# Ranger electrically powered?!?

Discussion in 'Electric Propulsion' started by erkki67, Jul 26, 2019.

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1. Aug 23, 2019

### erkki67

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And if a boost by solar panels on the planned wing surface of the Ranger is a way to get close or over the 2h flight time, so why not!

Fritz, what are the actual wing dimensions?

2. Aug 23, 2019

### pictsidhe

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40kWhr of batteries should do it.
You'll struggle to build a battery pack under about 200kg. That will mean a higher gross weight, which will need an even larger battery. Your solar wing would knock 10% off the battery.

It is not currently possible to build a 2hr endurance electric Ranger. This is why people who do the maths drone on about the necessity of efficient airframes... Its nonsense trying to scheme a 2 hour endurance electric ranger. Barn doors make awful electric planes.

If you really want an electric ranger, you will have to change the airframe and target. Stretch the span out and settle for an hour, and you have something feasible.

Last edited: Aug 23, 2019
3. Aug 23, 2019

### litespeed

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It can only happen if you have a hybrid inside doing the charge for the electric systems.

Or make it a slippery motor glider, add solar cells and be very efficient.

Then name it Ranger

4. Aug 23, 2019

### GeneG

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I calculate 307.69 pounds using leaf batteries

Last edited: Aug 23, 2019
5. Aug 23, 2019

### poormansairforce

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You've invented 100% efficient solar cells???

6. Aug 23, 2019

### Speedboat100

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No I just have used the most most suitable planform using 30% efficient cells.

7. Aug 23, 2019

### pictsidhe

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500 square feet of wing area is the wrong ranger.

8. Aug 23, 2019

### pictsidhe

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Really? 24kWh and 648lb

There is more to a battery than bare cells.

9. Aug 23, 2019

### GeneG

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I get 19.6 watts per square foot. Figure 70% of wing area max.

10. Aug 23, 2019

### Speedboat100

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Right..but I claimed a plane with 14 m span.

11. Aug 23, 2019

### poormansairforce

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Here is what a real 14KW system looks like:

Due to an errant golf ball and a sympathetic solar company I know those panels each cost $300. I will let you count the panels. How does that fit into your build budget? And is your hanger big enough? Will you fly on bright, mid summer days around noon time? No? Then subtract substantial amounts of energy production! I know because I watched it like a hawk to make sure my math would add up and it did. A$20,000 system after tax rebate that will never pay off!

BTW: Our landlord put this monstrosity in 4 years ago over my protests to serve the farm of which we are renting the house. He really thought he was helping us out but zero savings since the buyback program knocked us out of the county co-op program. In fact, we just paid the most ever for electric last year in the 10 years we have been here! Its not as easy as you make it sound!

12. Aug 23, 2019

### BJC

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“Alternative energy” is subsidized by all consumers on investor owned utility systems.

BJC

13. Aug 23, 2019

### pictsidhe

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Whereas fossil fuels are subsidised by your taxes.

14. Aug 23, 2019

### Speedboat100

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You are quite right..I asked the company who provided the cells for Solar Impulse a 1 m2 piece...I never even got an answer from them.

NASA and others have access to 30 % efficient film thin panels. Just 3 m2 would provide 1 KW in extra push at optimal conditions.

Last edited: Aug 23, 2019
15. Aug 23, 2019

### erkki67

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So, the battery power has to be multiplied by the factor of 4 before it’s going to be interesting to have a Ranger powered by only electrons!

Remains a GK, Harbour Freight, B/S conversion to stay aloft for at least 2 hours.

16. Aug 23, 2019

### erkki67

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I suppose that the wing area of the Ranger is in the region of 8m2 or 81sqft so there is roughly an max additional 3kw available....

17. Aug 23, 2019

### Speedboat100

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Yes and Lazair would cruise with that power.

18. Aug 23, 2019

### poormansairforce

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FYI, I took that pic at 1:30 this afternoon and in direct sunlight it was producing 7100 watts. When it was new 4 years ago it would have easily produced over 12KW. I saw it with my own eyes. So it shows the degradation of the cells. The cells have a 15 year or so lifespan where they will produce useful energy then are considered defunct. Will you buy new panels every 4 years to keep the energy production where it needs to be?

19. Aug 23, 2019

### 12notes

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You keep repeating this lie, when the designer has stated publicly that it does not.

20. Aug 23, 2019

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