What really grinds my gears is that we pay good money for an engine in a car but we don't seem to get vehicle to home power solutions. Also it doesn't seem that wind turbines are that effective for the average home owner. Has anyone thought of sticking a wind generator on a car's wheel hub and plugging it into an inverter?

On 2022/12/22 at 4:13 PM, frivan said:

Has anyone thought of sticking a wind generator on a car's wheel hub and plugging it into an inverter?

Internal Combustion Engines have terrible efficiency, of the order of 25%. Then the hassle of coupling to a generator. You may as well use a generator designed for the purpose. The problem is that generators' output isn't all that steady, so many inverters don't like to take their power via the AC-in port. A generator powering a battery charger usually works, but that's a lot of conversion steps, so efficiency isn't great.

After the X-mas eatery perhaps a battery mounted on a bicycle carrier. Attach a genny to a wheel to charge. Only use level roads as it would feel like uphill all the time. 

Should work for the figure

9 hours ago, Coulomb said:

Internal Combustion Engines have terrible efficiency, of the order of 25%. Then the hassle of coupling to a generator. You may as well use a generator designed for the purpose. The problem is that generators' output isn't all that steady, so many inverters don't like to take their power via the AC-in port. A generator powering a battery charger usually works, but that's a lot of conversion steps, so efficiency isn't great.

Thanks for the input. I also think a small gas generator may be a good backup for a rainy week. However, the noise and variable power quality worries me. Once you start talking about quiet Diesel generators, you start running in to tens of thousands of Rands. I suppose my question is if there is a cheap backup solution utilizing my car and Sunsynk inverter? What about a 12V to 48V boost charger?

6 minutes ago, frivan said:

Thanks for the input. I also think a small gas generator may be a good backup for a rainy week. However, the noise and variable power quality worries me. Once you start talking about quiet Diesel generators, you start running in to tens of thousands of Rands. I suppose my question is if there is a cheap backup solution utilizing my car and Sunsynk inverter? What about a 12V to 48V boost charger?

Check the 12V output. It is normally limited to a small % of the 220V. The 220V to 48V is a much better option. 

5 minutes ago, Scorp007 said:

Check the 12V output. It is normally limited to a small % of the 220V. The 220V to 48V is a much better option. 

I think most 12V sockets in your car would be rated for 100W. But if you connect to the battery you could probably draw 100A. I think I would let my car idle for 1kW of backup power.

57 minutes ago, frivan said:

I think most 12V sockets in your car would be rated for 100W. But if you connect to the battery you could probably draw 100A. I think I would let my car idle for 1kW of backup power.

Sorry I missed the car portion. Answer applied to the 12V circuit on a generator. 

At idling the car alternator could perhaps provide 30A but could overheat due to slow speed and reduced cooling. Depending on the vehicle a burnt out alternator could be a costly experiment. This nett discharge of 70A will get you a close to flat battery after say 2 hours. 

Then you need a very costly DC-DC converter 12V to about 52ish volts. 150W boost chargers are very cheap. The higher output curve is steep. 

Then there's the fuel cost, the average 1.6l engine idling away around a litre of petrol per hour at R23.92 for one kWh of energy... ten times the price of Eskom.

Better to get a 1kW generator, else much much better to use a solar inverter and battery.

Edited December 26, 20222 yr by GreenFields

3 hours ago, GreenFields said:

Then there's the fuel cost, the average 1.6l engine idling away around a litre of petrol per hour at R23.92 for one kWh of energy... ten times the price of Eskom.

Better to get a 1kW generator, else much much better to use a solar inverter and battery.

Some 13years ago I found my Jazz used 0.5l/h while charging a 24V battery via DC-DC converter at idle . My 600W genny used just below 1l/h.

When you get only 10% of normal PV yield the cost of fuel becomes of lesser importance I guess.