2021 Webinar Series - 25 Thermal Storage

Thermal Storage 

What’s the relationship between peak electric demand, electric storage and thermal storage when considering energy systems? In this program we will hear how a ground loop provides measurable reductions in electrical demand (kW) while it supports the most efficient heating and cooling for buildings. then we’ll learn about a range of existing thermal storage employed in NYS buildings today that might surprise you. Click Here to Register – scroll down and find the date!.


  • Jens Ponikau / Buffalo Geothermal
  • Micah Zender / Melink ZERO
  • Steve Hamstra / GreyEdge Group LLC







            1. Is the freeze cycle a problem in boreholes, a problem when the loop temp drops below 32F?
              1. Usually not. Phase changing from liquid to solid is releasing very much thermal energy, and it simply does take the same amount to thaw again. Our systems are going through that cycle for many years by now, without operational issues.
            2. What does Jens mean when he refers to a six inch footprint? Training needs to leave more time for interaction, to further deployment v. lectures
              1. The single borehole has a 6” footprint.
              2. Not sure what we need training for, we are having 100+ now in operation as the GroundUp group, and use them exclusively on single family homes. They have become the standard for us.
            3. How long will it take to get to what you're talking about?
              1. Steven, not sure if I understand your question. Those systems are operational, we are building them as we speak.
            4. Jens - would you have data to show ground loop temps of GSHP systems over the duration of several years or more -
              1. Certainly. It depends on what the loopfield is designed for, and the layout of the loopfield. In general, you can install larger capacity, and the loopfield is right where it was 1 year ago. Thus no “memory effect”.
            5. Jens - WAs the "Absurd
              1. $$$ 28 million value is kind of an absurd number for a borehole which costs us $15,000- $20,000, but it emphasizes the value of the energy storage the borehole brings to the table.
            6. what depth would you see an average HOME borehole would be? and size?
              1. 400-500ft
              2. We use single boreholes on houses with up to 69,000 BTUs/h heating load. Usually that fits houses up to 4,000 sq ft, depending on the insulation value. We do have 6,000 sqf houses on a single 500 sq ft borehole, if they are new to NYS energy code.
            7. Was the "absurd" $23 million figure based on the life of the loop? If so, how many years? And did it include the corrected number for the avoided energy? - not the typo number
              1. No typo. We are extracting 28,000 KWH of energy. over a 6 month period, at $0.82 per watt, it turns out to be $23 million. The point is that the storage solution has enough capacity for 6 months, which provides resilience. The wind does not have to blow, and the sun does not have to shine…..all winter long.
            8. Hello Steven - the recordings have generally been up on our website within a week after the webinar at the bottom of this page https://ny-geo.org/pages/2021-webinar-series
            9. Melink is Awesome! And Steve Melink is a bonafide “conservation” conservative who reaches across the political divide in advocating that the US lead the “greatest economic opportunity of our lifetime”. Steve H. - thank you!
            10. To achieve replacement of fossil and nuclear energy. Or even a timeline of capacity.
              1. Again, we are putting in those systems daily. The question is how quickly policy makers want us to migrate away from fossil fuels.
              2. But as long as fossil fuels are being paid for by the ratepayers and the costs are socialized, we do not have an even play field. But we can rev up to meet demand. It just has to be the right environment.
            11. Would you think that drilling a 500 sq ft borehole would be more economical than the buried PCM system shown in the presentation.
              1. Yes, less ground restoration, compaction , landscaping.
              2. But also eliminating the need for the header system, and much of the horizontal drilling.
              3. Also much lesser rig mobilization, and only having to steel case 1 borehole
            12. Micah - Is your 73% increase in electricity assuming that building electrification happens with air source systems? Have you calculated how that would be different if heating electrification comes through ground source systems?
            13. Micah - When calculating the increased electricity demand, did you account for the much better efficiency of geo compared to electric and fossil-fuel systems?
            14. Yes Jen, build a better mousetrap and the world will come to your door. Keep it up.
            15. How can you avert rig setup? Thx
              1. Not avert but reduce. Do I set up the rig 5 times for 5 boreholes, or do I set it up 1 time for 1 borehole. Or do I have to case the overburden 5 times or only once? That all does save money!
            16. How deep was the bore hole with 7 tons of connected equipment? I missed that. Thx
              1. 500ft
            17. More of a comment. I think you barely touched on using sensible thermal storage in geological formations. It has much more potential for seasonal storage as is done in Drake Landing that this webinar touches on.
            18. It would be helpful to see how that 73% electricity increase can be avoided by gshp at a COP of ~4
              1. I would argue that it is even more important to avoid the increase in peak electricity demand, which would be 200-400% increase!