Diversion Loads/Dump Loads

i have no a-z instructions for you, but

photovoltaic charge controllers do not require dump loads.

wind controllers usually come with the turbine, but if you have a home-made or other smaller unit, you will need a diversion load controller (morningstar tristar, xantrex c-series) and a diversion load.  the diversion load must be able to handle the power from the source and are often required in duplicate (both controller and dump load) by code in case of failure of one.

hydro is much the same as above with the exception that no hydro comes with controller provieded by manufacturer to my knowledge.  all will require dump load controller and dump load usually in duplicate for safety.  these can be resistive loads to air, or to water for heating.

batteries and (off grid) inverters dont care where energy comes from as long as it is regulated and in the paramaters for its proper operation.

james Alt-E staff

Wait a minute.  Did you say that you think diversion loads are optional?  Diversion loads are not optional with hydro or wind.  These devices create electricity from spinning a driver which spins a generator.  Once you have something spinning, its not easy to stop.  If you immediately remove or reduce the braking action (in this case that's the electrical load that they have been ramped up against), they can sometimes take off.... sometimes all the way off.  The diversion load is needed to hold them in place and in one piece, and cool, until they can be ramped back to the new power level output required for the new load.  That's if you have control over the new rpm needed.  Changing the flowrate to a hydro, for example (but you can't change the windspeed so easily).  Until then you have acceleration and a possibility for very high voltages, if the load is ramping down, or brownouts from equipment coming on line, but trying to operate on too low power levels as the load is building, but supply remains relatively low.

I had a look at the AirX cut sheets and they have a speed cotrol that they say kicks in when the batteries have charged and stops the turbine.  When the batteries are charged, apparently the turbine will not start.  That means that, while the batteries are receiving all current, a load "diversion" is not needed as the battery takes 100% of load, and when they are reaching charge, speed control begins and current is limited to less than what can be produced without a diversion load, when charged, breaking kicks in and the stopped turbine (of course) produces nothing and needs no load diversion.  Therefore the AirX turbine does need to accept full load and needs load diversion capability, OR needs speed control while actively spinning.  My previous post above wasn't clear as I did not mention that I was assuming that the case being discussed was limited to fully spinning-free conditions, under which all turbo-machines need load diversion, of which the AirX is no exception.

For efficient use, yes.  A charge controller charges the batteries in a controlled manner, permitting greater current to be sent to the batteries when they are low and reducing the current to the batteries when the charge level comes up.  It isn't a necessity to have charge control, but if not, high currents would be sent to the battery even though they lack only 1 mA from being full.  The idea is that a good portion of those high currents could be used elsewhere whenever the batteries do not need to be charged at full rate.

The Xantrex C Series for example can be used as solar charge controllers or load controllers or load diversion controllers. I haven't been looking closely, so if these aren't, I believe there are multiple input models out there.

I'm not much of an electrical engineer, but as I like to think of it, there are basically two types of generators  used in renewable energy, PV and batteries are one and then the induction type Wind/Hydro generators, which are really just induction motors spinning in reverse.  That's leaving synchronus generators aside.  PVs and Batteries do not derive their voltage from the circuit they are supplying (within limits), whereas induction generators do.  Induction generators need an electric field in which to spin in order to generate their voltage.  The strength of the field is determined by the circuit they are supplying.  Therefore changes in the circuit load, change the field of the generator and consequently change its output.