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[John Roberts {JR}]

That site has lots of useful information, but what I am trying to accomplish is not normal for them- any solar wind generator system would normally be used in conjunction with batteries, which for my on grid use are not warranted or desirable.

OK, you have a glorified battery charger. That manages itself when battery voltage gets too high.

You could use several rechargeable D cells to trick that part of it, and then you need to be able to disconnect the load when generation is not able to maintain battery voltage above some minimal voltage level.

Not rocket science but you need a decent current capability switch and ability to compare voltage to an on/off threshold. You might not even need a battery, a large enough capacitor might be enough to smooth out the alternator current pulses. In fact with a large capacitor instead of battery it wouldn't be damaged by low voltage so, no wind, no heat, no problem. 

I would be tempted to also add a temperature sense to disconnect heat when not needed but a simple mechanical switch can do that.

What happens if you just connect the load to the system with no battery?

JR

[Art Welter]

OK, you have a glorified battery charger. That manages itself when battery voltage gets too high.

You could use several rechargeable D cells to trick that part of it, and then you need to be able to disconnect the load when generation is not able to maintain battery voltage above some minimal voltage level.

Not rocket science but you need a decent current capability switch and ability to compare voltage to an on/off threshold. You might not even need a battery, a large enough capacitor might be enough to smooth out the alternator current pulses. In fact with a large capacitor instead of battery it wouldn't be damaged by low voltage so, no wind, no heat, no problem. 

I would be tempted to also add a temperature sense to disconnect heat when not needed but a simple mechanical switch can do that.

What happens if you just connect the load to the system with no battery?

JR

As I explained in the OP, if the load is connected to the system with no battery the generator only works when the solar panels are getting enough sun to hit 10.5 volts while loaded with a 2 ohm resistive heater,  only 8 hours a day or less this time of year, and it stops every time a cloud covers the solar panels.
The  generator requires a minimum of 10.5 volts for it's controller to start working, otherwise the resistive load appears like an "off" switch and  "puts on the brakes", no spin, no juice.

The solution you mention is viable and available commercially for around $150 not including batteries (but the batteries would be shot long before the energy production would pay for the expense, been there, done that)  but require far more design expertise than I have to make myself.

Still looking like a car battery charger with slightly more than 10 amp charge capacity will do what is needed for the cheapest cost, my 10 amp charger came within a volt of the turn on voltage required by the generator, a charger with a "start" feature should handle the resistive load.

[John Roberts {JR}]

Just to be clear, is the 10A battery charger just to start the generator working and wind can hold the load up after started, or must the load be getting 10+ amps continuously for the wind generator to add on top of that?

If the battery charger must put out that much current continuously it may not be designed to do that so could also fail prematurely from over heating.

We come full circle. I would consider working around that regulator that is only happy charging a battery, or connect a battery but that still requires a load disconnect when battery voltage gets low.   

Good luck

JR

[Russ Davis]

Using batteries is not an option, as when the wind dies at night the load would drain the battery...

Maybe I'm missing something, but wouldn't a simple blocking diode solve this?  Even cheap solar kits include them, to prevent current from flowing back from the batteries at night.

[Art Welter]

Just to be clear, is the 10A battery charger just to start the generator working and wind can hold the load up after started, or must the load be getting 10+ amps continuously for the wind generator to add on top of that?

JR

The battery charger (or solar panels) must be capable of providing 10.5 volts in to the 2 ohm load or the wind generator (which is connected to that load) won't start up.
My 10 amp charger was not able to do that, it only could do 9.8 volts, so I'm looking at a more robust charger with motor start capability, which should not mind seeing a very low resistance.

Once the wind generator starts up, it would provides  power to the load, the charger would see around 13 volts and go to trickle charging.

The question is whether a motor start type charger will hold up to providing around 95 watts continuous when the wind stops blowing at night. The 10 amp charger I have seemed to be OK (other than bogging down to 9.8V) so I think a more heavy duty charger should do the trick.

I'm heading off to Harbor Freight now with some resistors and voltmeter to test my theory..

[Art Welter]

Maybe I'm missing something, but wouldn't a simple blocking diode solve this?  Even cheap solar kits include them, to prevent current from flowing back from the batteries at night.

Diodes prevent the solar panels from being a load at night, but I need the load connected to the wind generator, which needs 10.5 volts to turn on.

10.5 volts is what a 12V battery reads when completely dead, which is what it would be after a short period of time connected to the 2 ohm load resistor without power being generated by wind or solar.

[Jonathan Johnson]

I'm imagining a separate anemometer that connects the battery to the system when the wind speed exceeds a certain threshold, thereby activating the turbine. When wind speed drops below the threshold, the battery is disconnected.

[Mike Christy]

Seems like what you need Art s a relay to open the load ( the heater ) from the battery when the turbine isnt turning (no wind).

Attach a cheap deep cycle battery as normal, attach the heater across it as normal, then gin up some way to sense when the gen is charging - those status LEDs and a photo sensor possibly, or just a comparator circuit to sense higher than dead battery voltage, open the load relay when the turbine isnt turning.

So in essence the heater only works when the turbine is turning.

Maybe?

[Art Welter]

Seems like what you need Art s a relay to open the load ( the heater ) from the battery when the turbine isnt turning (no wind).

Attach a cheap deep cycle battery as normal, attach the heater across it as normal, then gin up some way to sense when the gen is charging - those status LEDs and a photo sensor possibly, or just a comparator circuit to sense higher than dead battery voltage, open the load relay when the turbine isnt turning.

So in essence the heater only works when the turbine is turning.

Maybe?

Again, the solution you mention is viable and available commercially for around $150 not including batteries (but the batteries would be shot long before the energy production would pay for the expense, been there, done that)  and requires more design expertise than I have to "gin up" myself.

[John Roberts {JR}]

I'll try not to repeat myself but lets look at the power math.  125watts from solar, and 250watts from wind "day round" (peak, ave, other?). You suggest a load of 1-2 ohms. A voltage range of  10.5V min for regulator operation, max V of 18V(?).

FWIW 18V is only 325W into 1 ohm load so if power output is capable of 18V that sounds ballpark.

If an external (hard) 10.5V power supply has a steering diode in series with it's (11+v) output, it can supply current only when the solar and wind is not. Once the solar and wind is putting out more than 10.5 amps at 10.5 volts, the power supply diode will stop conducting and the load is completely driven by green energy. 

The way (cheap) battery chargers are designed is to provide a "soft" voltage supply higher than 12V. For example a 13.5V hard voltage source with say 0.2 ohm in series. At 10.5V that is 15A draw, at 12.5V 5A, at 13.5 0A. As the battery charges up the current draw naturally drops off, so connected as you suggest, at 10.5V the battery charger is putting the full 105W into the load. As the solar/wind output rises, the contribution from the charger drops off as the power into the load increases, but for a typical battery charger it will still be supplying some power all the way up to 13-14V

So this will work, IF you can find a charger that is happy to put out over 10 amps, perhaps for some significant time duration if left on when green energy is not producing at least 100W. If you can't find a battery charger that works, I would look for a dedicated say 11V (12V may be more common) 10+ amp power supply then add an output steering diode. You will lose at least a 1/2 V more like 3/4 from the steering diode, so  12V nominal is not crazy. (note: this is not a small diode and it will need a heatsink to dissipate a few watts itself.)

A simple(?) thermostat could turn this power supply on/off when inside temp is above target, while it might make sense to heat up a hot water tank or find some way to hold excess energy captured. 

Have fun...

JR