Home solar project

**Walter2** · 09-04-2014, 09:45 PM

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With the help of some friends I installed a 7kw solar system!
I'm averaging about 40 kW a day which is way above expectations.
26 solar world 275 watt panels - SMA sunny boy 6000 inverter (grid tie).
Also installed two Fujitsu heat pumps/mini splits,my goal is to off set heating /cooling/lighting
And hot water. I did a solar hot water system two yrs ago w/electric makeup,and a hot water coil in a wood stove. I think I'm finally getting to a good place! Saved for a long time to do this and it feels good to implement one of my long term plans. The wife and I saved for yrs. and when money got tight we changed our diet to so we could keep putting $$$ away.

**Tokwan** · 09-04-2014, 09:47 PM

How much did it cost ya..all inclusive labor?

**Walter2** · 09-04-2014, 09:57 PM

12k for the solar,mostly my labor and some help from some good friends. Heat pumps vary in price, a standard install for a Fujitsu 1to1 should be about 3k. I buy them wholesale.

**Tokwan** · 09-04-2014, 10:56 PM

$15k....that's about RM45 in Malaysia....my electric bills cost RM200 per month...and that is about $64.00
Make it RM2,400 a year ..almost 19 year...but I guess it would b expensive to install here...it should double that...so its about 28 years...I think there should be some maintenance such as batteries to store the current and the chnaging of batteries...If I live long enough....hehehe...okay, I will stick m=with the current supply, unless they come up with a 100% increase...Thanks Walter.

**crashdive123** · 09-05-2014, 04:57 AM

Awesome project!!!!!

**Rick** · 09-05-2014, 06:20 AM

That's fantastic. I'm curious, did you have to obtain any kind of variance from the city/county to have it installed? How about from the power company? If commercial power is lost how do you prevent feeding power into the grid? That could pose a danger to any linemen working to restore service (gravity switch?). Very cool project. Congrats!!

**Walter2** · 09-05-2014, 08:32 AM

The inverter needs to have AC current to be active,I had to sign a net metering contract with central Maine power co.
They installed two meters. One calculates power in the other power out.
No other special permits where needed.

**Solar Geek** · 09-05-2014, 10:03 AM

Any battery backup for when grid goes down?

**hunter63** · 09-05-2014, 11:41 AM

That is truly awesome.

Would really like to see a step by step thread on the process...including the issues with utilities and other requirements.

Really looked hard into a grid tied system, for 'The Place"....our cabin.......to the point of contacting our local Co-op.

We were first told that they didn't do that.....and the reason was interesting...as they had such a small amount of sales of power...compared to the big utilities....that they were not "required" to.

The back and forth went on informally for about a year...with my point being why wouldn't you or in this case..."WE" (Coop member/owner)....want to do it....all these "seasonal residences" making cheap power for you when people aren't there?

Concerns about back feeding power onto the grid, is handled by a disconnect (required) that trips off the grid if the grid goes down.

Then there was the payback paid at only the rate that they paid for power...varies. Two meters.
So, you would never get a check.....best case is equaling out your purchased power.

We still were talking and I even talked the people at "Home Power Magazine" http://www.homepower.com/ .....in to providing a subscription for the Coop...they did for a couple of years.
Then got a call to tell me that they had reconsidered they idea, and actually had a customer....turned out that it was my up the hill neighbor, a Dr. that built a strawbale alternate house....Very cool. with all the heat, water, wind, composting toilet...everything.

I went to see him...and he has a cool set up, and had been off grid for several years....before connecting up.

From talking to him, and my own research, as well as talking with the Coop....came to the conclusion that a power audit was in order....the price of making a Kw vs conserving that same Kw ....really point to doing the conserve first.

That's where I'm at.....Just did all new windows.

Oh yeah....looked in to the Mini splits heat pump/a/c units as well.....Makes sense in a log cabin....solid exterior walls.

**tjwilhelm** · 09-05-2014, 12:00 PM

ROCK ON, Walter2!

**tjwilhelm** · 09-05-2014, 12:07 PM

hunter63 -- Wisconsin, currently, seems to be discouraging grid-tied solar via legislation and policy. Too, bad. That said, you have a great resource not too far away: the Midwest Renewable Energy Association (MREA). They are located just east of Stevens Point. Hands down, they are one of (if not THE) best training, support, and resource non-profit in the USA for all things related to renewable energy. Their web address is: https://www.midwestrenew.org/ . If you've never attended their annual renewable energy fair, it's a must-do event -- mid-June, every year.

**tjwilhelm** · 09-05-2014, 12:21 PM

In order to add battery-backup to an existing grid-tied (utility-interactive) PV system, you need to consider the following:

- You will not (most likely) be backing up all your electrical loads. You need to select your critical loads that must keep working when the grid goes down. These loads must then be put into a sub-panel, just like when properly setting up a standby engine-generator set to power critical loads.

- You will need to acquire a second inverter/charger and batteries just for your critical loads.

- You will likely be meshing this new system with your existing system using a relatively new technique known as "ac coupling."

Here are a few links to basic info on ac coupling:

http://www.backwoodssolar.com/ac-coupling-explaination

http://www.wholesalesolar.com/AC-coupling.html

http://static.schneider-electric.us/...ion%20Note.pdf

http://www.smainverted.com/2012/10/1...-solar-arrays/

**tjwilhelm** · 09-05-2014, 12:30 PM

Just for fun...

My last batch of PV students installed a 1kW array in only 15 seconds! BUT, we weren't doing a roof install like walter2 did.

Really, just for fun...

**hunter63** · 09-05-2014, 12:37 PM

Originally Posted by tjwilhelm

hunter63 -- Wisconsin, currently, seems to be discouraging grid-tied solar via legislation and policy. Too, bad. That said, you have a great resource not too far away: the Midwest Renewable Energy Association (MREA). They are located just east of Stevens Point. Hands down, they are one of (if not THE) best training, support, and resource non-profit in the USA for all things related to renewable energy. Their web address is: https://www.midwestrenew.org/ . If you've never attended their annual renewable energy fair, it's a must-do event -- mid-June, every year.

Had plans to attend a couple of times, but the time frame is close to the Rendezvous in Prairie du Chein.
Would like to attend at some point.

Thanks for posting this.

**tjwilhelm** · 09-05-2014, 04:15 PM

hunter63 -- here's a current article about the electric utility situation in WI: http://www.midwestenergynews.com/201...-for-business/

walter2 -- I'm so glad you posted your project. Hopefully, others will be inspired to follow suit!

**NightShade** · 09-07-2014, 08:02 PM

Great Job!! Solar is a project I've been saving for as well and want to do after I have completed my aquaponics system 100%

**Rick** · 09-08-2014, 08:21 AM

Obviously they don't work by the hour...er...uh....killowatt-hour.

**roxanwright** · 09-08-2014, 09:48 PM

That's really wonderful. You did great on your solar project. I'm curious, how much do you think will you be able to save now compared to how much you were paying on your energy bills before?