roof with Enphase microinverters. At the time, it added about 1 year to the break even point over a central inverter, but gave an additional 15 years of warranty and lifetime monitoring. Between that and the per panel monitoring, it seemed like a good deal to me. As for the performance, I was told to expect 3269kWh out of it per year and the first year I got 3900! I'm 10 months into the second year and am already up to 3090, so I should exceed the rated output again. So overall I'm very happy with the Enphase units. Working great with no problems and performing better then expected. The only issue I've noticed is the monitored output it claims to produce is a few percent higher then what I'm actually getting (I have a utility grade meter to get an accurate measurement of output). Several others with my model have noticed this issue too.
At the time, I don't think optimizers were an option with the central inverter. So I'm not sure how they compare.
At the time, I don't think optimizers were an option with the central inverter. So I'm not sure how they compare.
GlennAlanBerry
Member
I think micro inverters are most useful if you have partial shading issues. If you don't have shading, micros inverters are not really necessary.
swaltner
Active Member
Not trying to derail the conversation too much off the solar topic, but since the conservation aspect has been discussed. You mentioned that you suspect the huge power demands are coming from the dual geothermal systems, but the HVAC folks say they are working fine. Data is your friend in situations like this.
I'd suggest a TED system, but there are many options similar to this. TED Pro Home is their new TED Pro Home system, which in conjunction with their Spyder modules can individually monitor the power draw of each circuit in your breaker panel. This will help you track down the power usage in your house. Is the electricity usage being done from things like lights that never get turned off, old refrigerators, your geothermal system, pumps in the swimming pool, etc... With the new Spyder module, it's relatively cost effective to track power usage on up to 32 individual circuits within your house. As mentioned, there are other products that do similar tracking, I'm just familiar with their TED 5000 product line. I have a TED 5003 system installed in my house to track usage on two breaker panels and the EVSE for charging the car.
I'd suggest a TED system, but there are many options similar to this. TED Pro Home is their new TED Pro Home system, which in conjunction with their Spyder modules can individually monitor the power draw of each circuit in your breaker panel. This will help you track down the power usage in your house. Is the electricity usage being done from things like lights that never get turned off, old refrigerators, your geothermal system, pumps in the swimming pool, etc... With the new Spyder module, it's relatively cost effective to track power usage on up to 32 individual circuits within your house. As mentioned, there are other products that do similar tracking, I'm just familiar with their TED 5000 product line. I have a TED 5003 system installed in my house to track usage on two breaker panels and the EVSE for charging the car.
Consider superinsulation.
(Your local insulation contractors almost certainly don't know how to superinsulate. I suggest "The Super-Insulated Retrofit Book" from 1981 as a guide -- but be aware that the standards for hooking up heat recovery ventilators have changed substantially since then.)
Yes, you'll want a home energy audit first. Your house is probably leaky as a sieve, unless it's *extremely* large. It may not be worth it to do full superinsulation if it turns out that your house is actually pretty tight, but I'm sure you can get some major improvements.
Second, switch all your lighting to LEDs if you haven't already. Your lighting load is probably much larger than you think it is.
A quick summary of super-insulation.
People vastly underestimate the benefits which can be gained from proper insulation and air/vapor-sealing. If the entire house is air-sealed, and every surface has a sufficiently high R-value (no large gaps except the windows, where it's impossible to do much better than R-5 ) -- then you can have very low heating and cooling loads. (In general you want a minimum of R-40 on the ceiling, R-12 in the walls, and R-2 on the windows -- which is not usually that hard. Most of the hard work is in doing the air/vapor barrier properly, which has all kinds of tricky issues.) The biggest catch is, if the house is sufficiently air-sealed, you need to install an energy recovery ventilator or heat recovery ventilator to make sure you have sufficient fresh air. It's worth knowing that replacing the windows is generally the most expensive part of superinsulation *and* the least important; the walls, ceiling, basement, and foundation/wall connection are all more important.
I'm sure there's a lot that can be done. But our house IS huge. Way too big for two people and a pack of dogs but what can I say it's where we live. Probably will till the end. I'm ready to pull the trigger on the installation but I'm still waiting on the good doctor. How the house looks is much more important to her than me. She's not sure she can handle the roof covered with panels. She has to agree or we wont do it. I don't want to "torture" her for the rest of her life every time she comes down the driveway. A ground array wont happen either. We live on 40 acres of trees. Any practical spot would involve cutting down a lot of trees which she definitely wont do. Otherwise I'd have a runway.:smile:
RichardC
Cdn Sig & Solar Supporter
Al, I faced some similar challenges, which I managed to overcome with an installation of black on black SunPower panels with black racking (which satisfied concerns about the appearance of the system). Getting some positive feedback from neighbours may also help!
Good luck with the project.
http://us.sunpower.com/homes/products-services/solar-panels/signature-black/
https://www.google.ca/search?q=sunp...s%2Fsolar-panels%2Fsignature-black%2F;410;285
Owner
Active Member
I have never quite understood why some people think solar panels are so unaesthetic on a roof. I heard this comment from someone else with a very tall two story house with a very non descript roof. I doubt anyone looks up on their roof as the approach is from below. Most roofs you pretty much ignore. and I am extremely picky about these things. I even paid PGE to take down some power lines -- for a large chunk of change
GlennAlanBerry
Member
The fact remains that 3900kWh per month in a 2000-3000 square foot house is quite high (on average). Of course, this depends on how old the house is, what climate zone you are in, occupant behavior, etc. It really makes sense to get a subsidized energy audit, to see what you might be able to do to reduce your usage.
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Regardless of whether or not you get the PV system, doing the high priority items that show up on your energy audit should make a pretty big dent in your electrical usage. I would love to hear about what the energy audit shows.
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Regardless of whether or not you get the PV system, doing the high priority items that show up on your energy audit should make a pretty big dent in your electrical usage. I would love to hear about what the energy audit shows.
Sorry. I guess "huge" IS relative. Our house is 10,000 square feet. The energy audit IS scheduled for Monday.
As far as the looks of a roof with panels; what can I say? It's a personal thing. I think a house with solar panels looks good. My wife isn't sure. I had a photoshop mock up made and she's looking at it every day to see how she feels.
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