We should see the fourth bid today from a local contractor.

But, we are seeing some standouts in the cost/benefit idea. First, it looks like some Chinese solar panels are probably the best value per dollar. But, we can potentially buy ones made domestically for about $19.00 per panel more. That will probably end up being about $800.00 but we kind of feel it is probably worth it to buy domestic production.

On the inverter side, the Sunny Boy product line seems to be the most cost effective. We have a proposal that squeezes every watt of capability out of the SMA8000 unit. That product in made in Germany. I guess before we pull the trigger I need to review the domestic inverter companies, but I don’t think they will be competitive at this point.

Hopefully this Monday we will be making our decision. I was interested in finding some more data on Schott solar panels and I came across this site: http://www.solardesigntool.com/

I haven’t signed up to use it yet but I was able to do some inverter comparisons that were quite useful. It is better than the Sharp, SMA, and other design sites in that it allows you to compare components from multiple manufactures and it has an ability to sketch the layouts of the panels on the roof.

Very cool!

As I was studying potential compnents for our Ann Arbor residential solar array I ran across a new option.

Solectria inverters may be made in the US so that gives them a couple points in my book.

They seem to have a very wide operating voltage range and a wide MPPT range.

And, they are very cost competitive with the SMA Sunnyboy line.

Finally, they do have a string sizing tool on their website here: http://solren.com/stringSizing.html

So every major installations goes through the decision making process on the solar panels. The crucial things are:

1. Output per dollar

2. Efficiency (If you have limited roof area)

3. How well they match with your inverter or charge controller

4. How well they are warranted

5. The company’s reputation

6. Appearance

7. Company ownership

8. Manufacturing location

9. Company philosophy

I had kind of decided on using Evergreen panels, but then I read that there is a significant concern about the company’s financial stability.

I’ve discovered that two of the major inverter & charge controller manufactures have great tools tools on their websites to help buyers decide what panels to buy and what solar panel configuration to use. Check out Sunnyboy and Xantrex/Schneider.

I spent about four hours looking at solar information again last night. There is a lot to learn.

On the Wind-Sun forum I also read about two scams. One that almost set the house on fire.

I also wanted to collect some links to some of the Solar Design tools I’m working with to get a better understanding for my system in Ann Arbor.

Let’s start:

A solar calculator:

http://www.findsolar.com/index.php?page=rightforme

Sharp’s “Clean Power Estimator:

http://sharpusa.cleanpowerestimator.com/default.aspx

A Good Celcius to Fahrenheit table and calculator:

http://www.teaching-english-in-japan.net/conversion/celsius/

A site for determining your solar panel string size:

http://america.sma.de/newstringsizing.aspx

More to come….

I’ve noticed a lot of PV systems just use conduit to bring the wires off the roof. I want something a little less ugly and I’ve heard good things about the Soladeck product.

I’ve seen them painted to match the shingles and they really blend in well. About $70.00

Here is a roof view:

I thought our plan to put solar panels on our roof was fairly complete. We were going to use
Enphase micro-inverters and just put as many as were practical up there.

But then two new points came up:

1. Electronic reliability is inversely proportional to temperature. And temperature change impacts reliability also. The roof of a house can see -20 degrees on the coldest day of the decade, then go up to 150+ on the warmest day of the decade. An an individual day could swing 60 degrees. That is not the best place to put dozens of inverters.

2. The wife wants some way to generate power with all that hardware up there even if the grid goes down. (There is no effective way to do this with the Enphase product.)

So we are back to a string tie system. Back to the drawing board….