Hardware and software improvements may enable geothermal heat pumps to be installed more quickly and less expensively, even in large commercial and industrial buildings in tight urban spaces. I talk it over with Joselyn Lai of Bedrock Energy.
Nice scoop, David. The innovation in drilling using a flexible steel casing sounds good based on my experience with a recent ground loop borehole where the upper loose rock kept collapsing into the hole during drilling.
Joselyn didn't say anything about innovations in the poly pipe or grouting so I assume after drilling, they put in the U-tube and grout same as typical.
One potential misconception was raised, that ground source retrofits of large buildings are usually going to use water to air heat pumps. Quite a few are converting steam or 180F hot water to 140F or 150F HW, and using a large central "water-water" heat pumps to supply that from ground or water or even air or some wild hybrid. Princeton is using 1200 900ish foot deep boreholes and central HPs to supply 145F campus HW to replace their steam heat systems. In the EU there are a number of HPs using lake, harbor or river water as a source with a large HP supplying portions of heat to a district loop. (Their loops are usually at lower temps than 180F, and almost never steam anymore.)
As far as reliability/durability, I couldn't find the twitter thread (Wow, lots of drvolts posts!), but as she said, "failures" in "ground loop" systems these are usually the result of unbalanced loads and undersized loops. (There are consultants and services which specialize in fixing these.) There are also "ground water" heat pumps which pump up groundwater directly and extract its thermal energy and reinject or dump it. This can be efficient in cold climates, but there have been failures due to corrosion, silt, etc. But it's still a thing, it just requires very careful design and maintenance.
As Joselyn noted, indoor heat pumps on water loops are extremely durable compared to almost any HVAC component. They also use less refrigerant than split systems and the circuit is factory-filled and not exposed. Lots to like.
Datacenters don't tend to build their own co-located power, and that'll be due to speed of project approval/completion. There is a lot of interest around building out power quickly (if you are building datacenters at $1b every 2 days everything becomes important), but the fastest path to operations is a grid connection and leaving supply as someone else's problem (e.g. at least a different project manager if not a different company or entity's contractual obligation). Co-location means your data center siting needs to worry about kinds of available power generation prospects, availability of more water, continuity of supply, etc., multipliers to project risk.
Microsoft raised eyebrows when it posted a job description for a nuclear power program manager... because building out the power with the data center is problem that the data center builder doesn't usually tackle. While we all immediately jump to SMRs with that, it is just as likely that they are looking at container sized data center units and a small radioisotope thermoelectric generator for that container - a repeatable unit that you could get some efficiencies in manufacturing(instead of treating every data center as a one-off project with site specific requirements). The primary benefit from container data centers is that they are sealed and humans can't break any of the pieces by doing something stupid in the production environment (we might recall the subsea data center trials meant to improve temperature management - the big finding was reduction in unplanned downtime due to human interactions).
There is always someone tossing around ideas like using the waste heat for power generation or taking the cooling air-throughput for DAC applications, but those are mostly marketing efforts rather than a production playbook.
Having a hard time wrapping my head around these pipes that are used for drilling. They are flexible enough to coil up like a garden hose but yet at these lengths they are talking about (>1000 ft) they have sufficient structural rigidity? As you drill in, um, bedrock there has to be some large axial loads to induce buckling.
Good questions, but that's a specialized and new drilling thing. Apparently it works if they are completing boreholes. And if they reduce some costs eventually, wonderful! I've watched the conventional drilling and grouting, and I know I'm glad I'm not doing it even when it goes smoothly. Maybe Bedrock will eventually have a FAQ but right now the website makes it all sound kinda mysterious.
There is a lot of drilling background info that is taken for granted here. If you are cutting through rock the rock itself does a pretty good job of holding the shape of the well/hole. While you are drilling, traditionally and vertically, you'd have the steel casement (pipes you stack as you go deeper). In operations you withdraw those steel pipes and insert your plastic tubing. The real world usually isn't a solid rock and what you are trying to keep out of the hole is water/water pressure pushing stuff into the way of your drillhead/shaft/drillstring depending on what depth you are going to.
Then you have a decision. Will you ever service the hole or is your servicing plan a return trip to drill a new hole? You might not need to keep the hole open, and your flow pipe will have an internal pressure that keeps it from being crushed (mass*gravity*height applies to everyone - that's pressure). If you want to keep the hole open you'd either leave the sleeve or cast a casement to hold the shape / prevent anything from leaking into the hole and finding its way out at the top. Permanent casements are more of an oil and gas thing where you don't want ground water getting into your fossil fuels. Quaise Energy's whole premise is that the drill itself can fuse the walls of the hole into a casement as the drill advances, dramatically reducing time on site drilling the hole as depths get really deep.
That's probably the last bit. I get a COP of 4.99 on my ground source heat pump at 6' of depth because I had an acre to spread the pipes out into. Drilling to 200 to 2,000' is water well depth. Lots of ways to crack that nut, but the costs are modest so there won't be a lot of margin for innovation. Oil and Gas will go to 10,000' because it is Tuesday. Their depth per hour gets really bad with increasing depth (especially with increasing temperature) which is where Quaise thinks they have a value prop, going to 20km is a big deal because you've got a small town on site doing the drilling at that point.
Predictable costs is where it is at for this use case, spot on from Joselyn. You don't even need the best COP to make it go (aiming at 4.0-4.5 seems like a safe or modest goal to be honest). There seemed to be some talking past each other on space and depth conversations - because this isn't going for primary electricity generation with hot-rock geothermal. You don't want to be too deep and you can't put the bore holes too close together. You are essentially turning the top 1,000' of the earth into this building's thermal battery. In the winter you remove heat, in the summer you pack in the heat. Your spacing becomes the 6-month diffusion length for the heat in the site soils you've drilled into. The depth is the pocket of temperature you can operate in, scaled to the volume of heat you need to move on that 6 month cycle. This built in district approach for commercial buildings is great and I love to see IRA coming into play here. Unlike that previous session on district heat through existing natural gas service lines, this is a clean and plausible pathway.
I have a closed loop ground source (horizontal loop) heat pump at my house.
I have synthesized diamonds in a laboratory and briefly looked into making Carbon-Nitride PDC bits for some of the deep drilling units/challenges that come with directional drilling at great depth/temperature.
Working in IIoT I've interacted with many well and drilling monitoring challenges for a variety of big-name clients.
I appreciate that you covered the geo grid from an earlier episode. Good stuff. There are also grants out in MA to study if gshp will work in additional places. They sometimes get stalled when it’s two different utility doing gas and electricity, can’t imagine why. The northeast is a tough problem to solve for winter heat, but this is great.
I really liked the discussion about value to the grid. Indeed, ground source heat pumps have enormous value to the energy system. 4x efficiency is valuable in itself, but especially valuable is its widespread adoption knocking down the winter and summer peaks from both heating and air conditioning. These are the conditions that cause brownouts and blackouts, the nightmare scenario of utilities. That kind of efficiency is equivalent to the cost of building new power plants, or keeping costly peaker plants on call unnecessarily as the case may be, and that reduced cost is very large.
In a state like Washington, where 50 percent of its electricity is reportedly used for heating and a large share of those heaters are old-fashioned resistance coil type, ground source heat pumps can also knock down that figure significantly, releasing power to be used for other things, like gas heat conversion and the transition to EVs, while reducing electricity bills for residents and businesses.
It seems to me 50 percent is quite a few dams' worth of electricity. How much would about 3/8 of the generators in Washington cost to build now, plus its proportion of new transmission? It's interesting to think of so many retrofits adding up to the value of giant public works projects in aggregate.
Another innovation I'd love to see in this area is the use of heat and cold batteries with heat pumps to store renewable power peaks/cheap power, and more mining of heat from the sewer system in built environments. So many hot showers going down the drain. That's been done for a few buildings in Seattle, but I imagine it could be built at larger scale, with heat plants maybe providing district heating. Of course, someone would have to do that work at large scale to make it work.
Sure you can! Heat pumps move, and amplify, thermal energy. So one unit of electricity to the motor collects 2-3 thermal units outside, and delivers that, plus the motor energy, inside at an "amplified" temp. Everyone has a fridge that's doing this from the cold interior to the warm back of the fridge.
Sounds great. So, gotta ask....when is Bedrock Energy coming to Hawai'i? (Oahu)
PS: Lived in a fully active & passive solar home- in New Hampshire- in the mid-1980s. (Heating bill of $250/year.) Appalled at lack of solar upon arriving in Hawai'i in 2003. 21 years later, Hawai'i has all kinds of resources (sun, wind, geo, waves) yet still imports fossil fuels. Why?
It seems to me that eco-utopians and "Native Hawaiian" activists slowed or stopped deployment of "industrial" solar and wind and geo. Praying that rooftop solar could do it all. And for cheap. Unfortunately, prayers don't generate power.
Nice scoop, David. The innovation in drilling using a flexible steel casing sounds good based on my experience with a recent ground loop borehole where the upper loose rock kept collapsing into the hole during drilling.
Joselyn didn't say anything about innovations in the poly pipe or grouting so I assume after drilling, they put in the U-tube and grout same as typical.
One potential misconception was raised, that ground source retrofits of large buildings are usually going to use water to air heat pumps. Quite a few are converting steam or 180F hot water to 140F or 150F HW, and using a large central "water-water" heat pumps to supply that from ground or water or even air or some wild hybrid. Princeton is using 1200 900ish foot deep boreholes and central HPs to supply 145F campus HW to replace their steam heat systems. In the EU there are a number of HPs using lake, harbor or river water as a source with a large HP supplying portions of heat to a district loop. (Their loops are usually at lower temps than 180F, and almost never steam anymore.)
As far as reliability/durability, I couldn't find the twitter thread (Wow, lots of drvolts posts!), but as she said, "failures" in "ground loop" systems these are usually the result of unbalanced loads and undersized loops. (There are consultants and services which specialize in fixing these.) There are also "ground water" heat pumps which pump up groundwater directly and extract its thermal energy and reinject or dump it. This can be efficient in cold climates, but there have been failures due to corrosion, silt, etc. But it's still a thing, it just requires very careful design and maintenance.
As Joselyn noted, indoor heat pumps on water loops are extremely durable compared to almost any HVAC component. They also use less refrigerant than split systems and the circuit is factory-filled and not exposed. Lots to like.
You seem fairly knowledgeable on this topic. I just posted a question (a bit late to the party). Perhaps you could explain it. Thanks in advance.
Are the typical datacenters using geothermal heat pumps?
Datacenters don't tend to build their own co-located power, and that'll be due to speed of project approval/completion. There is a lot of interest around building out power quickly (if you are building datacenters at $1b every 2 days everything becomes important), but the fastest path to operations is a grid connection and leaving supply as someone else's problem (e.g. at least a different project manager if not a different company or entity's contractual obligation). Co-location means your data center siting needs to worry about kinds of available power generation prospects, availability of more water, continuity of supply, etc., multipliers to project risk.
Microsoft raised eyebrows when it posted a job description for a nuclear power program manager... because building out the power with the data center is problem that the data center builder doesn't usually tackle. While we all immediately jump to SMRs with that, it is just as likely that they are looking at container sized data center units and a small radioisotope thermoelectric generator for that container - a repeatable unit that you could get some efficiencies in manufacturing(instead of treating every data center as a one-off project with site specific requirements). The primary benefit from container data centers is that they are sealed and humans can't break any of the pieces by doing something stupid in the production environment (we might recall the subsea data center trials meant to improve temperature management - the big finding was reduction in unplanned downtime due to human interactions).
There is always someone tossing around ideas like using the waste heat for power generation or taking the cooling air-throughput for DAC applications, but those are mostly marketing efforts rather than a production playbook.
I’m a little late with this buuut…
Having a hard time wrapping my head around these pipes that are used for drilling. They are flexible enough to coil up like a garden hose but yet at these lengths they are talking about (>1000 ft) they have sufficient structural rigidity? As you drill in, um, bedrock there has to be some large axial loads to induce buckling.
Can anyone explain this?
Good questions, but that's a specialized and new drilling thing. Apparently it works if they are completing boreholes. And if they reduce some costs eventually, wonderful! I've watched the conventional drilling and grouting, and I know I'm glad I'm not doing it even when it goes smoothly. Maybe Bedrock will eventually have a FAQ but right now the website makes it all sound kinda mysterious.
There is a lot of drilling background info that is taken for granted here. If you are cutting through rock the rock itself does a pretty good job of holding the shape of the well/hole. While you are drilling, traditionally and vertically, you'd have the steel casement (pipes you stack as you go deeper). In operations you withdraw those steel pipes and insert your plastic tubing. The real world usually isn't a solid rock and what you are trying to keep out of the hole is water/water pressure pushing stuff into the way of your drillhead/shaft/drillstring depending on what depth you are going to.
Then you have a decision. Will you ever service the hole or is your servicing plan a return trip to drill a new hole? You might not need to keep the hole open, and your flow pipe will have an internal pressure that keeps it from being crushed (mass*gravity*height applies to everyone - that's pressure). If you want to keep the hole open you'd either leave the sleeve or cast a casement to hold the shape / prevent anything from leaking into the hole and finding its way out at the top. Permanent casements are more of an oil and gas thing where you don't want ground water getting into your fossil fuels. Quaise Energy's whole premise is that the drill itself can fuse the walls of the hole into a casement as the drill advances, dramatically reducing time on site drilling the hole as depths get really deep.
That's probably the last bit. I get a COP of 4.99 on my ground source heat pump at 6' of depth because I had an acre to spread the pipes out into. Drilling to 200 to 2,000' is water well depth. Lots of ways to crack that nut, but the costs are modest so there won't be a lot of margin for innovation. Oil and Gas will go to 10,000' because it is Tuesday. Their depth per hour gets really bad with increasing depth (especially with increasing temperature) which is where Quaise thinks they have a value prop, going to 20km is a big deal because you've got a small town on site doing the drilling at that point.
Predictable costs is where it is at for this use case, spot on from Joselyn. You don't even need the best COP to make it go (aiming at 4.0-4.5 seems like a safe or modest goal to be honest). There seemed to be some talking past each other on space and depth conversations - because this isn't going for primary electricity generation with hot-rock geothermal. You don't want to be too deep and you can't put the bore holes too close together. You are essentially turning the top 1,000' of the earth into this building's thermal battery. In the winter you remove heat, in the summer you pack in the heat. Your spacing becomes the 6-month diffusion length for the heat in the site soils you've drilled into. The depth is the pocket of temperature you can operate in, scaled to the volume of heat you need to move on that 6 month cycle. This built in district approach for commercial buildings is great and I love to see IRA coming into play here. Unlike that previous session on district heat through existing natural gas service lines, this is a clean and plausible pathway.
Background on Drilling:
https://link.springer.com/article/10.1007/s40948-016-0038-y
https://www.researchgate.net/figure/a-Drilling-assembly-for-directional-drilling-with-an-MWD-unit-consisting-of-FGMs-and_fig3_320511730
Suppliers for deep drilling components (idea what these things look like):
https://www.kennametal.com/us/en/products/carbide-wear-parts/fluid-handling-and-flow-control/threaded-and-standard-nozzles.html
Personal attachments:
I have a closed loop ground source (horizontal loop) heat pump at my house.
I have synthesized diamonds in a laboratory and briefly looked into making Carbon-Nitride PDC bits for some of the deep drilling units/challenges that come with directional drilling at great depth/temperature.
Working in IIoT I've interacted with many well and drilling monitoring challenges for a variety of big-name clients.
https://www.slb.com/products-and-services/innovating-in-oil-and-gas/well-construction
I appreciate that you covered the geo grid from an earlier episode. Good stuff. There are also grants out in MA to study if gshp will work in additional places. They sometimes get stalled when it’s two different utility doing gas and electricity, can’t imagine why. The northeast is a tough problem to solve for winter heat, but this is great.
I really liked the discussion about value to the grid. Indeed, ground source heat pumps have enormous value to the energy system. 4x efficiency is valuable in itself, but especially valuable is its widespread adoption knocking down the winter and summer peaks from both heating and air conditioning. These are the conditions that cause brownouts and blackouts, the nightmare scenario of utilities. That kind of efficiency is equivalent to the cost of building new power plants, or keeping costly peaker plants on call unnecessarily as the case may be, and that reduced cost is very large.
In a state like Washington, where 50 percent of its electricity is reportedly used for heating and a large share of those heaters are old-fashioned resistance coil type, ground source heat pumps can also knock down that figure significantly, releasing power to be used for other things, like gas heat conversion and the transition to EVs, while reducing electricity bills for residents and businesses.
It seems to me 50 percent is quite a few dams' worth of electricity. How much would about 3/8 of the generators in Washington cost to build now, plus its proportion of new transmission? It's interesting to think of so many retrofits adding up to the value of giant public works projects in aggregate.
Another innovation I'd love to see in this area is the use of heat and cold batteries with heat pumps to store renewable power peaks/cheap power, and more mining of heat from the sewer system in built environments. So many hot showers going down the drain. That's been done for a few buildings in Seattle, but I imagine it could be built at larger scale, with heat plants maybe providing district heating. Of course, someone would have to do that work at large scale to make it work.
Wait. You can't have efficiency over 100%!
I'm kidding. But you know that guy.
Who's going to explain it to them? Not me. 😁
Sure you can! Heat pumps move, and amplify, thermal energy. So one unit of electricity to the motor collects 2-3 thermal units outside, and delivers that, plus the motor energy, inside at an "amplified" temp. Everyone has a fridge that's doing this from the cold interior to the warm back of the fridge.
Sounds great. So, gotta ask....when is Bedrock Energy coming to Hawai'i? (Oahu)
PS: Lived in a fully active & passive solar home- in New Hampshire- in the mid-1980s. (Heating bill of $250/year.) Appalled at lack of solar upon arriving in Hawai'i in 2003. 21 years later, Hawai'i has all kinds of resources (sun, wind, geo, waves) yet still imports fossil fuels. Why?
It seems to me that eco-utopians and "Native Hawaiian" activists slowed or stopped deployment of "industrial" solar and wind and geo. Praying that rooftop solar could do it all. And for cheap. Unfortunately, prayers don't generate power.