DIY multi stage Heat Pump from multiple compressors

[gadget]

Originally Posted by NiHaoMike

It would be simpler to use a VFD, possibly in combination with a switchable displacement compressor for more dynamic range.

I'm actually looking at something like that for a thermal storage system, using a 2-4 ton switchable displacement compressor in combination with a VFD to try to match compressor power draw to surplus PV power available. That's pretty far out, however, as I will work on other parts of the solar power setup first.

VFDs are getting cheaper. Still out of my price range though. What type of thermal storage are you working on?

I was working on a setup where a solar load diverter would power a compressor with off the shelf parts. There are some DC compressors that could work. I was thinking one of the 3 phase brushless units and a load diverter solar charge controller. I know of one charge controller thats PWM output. Not sure how that would work with a brushless motor controller.

I have a load diversion solar controller but I think I'm going too try diverting power to some LED modules for adding extra grow light in my greenhouse for now.