Monday, November 20, 2006

Our home's power station has arrived!

One of our goals in life is to be as self-sufficient as possible. Long before we decided that our house would be a timberframe, we decided that it would be an off-grid home. In other words, we do not intend to connect our house to public utilities. Our house will be powered by solar electricity. I think we can do this, but my wife remains a healthy skeptic. (maybe I shouldn't have spent so much time on the calculator when she asked if solar panels would be able to provide enough energy for air conditioning)

This is a picture of what I call our home's power station. We ordered it from Nathan (he's "good people"!) at Affordable-Solar. This power station takes DC electricity from solar panels (they will sit atop our roof - sorry no pictures of those yet!), charges a 48 volt DC battery bank, and converts that DC power to 120/240 V AC power for use by normal household appliances (I'll let you know if it'll run my MIG welder, because you can bet I"m gonna try it!). From right to left: The two tall rectangles on the right are called Max Power Point Trackers, and they will take power from the solar cells and charge our batteries. The biggest green rectangle houses all of the DC circuit breakers and connections. The two short&wide black rectangles are inverters that convert DC electricity to AC electricty. (there is room for two more inverters above them - I plan to expand soon!) And finally, the green rectangle on the left houses the AC circuit breakers and connections. The output of this panel will feed into a regular "gray" household breaker box. All of the components in this system were manufactured by a company called Outback and then integrated by contract engineers working for Affordable Solar. The Outback manuals are well written and the components seem to be extremely well made. Feels good to buy something made in the USA that creates clean energy.

Here is a picture of the Rolls-Surette battery bank. There are 12 lead acid batteries, each of which produces 4 volts of electricity, giving us a total of 48 volts DC. (and 1000 Amp hours, for 48,000 Watt-Hours of energy storage). Whereas the solar panels are waranteed for 25 years and are expected to last much longer, these batteries (the best you can buy I am told) are warranteed for only 10 years, and aren't expected to last much longer. Batteries are the weakest link in an off grid home power system... or in an electric car, or in a hybrid car, or, well, you name it... battery technology is stuck 100 years in the past! My strategy was to somewhat undersize our battery system (it could provide for 2 or 3 days of bad weather at most), plan on having a backup generator, and hope that battery technology improves by the time these need replaced. BTW, after waving the American flag for Outback, I should admit that these admirable batteries were made in Canada.

6 Comments:

Anonymous Anonymous said...

Oldmilwaukee,
OK, that does it, I can no longer maintain my silence. I have been reading your site for some time and am just so impressed with your work (i.e., my jaw is sore everytime I look at your website from it being in the dropped position). My husband and I drool over your joinery, craftsmanship, creativity...and now I hear you will be off the grid? How cool!

You are one helluva engineer. The stone splitter and cow manure posts makes that aluminum sail you built pale in comparison, if you catch my drift.

Keep up the amazing work. I look forward to your posts all the time. Didn't know that you moved back to Kentucky but it sure looks like you are keeping busy!

Cheers,
Kim

November 21, 2006 at 11:58 AM  
Blogger oldmilwaukee said...

OK, that does it Kim, that's the best compliment I've ever received on my blog. Don't know if the stuff I do these days would pass for engineering, but I do love building. Hoping to do something serious one day... possibly in the alternative energy field. I logged on this evening, secretly hoping for more blog praise, but finding none, decided to do another blog entry about the confounded flashing that I worked on today.

-Oldmilwaukee

PS, You aren't a (quantuum) mechanic by any chance are you? We had two JYW alumni visit here this summer and you would be more than welcome to visit if you are ever in the vicinity.

November 22, 2006 at 9:43 PM  
Anonymous Anonymous said...

Off grid, that's great! We've looked into wind and solar. Mid Tn is not highly rated for wind so we're hoping to go solar. Spent the summer experimenting with our electric usage because like your wife there are just some things I will not do with out- hair dryer! We managed to reduce it by line drying our clothes and changing to those curly light bulbs- "curly light bulb" -latin for "I forgot their real name".

I'm looking forward to reading how this system works for yall.

Adonna

November 27, 2006 at 2:04 PM  
Blogger oldmilwaukee said...

KY stinks for wind too, but there are local variations - our knoll feels pretty windy some days, regardless of the wind maps.

As our incandescents burn out in the double-wide, my wife has been replacing them with those "curly" bulbs. After a year of vigilance, she has replaced nearly every bulb in our trailer! I even replaced one of the incandescent bulbs with an LED light - verdict... LEDs are not ready for mainstream household lighting, but the time for those flourescent bulbs is now! The third time her washer broke down, we decided to buy a super-efficient washer from Staber (since we'll need one when we jump off-grid). This thing is awesome and uses less water, less electricty, and less detergent than a typical washer. I plan to do a blog review of it at some point. I never thought I could get excited abotu a washign machine, but this thing is awesome.

I'll let you all know how the solar turns out for us.

November 27, 2006 at 7:02 PM  
Blogger ww_kayak said...

Ditto, great work. And I have to say, the best part of your blog is that it makes it much easier to explain to workmates and friends what I'm talking about when I say I'm building my own house and cutting my own lumber. As soon as people hear that, they think of Grizzly Adams and log cabins:-) Although, when they see your house, they go the other way... "WOW!, but you can't build something that nice?"
Keep up that good work, and make sure you post the result of trying to run that welder "off grid" :-)

December 11, 2006 at 2:41 PM  
Blogger oldmilwaukee said...

ww_kayak - thanks for the compliment.

I still find it hard to explain to folks what I'm building. After I go through the story of cutting my own logs and milling them, people always say "Oh, I just love log cabins!". Same thing happens when I try to explain my solar-electric panels... "Oh, free heat, that's great."

BTW - nice blog you have there. I especially enjoyed the pictures of your backhoe, and the tales of working on it. I have left that part out of the story out of my blog so far - used equipment woes. The first rule of equipment - it will break. Been lucky with my Backhoe - in over 1,000 hours of service, I've only had to rework 3 cylinders and replace one tire. You were smart to get a backhoe and not a bulldozer. 10 times as reliable and 10 times as versatile. (Don't even ask what I've had to do to my dozer! The short list includes replacing a torque converter, welding together the frame that holds the track on, replacing a charge pump, replacing 5 rollers and a front idler, rebuilding the winch master and slave cylinders, etc.!) Unfortunately, here in hill country, if you want to get logs out and aren't into horses/mules and don't want to ruin your land with a "skidder", you have to have a bulldozer as well. (although a person would do best to "buy" the backhoe and "rent" the dozer.)

Your shed looks awesome!

December 12, 2006 at 9:46 AM  

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