Advice on proposed equipment

[SatManager]

I have received a bid that I believe that I am ready to accept and would like everyones opinion on it: Location is North Las Vegas, Nevada. No Blockage. String Inverters have been looked at and the ones quoted to me were either undersized or oversized except for the sunpower system which I couldn't afford.

19 Mage Solar USA Powertec Plus 250/6 ML
19 Power-One Aurora Micro-0.25-I Micro-Inverters
Power-One CDD Monitoring System
Roof Mounting
All Interconnections and wiring
All Permits, paperwork (HOA, PUC, Utility)
4.75KW
8433 Kwh
$17,580
$3.70 per watt

Gives me 91% of last years usage but that was before I upgraded the attic to R-50 and radiant barrier. May already showed a drop in usage. Nevada is a Net Metering State so I don't want to go too much over my usage. Estimated break-even is 5 years.

My thought process - I am aware that the Power-One micro-inverters only have a 10 year warranty and accept that. I have a hard time believing that anyone is going to be able to support a 25 year warranty anyway. I rather believe in a bigger company like Power-One now that they are being bought out by ABB will be around in five or ten years. I was also offered the Enphase micro-inverters at the same cost with nearly the same performance. Believe it or not, I liked the monitoring system with the Power-One better than the Enphase Envoy.

So let me know what you think. Give me the bad, the good, the "are you crazy!".

[Ian S]

I have received a bid that I believe that I am ready to accept and would like everyones opinion on it: Location is North Las Vegas, Nevada. No Blockage. String Inverters have been looked at and the ones quoted to me were either undersized or oversized except for the sunpower system which I couldn't afford.

19 Mage Solar USA Powertec Plus 250/6 ML
19 Power-One Aurora Micro-0.25-I Micro-Inverters
Power-One CDD Monitoring System
Roof Mounting
All Interconnections and wiring
All Permits, paperwork (HOA, PUC, Utility)
4.75KW
8433 Kwh
$17,580
$3.70 per watt

Gives me 91% of last years usage but that was before I upgraded the attic to R-50 and radiant barrier. May already showed a drop in usage. Nevada is a Net Metering State so I don't want to go too much over my usage. Estimated break-even is 5 years.

My thought process - I am aware that the Power-One micro-inverters only have a 10 year warranty and accept that. I have a hard time believing that anyone is going to be able to support a 25 year warranty anyway. I rather believe in a bigger company like Power-One now that they are being bought out by ABB will be around in five or ten years. I was also offered the Enphase micro-inverters at the same cost with nearly the same performance. Believe it or not, I liked the monitoring system with the Power-One better than the Enphase Envoy.

So let me know what you think. Give me the bad, the good, the "are you crazy!".

Doesn't sound like too bad a deal. How did you calculate 5 years as break even point? That's nearly $2500/year in savings assuming only incentive is 30% federal tax credit. Also, I'm surprised there isn't a string inverter available that would suit the installation. Of, course, if there is any shading, then micros are probably your best bet. Maybe a slight downsize is in order to use a string inverter because as I understand it, any kWh excess is carried forward indefinitely so it may never be of any value. Plus, you said you have already reduced your energy usage. Remember, the idea is to get the most bang for your buck and excess generation over what you actually use rarely, if ever, meets that test.

[SatManager]

As you noted, from the initial price of $17,580 I would have the federal tax credit of 30%, then the annual utility bill savings of about $1,450, PEC (Production Utility Credits) payments (same as SRECS or RECS in other states) of about $500 a year. Add in inflation factors and it comes out to about the 5 year point.

Another thing that happened here in Nevada is that Nevada Power was approved by the state legislature to shut down all coal power generation plants and replace them with gas and renewable source generation plants. This is going to increase rates to (1) pay to close the coal plants, and (2) pay to build the new plants. And we better hope that natural gas prices don't head back up again as Nevada is now going to have most of its eggs in one basket (gas power generation). And to make it even better - Warren Buffett is buying Nevada Power under his Mid American brand. I think it is a good thing to get as close to 100% away from Nevada Power as I can! Makes those inflation factors above look very favorable.

And we are looking at our first day at 110 degrees. Makes that A/C work even harder.

[Ian S]

As you noted, from the initial price of $17,580 I would have the federal tax credit of 30%, then the annual utility bill savings of about $1,450, PEC (Production Utility Credits) payments (same as SRECS or RECS in other states) of about $500 a year. Add in inflation factors and it comes out to about the 5 year point.

Another thing that happened here in Nevada is that Nevada Power was approved by the state legislature to shut down all coal power generation plants and replace them with gas and renewable source generation plants. This is going to increase rates to (1) pay to close the coal plants, and (2) pay to build the new plants. And we better hope that natural gas prices don't head back up again as Nevada is now going to have most of its eggs in one basket (gas power generation). And to make it even better - Warren Buffett is buying Nevada Power under his Mid American brand. I think it is a good thing to get as close to 100% away from Nevada Power as I can! Makes those inflation factors above look very favorable.

And we are looking at our first day at 110 degrees. Makes that A/C work even harder.

If you are really looking to save money, then, unless you have shading issues, a string inverter would still work. What might look undersized probably isn't and even a 5kW unit would probably not be too oversized. Fronius certainly makes units that would work for your power output. Maybe add another solar panel!

[SatManager]

If you are really looking to save money, then, unless you have shading issues, a string inverter would still work. What might look undersized probably isn't and even a 5kW unit would probably not be too oversized. Fronius certainly makes units that would work for your power output. Maybe add another solar panel!

Problem is getting a company to want to propose doing that. I had 5 companies come in and only 2 companies did string inverters. And the lowest price of those was the sun power vendor. The other came in with a quote of $32,000 for the system. The sun power vendor wanted $26,000. The 3 vendors with micro-inverters ran from the low of $17,580 to $23,000. All of the companies have very good records.

[Ian S]

Problem is getting a company to want to propose doing that. I had 5 companies come in and only 2 companies did string inverters. And the lowest price of those was the sun power vendor. The other came in with a quote of $32,000 for the system. The sun power vendor wanted $26,000. The 3 vendors with micro-inverters ran from the low of $17,580 to $23,000. All of the companies have very good records.

Interesting. Maybe with increased competition among suppliers of micros, the prices are coming way down. What you've described looks like a decent deal so I'd say, go for it!

[SatManager]

Interesting. Maybe with increased competition among suppliers of micros, the prices are coming way down. What you've described looks like a decent deal so I'd say, go for it!

Thanks for the advice. I just sent him an email to schedule an appointment on Monday to sign the contract.

[Naptown]

I can understand the Sunpower being more expensive.
but you could still use the 19 panels with a string inverter and it would be cheaper. It would need to be a power 1 inverter for the two mppt inputs.
that is about a $2000 inverter cost to the contractor.
Wholesale on the enphase for 19 panels would be almost $3000.

[Ian S]

I can understand the Sunpower being more expensive.
but you could still use the 19 panels with a string inverter and it would be cheaper. It would need to be a power 1 inverter for the two mppt inputs.
that is about a $2000 inverter cost to the contractor.
Wholesale on the enphase for 19 panels would be almost $3000.

Actually the quote is for Power one micros. Might they be trying to muscle into the micro market by undercutting enphase?

[SatManager]

I can understand the Sunpower being more expensive.
but you could still use the 19 panels with a string inverter and it would be cheaper. It would need to be a power 1 inverter for the two mppt inputs.
that is about a $2000 inverter cost to the contractor.
Wholesale on the enphase for 19 panels would be almost $3000.

I would still need to find a company that is willing to offer a string inverter system for the same price or less than what the one company is offering the micro-inverter system for. I have two companies that are at $4.00 a watt or less and everyone else is going up from there (all the way to $6.40 a watt). I can't force a company to lower the price. The company that is selling at 3.70 a watt is a very highly rated company, been in business for 15 years and is a large electrical company in the Vegas Valley with many large projects under their belt. They are the only company that has been upfront, not trying the games that some of the companies like to play with pricing, and has discussed options with me for sizing the system. That is why I decided that they would get my business. I was looking for more of everyone's thoughts in regards to the Power-One micro-inverters vs the Enphase micro-inverters.

[Naptown]

I would still need to find a company that is willing to offer a string inverter system for the same price or less than what the one company is offering the micro-inverter system for. I have two companies that are at $4.00 a watt or less and everyone else is going up from there (all the way to $6.40 a watt). I can't force a company to lower the price. The company that is selling at 3.70 a watt is a very highly rated company, been in business for 15 years and is a large electrical company in the Vegas Valley with many large projects under their belt. They are the only company that has been upfront, not trying the games that some of the companies like to play with pricing, and has discussed options with me for sizing the system. That is why I decided that they would get my business. I was looking for more of everyone's thoughts in regards to the Power-One micro-inverters vs the Enphase micro-inverters.

sounds like you found the winner then.
I personally would do the Enphase as they are the oldest and most experienced of the two in this arena.
But that's just me

[jasonsc]

Inverter Decision

I too am having to make a decision on inverters and would like some feedback between enphase and PowerOne. I am going to use LG 285w panels (about 30), live in coastal SoCal. I don't know what the practical clipping would be on the enphase 215 and I have no idea when the 250 is coming out (which would be perfect).

Looking to sign docs next week.

Thanks for the advice for a new guy...

-jason

[russ]

sounds like you found the winner then.
I personally would do the Enphase as they are the oldest and most experienced of the two in this arena.
But that's just me

Naptown is saying "stick with the proven" - that is something we do in industry all the time - proven is far safer.

[SatManager]

I too am having to make a decision on inverters and would like some feedback between enphase and PowerOne. I am going to use LG 285w panels (about 30), live in coastal SoCal. I don't know what the practical clipping would be on the enphase 215 and I have no idea when the 250 is coming out (which would be perfect).

Looking to sign docs next week.

Thanks for the advice for a new guy...

-jason

I have used the Power-One inverters now for the past 30 days and had one inverter fail on the system at the 10 day point but that was with the outside temps at 118 degrees helping keep things really toasty. Troubleshooting was quick and easy and they were able to replace the unit fairly quickly once a new one was received from Power-One. No other problems were seen on the other inverters so I would think that I got one that failed due to heat stress.

I am using Mage 255w panels with the 250w inverter and with perfect weather/sun conditions I have seen the power output to reach 250 - 260 watts for short periods (5 minutes or less). Power-One has the same inverter that is also rated for 300 watts that would be a closer fit for the 285 watt panel.

Amazingly, I am monitoring a 20 panel enphase system (about 4.80kw using 240w panels) and I outproduce him most days. It is here in the Las Vegas valley like I am all panels are facing south. I have a 19 panel system, 17 facing south, 2 facing west. rated at 4.75kw. But most days by the afternoon, I am outproducing his system and total production is more. At least once I got the one inverter back on line. Running on 18 made it an unfair fight. Anyway, I have been really happy with the system. We are in Monsoon season here so the daily weather isn't the continuous sun that you would expect in Las Vegas. You can see my public page: https://easyview.auroravision.net/ea...tityId=1491856

I have spoken to some of the customer service people in Phoenix about some of the monitoring capabilities and found them to be very knowledgeable and helpful. Your installer will have a great support staff available to help him if needed.

[russ]

Amazingly, I am monitoring a 20 panel enphase system (about 4.80kw using 240w panels) and I outproduce him most days. It is here in the Las Vegas valley like I am all panels are facing south. I have a 19 panel system, 17 facing south, 2 facing west. rated at 4.75kw. But most days by the afternoon, I am outproducing his system and total production is more.

That means very little - small differences in orientation, tilt, cleanliness, local morning mist etc can tilt the scales one way or the other.