Originally Posted By: LCranston
I love the concept of Grid- tied systems for saving money every day, but with few exceptions (hybrid systems) they are useless in outages.

I love the IDEA of full off-grid systems, but the batteries are the weakness; they are expensive for what you can store, and do not last. The newer Lithium type-- Tesla, etc., have more cycles and less weight, but 10 times the cost right now. I worked out the math a few years ago, and it was something like 43 cents per KW, about 4 times retail costs in Nebraska after buying the batteries.

I am a fan of small scale solar for emergencies,(small scale meaning 4 or less golf cart batteries) At 85.00 per battery (about 450 watt hours each) I currently have 2, or 900 watt hours stored. It is enough for lights, fans, and Fridge OR freezer (not both). I do not have the panels mounted full time....


Watt hours? Batteries are usually sold with the C20 amp-hour designation (i.e. how many amps of power can be supplied over 20 hours of connectivity). An $85 golf cart battery - I assume you have Trojan T-105s or something similar? Lithium batteries are very low maintenance and have more useful power and considerably more cycles but are crazy expensive. Roughly 4-5x the initial cost of flooded lead acid. The cheapest lithium battery I can get in Canada is $1200 - for just one 12v 100ah battery. (That's just plain NUTS!)

I am presently upgrading the solar on my teardrop trailer. The manufacturer used cheap components and only a single 100w panel which is not enough for off the grid camping. 2 new 200w panels are on the way, I finalized on the batteries I want to get (two 6v 230ah Surrettes), I've got the MPPT controller, temp sensor and remote programmer. Now I just have to confirm if my current cabling will suffice and upgrade the fuse terminal block. Not quite sure what I am going to do with the old stuff yet - the 12v marine batteries will probably go to my brother fishing lodge; the 10amp Chinese PWM controller is a throw away and the 100w panel may or may not be reused.

I am working on a project at work that if approved will have 24k ft2 of solar which is way more than I need for the building but will be sold back into the grid (I work for the power utility!) I am looking forward to proceeding with this project.

You are correct in that the technologies for battery storage and solar panels are definitely improving and getting cheaper. The next few years appear to be promising for solar.

My younger brother is contemplating building a residence at the farm and basically living off the electrical grid. The quote to bring power lines from 2 miles away is at least 2x what it would cost him to build an off-grid solar array. He is a little cash strapped right now and really needs to invest in a storage shed for the farm equipment first. The house trailer was purchased and is ready to go to site this year.