Off Grid.

[junkhound]

Anyone done an off grid system? Lessons learned?

Have a grand-daughter and fiancé looking at building where bringing in grid power will run $20K.

Helping them look at alternatives, possibility of a wintertime creek flow of 1.4 GPS at 25 ft head, but just a trickle in late summer. Western WA so limited solar potential even in summer.

They think they can live with a 5-10 kW-hr per day summertime base (no AC needed).
I built a concentrating tracking solar array on Mt Haleakala 20 years ago that produced 15 kW-hrs per day that I could reproduce, but that was mountaintop HI vs. cloudy western WA.
My shop can build a 5 kW-hr Li-ion storage unit if I need to help them out, but probably need to replace every 4 or 5 years.

 

[hillbilly1]

I have a customer wanting to put in one of these low head systems, he has plenty of flow, just not a lot of head, as he is in a valley. https://www.powerspout.com/
Would a wind turbine be feasible at the site?

 

[electrofelon]

I lived off grid for 10 years and did a few other off grid systems. I don't recommend living off grid nor doing any such work for pay. Most of the time people don't understand the limitations and how much work and maintenance it is. 20k is not bad at all for grid power. You will spend that on high priced equipment, ultra efficient off grid appliances, a generator, gas, batteries, replacement batteries......then there is the constant worry in the winter time about having enough juice. If I was independently wealthy and didn't have a zillion other things to worry about, I could probably get into it.

 

[junkhound]

If I was independently wealthy and didn't have a zillion other things to worry about, I could probably get into it.

Great reply. I'd be excited about helping them set up a system if I were not working 60 hr weeks for aerospace company designing HV dc power supplies, would be just like aerospace work without the pay....

No realistic potential for wind power as the property is covered with 100+ ft tall D Fir. Reason for living there is the trees.

 

[GoldDigger]

Ditto to electrofelon. Once you have amortized the initial cost of either the utility power or the off grid power, the cost per kWh from there onward will be far less for grid power.
If the customer is committed to off grid the combination of solar PV supplemented in winter by low head hydro sounds attractive.

 

[winnie]

Solar panels have gotten cheap, so it doesn't pay to use tracking or concentration to improve panel efficiency, and the do produce on cloudy days...but I son't think they've gotten cheap enough for this project.

According to https://www.turbinegenerator.org/solar/washington/ in Washington in the winter you are looking an an effective 1.6 peak sun hours per day. To get 10kWh per day (small user) you would need a 6kW panel array. Then energy storage and all that such entails.

Would micro-chp work in this situation?

-Jon

 

[drcampbell]

Concentrating collectors are effective only under clear skies.
Direct sunlight passes through (or reflects off of) the concentrating optics and lands on the collector, but diffuse sunlight passes through the optics and lands on some random place other than the collector.

Likewise tracking -- pointing the collector directly at indirect light isn't very effective.

It might be possible to increase output maybe 50-75% with reflective surfaces above & below the collector. (triple the effective collection area)

 

[ron]

Are there some jurisdictions that would prohibit having an occupied dwelling without a minimum sized energized utility service? For example, if my potable water or sewage were to stop, the dept of buildings would likely make me exit my home as dangerous. BTW, I live in a nanny state.