Some quotes to compare in Maine

[drburka]

I am building a new house outside of Portland, Me. I have made a decision to move forward with solar panels. I've received a few quotes and narrowed it down to the following. I would appreciate any thoughts/ comments / suggestions. My roof faces 135 degrees there is one tree that has some minor shading but nothing terribly significant. I will have fairly high electrical usage.


1. Panel: (41) 270 Watt all black monosilicon LG solar PV panels
Inverter: (1) SMA Sunny Boy 6000 US Transformer-less grid-tied solar electric inverter
Estimated Production: 13,037 KWH
Cost: $40,479

2. Panel: (44) 275 Watt SolarWorld modules
Inverter: Enphase M-250 or M-215 micro-inverter (doesn't specify which one)
Estimated Production:16,748 KWH
Cost: $38,488


3. Panel: (44) 275 Watt SolarWorld modules
Inverter: ABB (Power One) or Fronius string inverter
Estimated Production:15,778 KWH
Cost: $33,665


Based on my energy usage I'm likely to use all of the energy I produce. Accordingly, I'm leaning towards #2 but I'm interested in everyone's opinion.

In addition to your general thoughts, impressions, suggestions and inclinations, I do have a couple of specific questions.

1. One of the installers recommended I avoid micro-inverter. The house is on the ocean and he said that he sees a lot of problems with micro-inverters and salt water. Any truth to this concern?
2. I know it's been discussed previously but as it relates specifically to this system, any thoughts on M-250 vs M-215?
3. Anything else to consider?

Many thanks!
Doug

[organic farmer]

I have gotten quotes from state-licensed installers in Moosehead, MDI and Searsport. All of them were much higher then your quotes.

I do not see mention of your batteries, are you thinking about net-metering?

Have you read CMP's net-metering contract?

[drburka]

Yes, planning on net-metering.

I have gotten quotes from state-licensed installers in Moosehead, MDI and Searsport. All of them were much higher then your quotes.

I do not see mention of your batteries, are you thinking about net-metering?

Have you read CMP's net-metering contract?

[Rdjntx]

The general consensus here is that unless you have shading issues there is no reason to go with micro-inverters. I would think that would go double when you are on the coast. No reason to add points of failure to your system when you don't need to.

Are those prices before or after tax credits / rebates / or any other incentives? I was looking at a state chart and Maine does not seem to do much for Solar.

Personally I would probably go with #3 and make sure all my appliances were up to date energy saving technology including a properly sized and high effeciency heat pump and then work to save the difference by adjusting my usage.

unless of course the contractor that gave you #2 can so with a single inverter cheaper than what he has currently then it would be a toss up.

there are guys here that will chime in that are much better at this stuff than I am but these are my thoughts.

[organic farmer]

Yes, planning on net-metering.

I live in the Southern half of Maine, about 30 miles North of Bangor. Here we have Bangor-Hydro / Emera as our grid utility company.

To use net-metering;
you first pay the utility company engineer to review your system schematics;
Then you pay an installer who is also an equipment dealer [every installer I spoke with is a dealer and refuses to touch any equipment that he did not sell you];
Then your local city inspections;
and finally the Utility company inspection [which again you pay for].

Then when you are making power and it goes onto the grid. They monitor how much power you put on the grid, the utility company charges you transmission fees, plus taxes on that amount of power.
They will credit you for the power itself though.

If you maintain a surplus of credits, then on days when you need grid power, that amount of power is paid for by the credits you have on-file. But you will still be charged for the transmission fees, plus taxes for that power.

At the end of each month. You will be charged for the transmission fees, plus the taxes on the transmission fees, for any power that you supplied onto the grid.

If you ended the month having produced more power than you used, then you will not be charged for the power, only the transmission fees and taxes.

Your credits are good for 12 months, after which they expire.

There is no context within which you will ever be 'paid' anything.

You will pay for the honor of putting power onto the grid.

Any credits you accumulate will expire after one year.

I have spoken with Utility Company reps. I have a copy of their contract. I have met many times with my neighbors who have chosen to remain off-grid, instead of connecting to the grid.

I only know of one person who net-meters here. He believes that by generating power for the grid he is helping society. So he willingly pays to be allowed to do so.

[russ]

I only know of one person who net-meters here. He believes that by generating power for the grid he is helping society. So he willingly pays to be allowed to do so.

He is the only smart one out of the lot? He has the largest batteries and someone else maintains them.

The conditions you mention seem normal and fair.

[ZoNiE]

He is the only smart one out of the lot? He has the largest batteries and someone else maintains them.

The conditions you mention seem normal and fair.

...But his battery goes off line to him if the grid goes down.

[SunEagle]

...But his battery goes off line to him if the grid goes down.

You can always run a generator when the grid goes down.

If you add up the entire cost of those inspections, transmission fees, taxes and fuel to run a back up generator when the grid goes down, I believe you will find it is still cheaper than running everything from an "off grid" battery system and with a lot less maintenance on your part.

Sure I don't like having to pay people for things that I feel I shouldn't have to but to spend a lot of money for something just to keep some money out of the hands of the Utility is being short sited.

That is like purchasing an EV for $100,000 instead of a fossil fuel burning auto for $25,000. It will take a whole lot of driving on fuel to spend that extra $75,000 you spent on batteries.

Simple math; if gas was $4/gal then the $75k would get you over 18,500 gal. If the auto gets only 25 mpg you would be able to drive over 460,000 miles for that $75k. And your EV batteries will not last anywhere close to that many miles.

But heck with an EV I won't be paying those nasty Oil companies anything.

[russ]

But heck with an EV I won't be paying those nasty Oil companies anything.

1) Just think about how green you would be
2) Just think about all the fun things you could do with the 75,000$

[inetdog]

1) Just think about how green you would be
2) Just think about all the fun things you could do with the 75,000$

Kid to friend: "I sure wish I had enough money to buy an elephant!"
Friend: "What would you do with an elephant?"
Kid: "Oh, I don't really want an elephant. I just want enough money to buy one."

[SunEagle]

Back to the original question put up by the OP.

I think option #3 as a grid tie system (without batteries) is a good one. Even if you end up over generating those additional "transmission costs" will still be less than what you will be saving in the long run. Going with any type of batteries while you have a grid tie is pure waste of money IMO.

[inetdog]

Going with any type of batteries [AS PART OF PV] while you have a grid tie is pure waste of money IMO.

Bold [insertion] is mine.
Batteries may have a place in the overall power picture in the form of a UPS system to tide you over until the generator starts or to carry you through quiet hours of the generator. But there is very little (but not no) point in trying to integrate that into the PV system if your grid is as reliable as typical US.

[SunEagle]

Bold [insertion] is mine.
Batteries may have a place in the overall power picture in the form of a UPS system to tide you over until the generator starts or to carry you through quiet hours of the generator. But there is very little (but not no) point in trying to integrate that into the PV system if your grid is as reliable as typical US.

I agree. Thanks for your clarification. Batteries do have their place if there is a need and justification to prevent a short power loss.