[IWarm]

AC, etc.
I have read most and skimmed all of this thread and several others related and linked. I have followed many tangents. Whew!
Thank you AC for starting and attempting to maintain focus. Thanks also to all others that have contributed their knowledge and also those searching for answers.
While I have benefitted greatly, no one has attempted to do exactly what I plan to try.
Before I describe my project, allow me to offer what I think may be helpful, especially to you AC.
The label 'Ground source heat pumps' may be leading us astray. AC, you have repeatedly discussed the differing heat exchange rates of air and water when focusing on the HX. Yet, you haven't fully applied this knowledge to what happens under ground.
When you refer to rain as a 'heat event' I suspect you're simply too close to see that the heat carried by the rain is only part of the improved result. Perhaps the smaller part. Rain is also improving heat transfer from your normally dry ground.
I suspect that many of the GSHP systems that fail to deliver satisfactory results are similarly located in dry ground.
For those of us blessed with a high water table, when it comes to the storage of heat, it is important to know what type of water source we have, ponded or flowing. We have a glacial esker in the center of our property. When the truly artesian well was drilled, they logged 35' of gravel. To the east we have 100'+ of brook joining 800'+ of river. These above ground sources drop a combined 30' from north to south and are indicative of what is happening under ground. Our ground water flows from north to south. Any heat or coolth I take from the ground is quickly replaced from the north. Only those with a dry ground or a ponded water table can reasonably expect ground storage to hang around long enough to be useful.
I do hope this is useful. It is all I currently have to offer.
Thanks again,
IWarm