Two important factors.The issue with that is "power is power". The ICE is still doing all the work - literally, in the exact meaning of the word - of driving the aircraft. And now it has to produce extra power to overcome the losses in the genset, power transmission system, and electric motor.
Let's say your generator is 90% efficient (pulling these numbers out of thin air), your transmission lines are 95% efficient, your motor controller is 85% efficient, and your electric motor is 90% efficient. And let's say you want 100hp (or Watts) of power at the prop.
Your ICE will need to produce: 100/(0.9*0.95*0.85*0.9) = 153 horsepower into the generator to get 100 hp out at the propshaft. Using a genset and remote electric motor makes the ICE engine have to be bigger to account for the losses in the system. It doesn't allow it to be smaller.
Possible in theory, but today's technology is problematic in achieving that.... short bursts of extra power needed during takeoff and climb.can be supplied by capacitors or a small battery pack...
Claiming Battery Breakthrough, Electric Audi Drives 375 Miles at 55 MPH Without Recharging | PluginCars.comAnd current-day Lithium-based batteries should not be discharged that quickly... you get short battery lifetimes at best, and cell overheating with a nasty fire or explosion at worst...
Ok let get specific, say I want a 5 min aux power launch with one of those 5-10 lb electric engines putting out 16 hp (1 kilowatt =1.34102209 hp) 12KW. How many RC batteries for 75-80% power, and how much will that weigh?The top of the line "Thunderpower" LiPo batteries are rated at 70 C discharge rate, which means that you would empty the cell in under 1 minute. They also have a "burst current" at double this rate. The RC experiences with this technology are all over the map with battery life. However the control line aerobatics guys that fly the exact same pattern (about 5-6 minutes) get hundreds of flight out of a battery pack. They only use 75-80% of it's capacity on each flight. A deeper discharge is what kills LiPo cells.
Thanks much. Would sure be lots easier to start and restart than a Gas Giant Scale model engine. However some development required, control, prop hub, shock mounts, etc. unless there Are Giant scale Electric motors set up for aircraft? Off the shelf, 10-20 KW. with prop hub, shock mounts and controller etc. ????Well the number of batteries depends on the operating voltage of the motor. But I had looked at a 20 hp booster for 3 minutes and came up with a system weight of about 30 lbs. So for 5 minutes (easier on the batteries) I would expect about 20 lbs. of battery.
These numbers improve every year. While storage density changes only 1 or 2% each year, the power density improves 5-10% each year.
=russian inventer works with 2 complets of batterys=1 is discharged,2-nd is loadedTrue.. battery technology gets better continually.. there are LiPo RC batteries now claimed to have 90C discharge ratings.
However, the longevity of these types batteries at high discharge rates is dicey and inconsistent, as any experienced RC pilot will tell you..
Generally speaking, slower discharge rates are safer and have longer battery life, as does preventing the pack from getting too deeply discharged before recharging.
You are right about the first three statements. However, the last one might very soon be challenged.Whether electric propulsion is "worth it" or not really depends on what "it" is.
According to this:
Cost of Power from Batteries and Other Sources - Battery University
..the cost of power to recharge the battery is about 1/5 the cost of current technology Lithium-chemistry battery replacement, on a per hour of use time basis.
This is almost a wash with gasoline-ICE engines on life-cycle cost per flight hour basis today.
So the cost of battery recharging power is very low..
And rapid advancements in battery technology are continually lowering their cost and extending their useful lifetime.
It has already been worth it for RC planes.
It is now worth it for motorgliders and ultralights.
It will soon be worth it for LSAs and other light aircraft.
It may never be worth it for commercial airliners.
The only thing keeping him from mass producing an engine with an efficiency over 100% is the US oil industry. They arrived in their black helicopters in the middle of the night and ...
Ignorance or lack of physics knowledge?