Ultimate designs - open discussion

[rvmaker]

There are generally two ways to make it: Fixed panels on the roof, the more, the better, or active sun-tracking device. Latter sounds more suitable for a vehicle because less weight combined with limited size makes a better compromise. It gives more output power with less weight to carry around. It also works better in the high north.



One panel weighs around 25 pounds (11.5kg) and gives out max 150W. My test set is drawn on short Ford Transit high roof. Size of the flat area on the roof is 56.7” width 96.06” length (144cm x 244cm). After some study, it seems like flex panels should not be used. They have all sorts of problems - cracking, going milky and losing power to mention a few. Some just quit early, after two years. History draws a picture of not too many happy owners. With common sense, it seems quite apparent plastic will not survive in direct sunlight, and those things are almost all plastic.




Vehicle support is bolted inside the van, utilizing existing ribs. Only holes in chassis are for bolts and wires.


In the given area, I can almost fit four panels, so I compromised to install four. Nominal output is max. 600W.

If cells can be pointed directly at the sun (90°), it increases output around 30-35%, meaning more power with less surface, in comparison to fixed cells. Directing is mechanically complex and creates multiple potential points of failure.




The rotator is Lazy Suzan aluminum bearing, size 20” (50 cm) model ht1582. It should be able to take more than 220 pounds (100kg). The whole set with panels weighs around 123 pounds (56kg). Gears are laser cut from 2mm and 4mm aluminum. Square tube structure is 20x40x1.5mm aluminum, that should be riveted together with supports. Welding is an option, but rivets are sturdier but also making possible fixing easier.



The linear actuator is cheap Chinese 29.5” (75cm) 12V from eBay. It should be able to lift 600 pounds.



Rotator motor is TsinyMotor worm gear 12V.


I used in the design only components available on eBay, but I have no info on how they fit the purpose. I ordered samples and make a test rig when they arrive. Possible problems rise with time and weather.

Price for the whole set should be below $1000.

[rvmaker]

Started to wonder what happens when the airflow gets under the panels and made scetch for a windshield.







This image shows benefits for 3D designing software. 100mm actuator will be on the way when panel rotates. This part needs to be redesigned or adjusted. It is good to notice at this point before any parts have been made.



For a similar reason, I had to flip long panel actuator 180° vertically – the rotator motor collided with actuator motor.

[rvmaker]

Like this.

[rvmaker]

This is the latest image.

Now the car is modeled.






The bearing. The ring is wide enough to drill holes. I put plate on in and rotated myself on it. I guess this can take a lot more than 200 lbs (90Kg).





The actuator has some power (according to this plate, no clue what the actual values are):

[bushpilot]

I would expect you'd want the tilt from SIDE (of van) to side...not front to rear.

[rvmaker]

Good point, if I get you right.
I did spend some time with this.

Design guidelines:

1.) The panel must be easily and rapidly deployable = Press-button-No-human-intervention-fully-autonomous. Relative position towards The Sun must be free, so no need to move the vehicle for the panel. There are situations where the car position cannot be chosen.
2.) It should be deployable in an urban environment without the hassle or without it taking too much space around the vehicle – meaning not to draw too much attention.
3.) It must be light enough to be operated by parts readily available.
4.) it must be light to carry around. Every pound counts.


The panel works even when not deployed; it just gives less power.



The "standard" solution is just to put 3-5 panels on shelves and pull them out to each free side with rails. This has drawbacks on high latitudes. Other side panels are easily partially shaded by panel structure itself. Such panels need more control electronics that add more weigh or are just simply useless. The weight itself is in many cases restrictive.

The other way is to fold them to open doubling the area.

Ecos Power Cube
https://www.ecospheretech.com/enviro...gies/powercube
is an excellent fixed base solution to Afganistan where U.S. military gallon cost over $400: https://www.cbsnews.com/news/real-co...bases-400-gal/

https://www.youtube.com/watch?v=1wT15-4UAvI

The best way would, of course, to use panels as shade to cover the vehicle, but that might exceed weight limits. I have not gone to this yet.

On high latitudes, you gain around 30% less than at the equator due to declination. It can be compensated by pointing the panel at the sun. This thing is not designed to equator +-23.5°


BTW: I wonder why people are adding generators when this is available:
http://www.militarysystems-tech.com/...6-Brochure.pdf
You can find it on eBay as surplus for $400-900. The free market price is around $12000. 570A 28V equals something like 11KW usable energy. Max take from the truck engine is about 20kW. The best thing there is no extra motor to carry around.

[bushpilot]

Originally Posted by rvmaker

BTW: I wonder why people are adding generators when this is available:
http://www.militarysystems-tech.com/...6-Brochure.pdf
You can find it on eBay as surplus for $400-900. The free market price is around $12000. 570A 28V equals something like 11KW usable energy. Max take from the truck engine is about 20kW. The best thing there is no extra motor to carry around.

do I understand that to be a generator that is chassis/engine powered?
are those USD $ (if so thats quite expensive).

The challenge I see is it (may?) require the engine running to operate/generate - my chassis engine alternator already charges my house batteries when im running down the road (or idling)...but running a 13L engine to charge batteries is excessive and unnecessary (its a benefit while driving, but I wouldn't want to do it at camp).

our 10kw generator (Onan quiet diesel - 3cyl Isuzu) burns no more than 1/2 a gallon of diesel fuel at FULL load....more likely I rarely consume 1/4 - 1/3 a gallon of diesel fuel per hour....diesel is cheap (in the states @ $2.60 (USD) per gallon....

https://www.gasbuddy.com/GasPriceMap?z=4

[rvmaker]

Originally Posted by bushpilot

do I understand that to be a generator that is chassis/engine powered?
are those USD $ (if so thats quite expensive).

Yes, belt driven from main motor, price is USD.
https://www.ebay.com/itm/CATERPILLAR...kAAOSwCHZaqRVS


In Germany or Austria, there is plenty of 7-12 ton EURO2, 3 and 4 trucks available with extremely low mileage (< 30000) price ranging from USD5000 - 8000. The price is low because of the tight emission regulation in German cities. The truck must be EURO5 or 6 to enter most major cities.

Such trucks have 4-5 Litre engine; power curve parallels with CEN alternator. I plan to acquire Nissan Leaf battery 30/40Kw and charge it with CEN.
This CEN alternator has a pretty impressive power curve, and it even gives out 14V 50A at the same time. If you have Leaf 30Kw battery, it takes less than 3 hours to charge it fully from empty while driving.


30Kw should last at least a few days in regular RV use with modern appliances. With such a small truck 3 hours per week commuting should be doable if an EV charging station is not available.


This is the smooth side of starting from zero - I can choose the best options from what is available. I plan to solve first energy issues, then water and let them set the frame how the rest of the vehicle is made. Who knows, maybe I find something new? Two weeks back I met a Finn guy making electric buses in China. He had an idea to make a fully electric luxury RV.

In Europe Diesel has price around double what You have.

Nice service that GasBuddy. First time I see it.

[Proteus]

Originally Posted by bushpilot

(in the states @ $2.60 (USD) per gallon....

Almost twice this price here in Europe, 4,80 € for a gallon of Diesel.

[bushpilot]

Originally Posted by Proteus

Almost twice this price here in Europe, 4,80 € for a gallon of Diesel.

4,80 € OUCH...really OUCH ($5.40 USD)

Kalifornia isn't even that bad....they're $3.75 - $4.25 a gallon

[bushpilot]

[QUOTE=rvmaker;48511

Nice service that GasBuddy. First time I see it.[/QUOTE]

GasBuddy is another one of those crowd sourced apps like Waze.

crowd sourced.... only as good as the people reporting / confirming the pump prices.

It's available as a smart phone app - the application use your GPS location to present the lowest price w/in proximity of where you are / need it.