Help powering a skoolie.

[cadillackid]

Originally Posted by HamSkoolie

With such a mission you can probably significantly reduce fuel and electrical infrastructure.
Get a dual fuel (gasoline & propane) generator large enough to run your AC and a little more to charge the batteries. Install a 29 gallon permanent propane tank.
If the solar and batteries aren't sufficient, fire up the propane fueled generator to recharge the batteries and run the AC. You can even get an electric start generator and wire the system to automatically start it when the batteries get to a certain point.
I wouldn't suggest such a system for full time living but for weekends and an annual two week trip it would be just fine. Just know that if you want to stay in parks (which would negate the need for solar so I'm assuming NOT) they may have no generator rules or "quiet hours".

THIS is what I would do.. in actuality if it were *me* I would probably have enough batteries to run at night when sleeping and for light load days.. ie its 72 outside, windows are open you arent doing laundry and the A/C is off but for the hot days and days you wantto do laundry or run lots of loads you fire up a genny and take care of business.. once business is done you shut it down and enjoy the quiet that your solar provides you..



even on hot nights your A/C esp ifits an efficient inverter split will not pull a huge amount of power to keep a bus nice N cool inside. you can have your quiet night by the fire outside before bed and quiet early morning.. if its gonna be a crazxy hot day that day you fire up the genny to run the air-conditioner and let the sun charge the batteries for the following night..



for weekends and even if you factor in only a fuel stop once or twice a week on a long trip you can easily carry enough fuel and water to make Boondocking happen and be enjopyable.. still having the comforts of home.



taking the comforts of home with you is not Taboo nor is it uncommon.. the storage place where i keep my fleet of busses is full of fancy Motorhomes that do just that.. more than one has filled their roof with solar panels so they can run part of each day with the comforts available sans the noise of a generator.

[rossvtaylor]

If you do plan to use a wind turbine, I'd suggest the Air series of turbines...now made by Primus. Keep in mind that a mast mounted on your bus, whether the sidewall or the roof, will transmit vibration and sound into your bus. For some, that might be objectionable.

[HamSkoolie]

If you're talking about my statements on the insurance denying claims due to DIY batteries it's not about the system installation or a pre-owned battery. The problem is when you build your own battery such as our original plan to reconfigure a Nissan Leaf battery as we've seen on the BrocolliBus and Juan's (Beginning from Tomorrow) rigs.
Insurance is always looking for a way to avoid a payout, especially on big ticket items. To avoid that we've chosen to go with commercially built packs that are designed for computer server backup power and fit nicely into server racks.

[DoubleO7]

Originally Posted by HamSkoolie

Insurance is always looking for a way to avoid a payout, especially on big ticket items. To avoid that we've chosen to go with commercially built packs that are designed for computer server backup power and fit nicely into server racks.

You think insurance won't deny a claim when your using batteries in a server rack both designed or meant to be in securely installed in a building?

versus a moving over the road vehicle?

[HamSkoolie]

Originally Posted by DoubleO7

You think insurance won't deny a claim when your using batteries in a server rack both designed or meant to be in securely installed in a building?

versus a moving over the road vehicle?

I don't put anything past an insurance company. If I had my way insurance would be illegal......ALL insurance. Auto, health, life, etc.
Imagine if we didn't have health insurance the health care industry would have to figure out ways to cut costs so that people could afford health care. With a deep pocket third party payer, no one cares about keeping costs down, just about how much they can charge.

[Rucker]

Originally Posted by HamSkoolie

Yes it could have been more clear that you were using a standard 12 volts but I still don't think your math works.
3500 watts of solar, at 12 volts, does indeed come out to almost 300 amps but the but that is theoretical maximum which only exists on paper. It assumes the sun is directly perpendicular to the panel (only happens on the equator or with "tilt a whirls"), the panel is perfectly clean, and there is no obfuscation in the atmosphere. With flat mounted panels there is zero opportunity to meet any of these requirements unless sitting directly on the equator.
While you de-rated the panel output, you didn't de-rate sufficiently to account to all the factors mentioned above. While the period of astronomical noon +/- and hour might need be de-rated only 20 or 30% due to angular inefficiency, dirt, atmospheric conditions, etc. the rest of the light available is going to be converted far at far closer to 40 or 50% efficiency thus requiring a 50 or 60% de-rating.


So, I plugged in Austin Texas to a PV calculator with the following system parameters:
12 VDC panels, 3,500 watt panel output, flat mounted (0 tilt), 14% system losses and 96% inverter efficiency.
The total ANNUAL kWh is only 4,702.
The highest month output is July 533 kWh for the MONTH which is 17.2 kWh per day. In December the output is 7.45kWh per day.


Totally agree. Human nature what it is, very few people with a manual tilt system are going to employ it let alone keep adjusting it to get maximum benefit. In super high latitudes a manual tilt can be quite effective as the sun never gets high. Heck in Alaska the sun never gets high enough to rise for how long each year? Since we're wanting to enjoy Alaska and Canada but I know I'm not going to tilt things, we'll just be buying more generator fuel when our driving doesn't recharge the house batteries (via second dedicated alternator).


I'm not sure I can agree there. While I was initially planning for 1/2 of a Nissan leaf reconfigured and with a BMS installed, INSURANCE is an issue. We met a skoolie couple on the road. After a direct strike by lightening their electrical system fried and the batteries started a fire. This wouldn't be unusual for ANY battery with a lot of juice after a direct strike but because they built up their own battery, the insurance denied their claim.
So if you can't afford to lose everything in your skoolie and take the financial hit, batteries need to be factory items.
I am not going to divulge the source (until we get ours) but there is a current battery on the market with 5.1 kWh of lithium, built in BMS and circuit breaker as well as com provisions for remote monitoring that is just $1500. In a 12 VDC system that's 425ah and $3.53 per amp hour....for a battery with warranty and the all important financial protection over home built.

It's also insanely compact at 100 pounds, and has great reviews. We're going with two.
Four Battleborns @ $800ea (I think they're 900-1000) would bring only 4.8kW at a cost of $3200.
Of course there's shipping unless you can pick them up yourself.



I'm chill, just having some mathematical and engineering type discussion. Nothing personal, just discussing the topic. At least on this end, I think you brought up good points as well.



I think you're right about bias. And that's fine we all have them, the difference is whether we realize it.
Turbines aren't for everyone but here's why we're going to eventually have one or two in our build and so we're planning that from the start so the infrastructure is there. On the coast in Oregon, there is almost always a lot of wind but the sun is an elusive creature, sometimes for weeks upon weeks.

The typical wind speed on the coast where we go is sufficient to drive a 400W turbine to it's 400W production speed. Since the wind blows 24/7 that comes out to 9.6kW, even if it only produces 3kW, that's probably sufficient for our needs on the coast as electrical needs there are minuscule.

As for the 180 mph leaf blower only getting the turbine to produce 8.5W, that 180mph marketing point is at the exit and dissipates rapidly. It's also not going to apply that "wind" to the entire turbine blade surface, and so I wouldn't expect it to produce much of anything other than damage to the turbine. Now a WIND TUNNEL that had a mass of air sufficient to impact the entire blade disk, that would do, so long as it was of sufficient diameter to avoid creating a "shroud" effect.
And OH YES, the folks that think running a turbine, alternator, wheel on the ground, etc. for "free energy"..... I don't think they ever rode a bicycle with a mechanical generator for the lights which flipped over against the tire when needed. Even those little guys you could tell were dragging and making you work harder.


Hope what I've written makes sense, particularly the PV calcs for Texas.

Thanks Hamskoolie! This was an incredibly thoughtful post and I appreciate the careful consideration given to the points I made.

See people! This is how we roll!