Musings from the Twilight zone

Surfpath · September 2012

"The Twilight Zone" (defn.) An area of ambiguity between two distinct states or conditions

My wife and I have 'moved in' to our 3/4 finished off-grid cabin/house. We are awaiting (island time & budget costraints) the delivery of our main solar/hydro components. We aren't truly settled in, having to periodically journey back to the old house to move the last of our remnants - items that will probably go back in storage for another 15 years. We had to return for 5 days last week before our mosquito screens were installed. It's a little frustrating 'living' in 2 places at the same time: "Where's the WD-40 honey?", "Hey, did you see where I put the keys?" "Those bugs kept me up the whole night."

My wife calls it the "Twilight Zone."

Literally, it's the most important time of the day. After work we rush back to capture the last glimpses of sun, quickly feed the dogs, get dinner on the stove. Then we treat ourselves to an hour and half of generator time. The yamaha starts up and cools the small fridge, powers the washing machine, runs our lights, and a few power tools if need be. The 6kw yammy seems to kick out 2-3 hours of electricity for every gallon of gas (on eco mode). We chose it over a smaller 'briefcase' model in case we needed greater battery charging capacity down the line, but perhaps it'll be overkill looking back on it. After dinner we turn on the tankless gas shower (one of those camping models, the LV100 I believe) which is directly hooked up to the house plumbing. Thankfully, the water is gravity fed.

I'm looking to add a few creature comforts while we await for the PV gear to arrive. A friend says he's got a pretty good 12v 180 amp/hr battery from his boat. I'm thinking about using this to run a few items after we turn off the generator: a 24watt 12v LED ribbon light (1 hour a night?) and, for those very still nights, a 12v 1.5amp 'trucker' fan (2 hours?). I only have a small 0.88 amp battery maintainer, so I think (mainly for the fan) I would need a more powerful charger. There's a 10amp model in the hardware store. Any thoughts on the latter will be appreciated.

The bones of the hydro system are coming together: 500 feet of 2" schedule 40 PVC, the generator, the dumpload controller. I think it'd be wise to get this system in place first to see how much Kwh I can make from it. But there is so much more to do, and I perhaps we have now gotten more used to the generator, the bugs, the dry foods, and yes . . . the twillight zone.

Well, that's the update.
-SP

BB. · September 2012

Re: Musings from the Twilight zone

Sounds like you are one the way to fulfilling your dream (hopefully it is not a nightmare).

Wisconsin or West Indies? "WI"?

If could find Golf Car Batteries (around 220 AH @ 6 volts)--They may last longer (especially if you deep cycle the batteries--Marine batteries are just a trade off between deep cycle and "car type" batteries).

Have a Kill-a-Watt type meter yet? You might find that you can operate with a much smaller genset for most of the time (short of needing to power table saws and large pumps).

If you can get down to the 400 watt average load--A Honda eu2000i (1,600 watt max continuous) will run upwards of 9 hours on a gallon of gasoline (eco mode). Last I checked, they were aroud $1,000 each mail order.

Yamaha also makes some nice inverter/generators too (not sure about their low-end fuel consumption).

I would get an AC charger that will "quickly" recharge your battery bank and put a significant load on your AC genset. For a Honda size 1,600 watt genset, a 40 amp @ 12 volt AC battery charger and 220-440 AH @ 12 volt battery bank would be a nice mix.

If you are going to be running from a small genset for a long time (many months before solar/hydro and/or dark frozen winters), you can read through this thread about why you should find the "optimum" AC battery charger to match your genset:

Question about battery charger selection with EU2000 generator.

-Bill

inetdog · September 2012

Re: Musings from the Twilight zone

Surfpath wrote: »

The bones of the hydro system are coming together: 500 feet of 2" schedule 40 PVC, the generator, the dumpload controller. I think it'd be wise to get this system in place first to see how much Kwh I can make from it. But there is so much more to do, and I perhaps we have now gotten more used to the generator, the bugs, the dry foods, and yes . . . the twillight zone.

Well, that's the update.
-SP

This is nominally a Wind/Sun forum, but all forms of renewable energy interest me, especially micro-hydro. Can you tell us more about your system? (Head, flow, turbine type, etc.)
Without information about that, I cannot be sure, but 500' of pipe, even 2", sounds small unless you have a considerable head pressure and low flow rate.

(I have taken a quick look at the possibilities of micro-hydro for a spring-fed system with a year round minimum (except during drought years) flow of ~200,000 gallons per day, and a max in the neighborhood of 1,000,000 gallons per day, but a drop of only about 50 feet over a 2000 foot distance. It did not look good. Please let me know if I am missing something. It used to drive a 20 foot high overshot water wheel for milling back in the day. With a long open concrete flume. Right now the spring is doing very well as the heat reservoir for a water-source heat pump system. )

Surfpath · September 2012

Re: Musings from the Twilight zone

inetdog wrote: »

Can you tell us more about your system? (Head, flow, turbine type, etc.)
Without information about that, I cannot be sure, but 500' of pipe, even 2", sounds small unless you have a considerable head pressure and low flow rate.

You are correct: Head, friction, (pipe diameter), and flow (GPM) are all key to microhydro. We are looking at 200' head, a 1000' run, and 20-30 GPM flow. With a 2" pipe we are hoping to get 150-200 watt/hr for a good part of the year when water is in abundance. We must also have PV. More will be known with time.

Surfpath · September 2012

Re: Musings from the Twilight zone

Hi Bill,
Yes, we could probably get along fine right now with just a Honda/Yamaha briefcase genny. I sort of went overkill with the Yammy 6kwh.

We have 220v AC here (sorry, my bad, should have explained), so a 10amp charger is equiv to a 20amp 110v stateside (not so?). The big picture is that we have a 48v (8 x 6v Trojan L16's) 435 amp hr battery bank set to come around December - that'll tie in with the rest of our PV system on order.

What I have been offered free now is a 12v 180 amp/hr (probably marine) battery, brand unknown yet. I was hoping to use this till Christmas so that we don't have to run the generator for so long at night. Charging this when the generator (ie fridge, washing machine, lights, etc) run using a 10-20 amp charger is the short term plan. I'll try to post the names/specs of the charger options when I next can. Thanks for your post on pairing chargers with generators. I can see it's not necessarily an automatic thing.

-SP

inetdog · September 2012

Re: Musings from the Twilight zone

Surfpath wrote: »

You are correct: Head, friction, (pipe diameter), and flow (GPM) are all key to microhydro. We are looking at 200' head, a 1000' run, and 20-30 GPM flow. With a 2" pipe we are hoping to get 150-200 watt/hr for a good part of the year when water is in abundance. We must also have PV. More will be known with time.

Hydro in the winter and PV in the summer is probably a better mix than the corresponding combination of wind and solar is touted to be for most people. As long as you have the hydro resource to start with. And 150 x 24 is comparable to 720 watts of PV for five sun hours.

Musings from the Twilight zone

Comments

Categories