Geothermal and Geothermal Battery (Changed Title 12/21/23)

kbd512 · 2023-02-03 07:55:15

Terraformer,

Those heat pumps look great on paper, but like so many other paper concepts they don't quite pan out in the real world. Unfortunately, it assumes a level of building insulation and sealing not present in most as-built structures in Western Europe, unless you're talking about the homes and buildings in Nordic countries. If the home was much better insulated, then a heat pump makes a lot more sense. Tens of thousands of dollars or pounds would have to be spent insulating and sealing homes before spending a dime on heat pumps. At that point, your spend on heating and cooling has already dramatically reduced. We bought truly sealed windows for our last home and our air conditioning / electric bill was reduced by a third- 750kWh/month to 500kWh/month.

Terraformer · 2023-02-03 08:37:09

Oh for sure, the terraced house I'm in is probably losing several kilowatts of heat on cold days (which for Britain, means just above freezing). I figure with proper insulation (and window coverings) we could get it down far closer to a kilowatt, though it's hard to tell how much insulation we'd need because of too many sites giving R values 6x higher than they actually are because of some "imperial measurement" thing they have going.

British houses are woefully under insulated. Comes from not having winters cold enough to kill people in uninsulated homes j guess.

As for heat pumps, a 20c source would improve performance a lot. New refrigerators can be bought for less than $1000, so that's an upper limit on how much a (very small) heat pump would cost to manufacture. I don't think the cost will scale linearly with power though, wouldn't you just be scaling up everything? No complexity increase...

EDIT: oh dear. The misleading American figures for R values have maybe made me miscalculate how much heat is lost. With a 10 degree difference, assuming the stone walls have R values of 0.2, it could be losing 6kW through roof and walls; on the coldest days, 10kW. Even bringing that up to an R value (proper, metric) of 1 could bring the energy use down by 80%. That's ignoring the holes in the roof (you can see patches of daylight in the loft) which my parents still haven't had fixed despite them letting in water and wasps and letting out heat for two decades since they bought the place.

I think, if we can get it sealed, install heat recovery ventilation (if you're going for airtightness you need it), and insulate the walls and roof up to an R value of say 2 (more in the roof, less in the walls) we could get to the point of needing 100W per degree of temperature difference. That would give about three degrees just from body heat (counting the dogs as 50W each), so maybe 1.5kW to keep it at a comfortable temperature on cold winter days.

Last edited by Terraformer (2023-02-03 09:26:05)

SpaceNut · 2023-02-03 19:14:03

Is there an equation link Terraformer, for the heat lose if you know the r value? That would aid in the thermal amount to save daily knowing that you are banking this during the summer.

One issue for deep heat well drilling is that there is not any reliable data to base just how far you will need to drill for a given level of heat. That makes each wells price go up and will be not less that the high that kbd512 gave earlier.

That means for my purpose I need thermal tank volume and as high of a temperature to be in the bank for later.

Void · 2023-02-04 12:54:31

This is an interruption, so you may ignore it. But.......The other members are talking salts for storing heat just now.

Louis had this notion of power to gas on Ships.

I am wondering about a supertanker. Could you insulate it and fill it with molten salts. Then heat the salts at a place of renewable energy. Float the ship to a city, and power the city?

I don't know how practical that can be.

It is containerized thermal storage which is mobile and will allow heating at a place of advantage and can then move to a place of market for the energy.

Done.

Last edited by Void (2023-02-04 12:55:50)

SpaceNut · 2023-02-04 14:34:59

About 25% is useable in the high heat range before its solid once more but that leaves 75% of the heat energy at lower levels that salt is no longer in a melted condition.

These are values from the KRUSTY reactor design, but it applies to salt thermal storage in that the better that storage is for isolation the longer we can make use of that heat source.

Of course, you have the heat it's about the end use application requirements and for electric it needs that first 25% of that heat to create Stirling or steam generation heat into electrical.

After that is all liquid heating use to air or nonfreezing liquids for internal home use.

Void · 2023-02-04 16:43:30

Yes, according to markets of what is wanted.

But we might consider the combination of a Liquid Air Battery with a Molten Salt storage.

This may suit the Europeans rather well. The concept of Louis involved solar panels on a ship and a battery, I seem to recall. The notion is that you could sail it to somewhere sunny and charge up. That is a potential, but also, we might encounter international interference with that. There has been an effort to subjugate western peoples, and I don't like it. We have Judas Goats taking gold coin to facilitate that. My game is to curtail the slave trade, always. I have eyes on coastal North America as well, but I did mention the Judas Goats. Europe has had its feet to the fires and have fine people who have skills.

Now wind power to a combination Liquid Air Battery, and Molten Salt process on a ship.

It is closer in where NATO may help protect it, and there will be less opportunity for ethnic whining for tribute efforts.

Europe is to a large degree islands and peninsulas so ships can get to a lot of the big coastal cities.

Otherwise, wind is about undersea cables and then you have to store the power somewhere where for when the wind does not blow. This is mobile storage.

So, maybe not a bad deal for them.

And then later we will get it on our coasts. Our problem is that many on the coasts really have a need to hold the interior of the continent in contempt, and so may gladly suckle gold coins from the OPEC nipple, to sell us out. I don't think that the Europeans can afford that poisonous drink. And so, I hope to get what I want. The liberation of the western peoples from the slavers.

Done.

Last edited by Void (2023-02-04 16:51:06)

SpaceNut · 2023-02-04 23:33:54

Concentrated Solar Thermal: A Complete Guide

https://www.energy.gov/eere/solar/conce … wer-basics
https://www.energy.gov/eere/solar/conce … rmal-power
https://www.energy.gov/eere/solar/therm … wer-basics
https://www.energy.gov/eere/solar/dishe … wer-basics typically in the range of 3 to 25 kilowatts

https://www.solartronenergy.com/applica … centrator/

https://www.epa.gov/rhc/solar-heating-a … chnologies

https://builditsolar.com/Projects/Conce … rating.htm

https://georgesworkshop.blogspot.com/20 … intro.html

This one give 2 axis tracking

Terraformer · 2023-02-06 04:44:44

It may sound odd, but cold district heating is a thing. Basically it's a ground source loop to deliver seasonally average temperature fluid for use with heat pumps. Each building has its own and extracts whatever heat it needs.

Ground source heat pumps > air source, especially if we can inject heat in during the summer, but their application in Britain suffers due to most homes not having 700 m^2 of garden for a horizontal loop. This forces the use of vertical loop systems, which are expensive (~$20k for three boreholes?) and so beyond the reach of most households.

However, I suspect the high cost is driven by the fact they're hiring expensive equipment, moving it into tricky positions, and then using it to bore a mere two or three holes. The cost per hole should be a lot lower if, instead of a single garden, the holes were bored in a playing field. This ground loop could then serve hundreds of nearby homes. If the top 10-20m of the boreholes are heavily insulated, we would lose 1/3rd of the capacity as a fully *cold* system, but we would gain the ability to inject solar heat in during the summer (we need that much dirt to provide insulation). It would become an intermediate system, delivering enough heat for space heating without the use of heat pumps but not enough for hot water, which would be produced (at a very high CoP) using heat pumps.

There's a (roughly) triangle of land in my town (bordered by roads on three sides) that would be perfect for this. There's a primary school with a large playing field in the middle, the town hall, and various homes and businesses. All properties are adjacent to the playing field, so they could be connected to the heat field without having to negotiate easements. All the work could be done during the summer holidays to minimise disruption, and the two government(ish) buildings (school and town hall) could have solar thermal panels installed to provide heat for the system.

tahanson43206 · 2023-02-06 07:27:07

For Terraformer re #133

Thanks for showing what "Cold District Heating" is, and how it might work for your community.

For what encouragement from this forum might be worth, here is my endorsement!

Please let us know if you decide to pursue this with local personalities.

If you would like the forum to review text you might prepare for meetings, my guess is you'd find a supportive audience here.

There exists a form of non-interest financing .... It may have other names, but in the US it is called a repayable grant.

While the UK government may not have this financing method, the Monarchy may well have sufficient stored resources to be able to support a venture.

This might be a suitable topic for conversation with Prince William?

(th)

Terraformer · 2023-02-06 08:18:41

Well, the local council have talked about district heating (it's run by Greens; the trouble is that they generally aren't too good at the numbers side of things). I think the Town Council would be game also. And schools are facing big heating costs, so I'd expect good reception there.

As for the royals, we're within the Duchy of Lancaster. IDK how much the new Duke (Charles) has to do with its running; I hope he'll be as active as he was with the Duchy of Cornwall, which is now William's. Pretty sure he'll be down for it too.

An advantage of such seasonally boosted heat networks is that they can be improved in stages, if it's built correctly from the start. Firstly operated as a regular ground source heat pump system, then solar thermal can be incrementally added and used to inject heat, boosting efficiency. Likely in line with new users connecting to the system. It would act as a heat bank of sorts -- your rooftop panels would be metered as to how much you've put in, and this counts towards how much you pay for what you take out. European heating grids have managed to achieve unsubsidised costs of four eurocents a kWhr, so I expect it would be competative with where gas was a couple of years ago.

Now I just need to compose the email...

tahanson43206 · 2023-02-06 08:35:52

For Terraformer re #135

First, Bravo for your follow up!

Second, Dave Z in the Knowledge forum recently reported on a hot water distribution initiative in an Alaskan community where hot water is close to the surface. i bring this up because the practical activities involved seem (to me at least) to have some similarity to what you've proposed.

The long term investment by the Nation (and ultimately by the residents) ** should ** allow for reduction of expenditures for fossil fuels, assuming those are consumed by the residents for heating now.

Electric power production would be a stretch goal, but it seems to me it is not altogether out of reach. I think the key to this is to be first in the Nation to make the request for a repayable grant from the Crown, because those funds may be limited, and this venture might be approved as a demonstration.

(th)

tahanson43206 · 2023-02-06 11:20:10

For Terraformer ....

https://www.yahoo.com/finance/news/sask … 16490.html

Canadians show the way!

Financial Post
Saskatchewan company greenlights Canada's first large-scale geothermal power plant
Meghan Potkins
Mon, February 6, 2023 at 10:44 AM EST
DEEPEarth-0206-ph
Saskatchewan’s DEEP Earth Energy Production Corp. says construction will begin this year on Canada’s first commercial-scale facility for producing electricity from geothermal heat.
The privately held company announced Feb. 6 that procurement and engineering work has already begun on the 25-megawatt power facility in southeast Saskatchewan, close to the U.S. border, which will be built in two phases — supported in part by a five-megawatt power purchase agreement with SaskPower.
“We are a go,” said DEEP Earth chief executive Kirsten Marcia in a release. “There is a market that is hungry for truly sustainable, renewable power projects. The technology is proven, the leases are in place and initial government funding is confirmed.”
Construction and drilling will begin in the fourth quarter of this year, with the first electricity production expected by the summer of 2024. The facility is estimated to be capable of producing enough power for 25,000 households once it is complete.
DEEP Earth’s project will use oilfield-honed drilling techniques, with wells drilled to a depth of about 3.5 kilometres and horizontally for an additional three kilometres. Similar well designs are routinely used in the oil and gas sector, but application of these techniques to renewables is relatively new, the company said.
“Wells with equivalent depth, lateral length and step out are routinely drilled in the hydrocarbon resource plays of the Western Canadian Sedimentary Basin and DEEP will be leveraging this local knowledge and drilling capability,” it said.
Saskatchewan driller hits 'gusher' with ground-breaking geothermal well that offers hope for oil workers
Innovation Energy: The hot new fuel that could bring jobs and growth back to Canada’s oilpatch
The announcement represents a key turning-point for Canada’s nascent geothermal power industry which remains underdeveloped despite the country’s abundant potential.
DEEP Earth has been working to develop the project since it was founded in 2010. The company began drilling test wells in 2018 and has acquired the subsurface leases to support multiple power facilities capable of more than 200 megawatts of power generation. The company is also exploring the possibility of using some of its subsurface lease for carbon dioxide (CO2) storage underground.
More to come…
mpotkins@postmedia.com Twitter: @mpotkins

Note horizontal leg to gather heat! This technique could allow heat gathering to proceed under the entire town, and not just the field where drilling is done.

(th)

SpaceNut · 2023-02-06 19:46:33

The bore holes at depth send salt water into the well lines and returning back up as heated steam that is used to create power. News articles have indicated drilling many a hole to find the sweet spot to generate power from.

DEEP is positioned to move forward with the construction phase of a 25 megawatt power facility in southeast Saskatchewan, which includes a 5 MW power purchase agreement with SaskPower. The facility is planned to be constructed in 2 phases – 5 megawatts followed by an additional 20 megawatts at the same location. Production and injection wells are planned to be drilled to a depth of approximately 3.5 kilometres and horizontally for an additional 3 kilometres.
Marcia explained on that the footprint of the wells underground will be 6 kilometres east to west, and eventually 10 kilometres north to south once the later phases of the project are complete.
The surface facility will be a little north of where the principal test wells have been drilled. Both Phase 1 and 2 surface facilities will be on the same location, with underground, insulated pipelines connecting the wells to the facility. Those wells will be drilled from three to five surface locations.
These wells will be a lot wider than a typical oil well, with 9 inch well bores to the bottom, and 7 inch, specially lined tubing to combat corrosion. She explained that form of tubing is used in the oilsands, and is designed to handle high heat and abrasive material. It’s expected to last up to 30 years.
DEEP’s test wells set multiple records for the deepest wells drilled in Saskatchewan. They are at the deepest portion of the Williston Basin that falls within Saskatchewan, south of Torquay, approximately 3 kilometres north of the U.S. border. With geothermal energy, generally speaking the deeper you go, the warmer the energy potential due to heat from the centre of the earth.

https://deepcorp.ca/

Terraformer · 2023-02-07 08:08:49

Well, I've emailed a local councillor. The district council *should* be up for it, having declared a climate emergency and all, but their support, whilst very helpful, isn't actually necessary for this (the only support needed in the place I'm thinking of is the school, really). I think it would be possible for my town to disconnect from gas over the next few years if we get started soon. Maybe we could repurpose the gas pipes to extend the electricity network or something.

Getting Britain off gas by 2030 is achievable. I don't like having our quality of life tied so closely to international markets.

tahanson43206 · 2023-02-07 08:38:45

For Terraformer re #139

Thanks for informing us of your initiative ....

Your mention of gas lines to homes in your town awakened a question, so I asked Google:

You may be surprised to learn that the UK currently sources around 50% of its natural gas from its own territory, with the North Sea accounting for an estimated 50%. The remaining 50% of UK gas supplies are imported from various different countries around the world, including Norway, the United States and Russia.
Dec 2, 2022
Where Does the UK Get its Gas From? Official Statistics Explored
heatable.co.uk › boiler-advice › where-does-the-UK-get-its-gas-from

Since this is the Geothermal topic, I'll try to imagine how geothermal could be introduced without disrupting the convenience of existing heating services.

Geothermal cannot be used for cooking directly, so some means of converting geothermal energy to electricity would seem appropriate.

While exploration of geothermal options is going on, it would seem that residents in the area can continue to enjoy the benefits of natural gas.

However, I would think that dependence upon foreign suppliers would make folks in England nervous.

For that reason (as one of many) I would expect your initiative in contacting the local council to generate a positive response.

***
Unrelated to geothermal ... Dave Z in the Knowledge Forum said he'd seen a movie that included thatched roof houses. I can find the reference if you are interested. He offered the opinion there should still be a few folks in Great Britain who can maintain thatch roofs.

We were having a discussion about skills that are disappearing as the artisans who have them retire and no one takes their place.

(th)

Terraformer · 2023-02-07 08:50:45

Geothermal cannot be used for cooking directly, so some means of converting geothermal energy to electricity would seem appropriate.

I'm not suggesting we disconnect from the *electricity* network...

Though, you actually can cook with those temperatures. It's just that it wouldn't be worth the complexity for a home. A restaurant might consider it, however. A carvery perhaps? Gurdwaras could also be a customer for such a system.

~40% of our gas is presently used for domestic heating, so if we ended that use we would be close to sourcing all our gas domestically, with the remainder coming from Norway, a fairly reliable partner I'd say. If we increase our non-gas electricity sources as well we shouldn't need any imports at all.

Calliban · 2023-02-07 10:51:41

Terraformer wrote:

Geothermal cannot be used for cooking directly, so some means of converting geothermal energy to electricity would seem appropriate.
I'm not suggesting we disconnect from the *electricity* network...
Though, you actually can cook with those temperatures. It's just that it wouldn't be worth the complexity for a home. A restaurant might consider it, however. A carvery perhaps? Gurdwaras could also be a customer for such a system.
~40% of our gas is presently used for domestic heating, so if we ended that use we would be close to sourcing all our gas domestically, with the remainder coming from Norway, a fairly reliable partner I'd say. If we increase our non-gas electricity sources as well we shouldn't need any imports at all.

Cooking at low temperatures is a novel idea, one that is definitely worth exploring. This is the ultimate slow cooker. The link you provided suggested that botulism food poisoning can be avoided, provided that meat is heated to temperatures above 55°C within 4 hours. Presumably it would be completely safe to cook vegetables in this way. This idea is interesting, because if electricity becomes intermittent, tanks of water could be used to store heat and cook between temperatures of 50-100°C. Within this temperature range, water will store 58kWh of heat per cubic metre. This provides an interesting way of adapting to intermittent power supply.

Getting back to the use of low grade geothermal heat. The problem with heating using low temperature water, is that convective heat transfer rates are proportional to temperature difference. Radiative heat transfer is proportional to the fourth power of temperature. If room temperature is 20°C and your heating water tempedature is 30°C, then temperature difference is only 10°C. To get the same heat flux you need about 5x the heat transfer area as you would need if water temperature were 60°C. You also need higher water flowrates. Underfloor heating is a good way of achieving a large heat transfer area, but any tiling or carpet on top of it, will reduce heat flux even further. So in reality, you would need underfloor heating to cover about 10x the area that conventional radiators would cover. And it needs to be in every room that you want heated. Another option would be to put water pipes on the walls and plaster over them. That would work as well.

The bottom line is that to convert a house to low temperature space heating requires a lot of work. That is assuming you intend to heat the house to the temperatures that people have grown accustomed to. That doesn't mean that this isn't something we should be working towards. But I wouldn't expect this to be a rapid transition. It will take decades to bring the housing stock up to this standard, because we aren't talking about just changing the boiler. We are refitting the entire house.

Last edited by Calliban (2023-02-07 11:00:06)

Terraformer · 2023-02-07 11:31:42

Calliban,

Oh sure, the heat pumps will be with us for a while. But heat pumps + stored summer heat + water storage that lets us use nighttime power should still get us quite low heating costs. In the meantime, whilst waiting for the underfloor heating to be sorted, we can do things like moving our radiators from under the windows... or perhaps by using a means other than radiation to heat the room. Adding an additional heat exchanger to heat recovery vents, to further warm the incoming air, is an option.

The way I imagine the systems being built out, we would be operating ground source heat pumps initially anyway, possibly using summer air to get it up to ~20c from the normal ~10c. As more solar thermal panels are added to the network, the source temperature can be raised. It might not start delivering 40c water straight until a decade after being first built, by which point the houses will hopefully have been appropriately retrofitted to further reduce heating costs (raising the CoP for the heating network from idk 7 (20c -> 50c) to 20).

Last edited by Terraformer (2023-02-07 12:30:52)

tahanson43206 · 2023-02-07 11:44:26

For Terraformer re Town energy conversion initiative ...

Thanks to Calliban for post #142, with helpful perspective on what would be involved ...

The region where I live (in the US) has a mixture of land allocations. Your town is (probably) comparable to one of the subdivisions here.

A few subdivisions have strict building codes that are intended to preserve the historic nature of the area.

A few subdivisions are deteriorating and in need of massive investment to attract the younger home buyers.

Most subdivisions (as nearly as I can tell) are keeping up with maintenance, but not necessarily improving the property beyond where it was after construction.

I bring this up because your project/initiative may attract favorable attention, but naysayers are going to pop up in great numbers. That's just human nature.

We see it right in this forum, from time to time. Folks can't help themselves.

Here are a couple of suggestions that may or may not fit your vision ....

1) If you get an indication of interest in your proposal, you might invite the person to join the forum
2) My guess is that most active members of the forum would be willing to try to think through the details of a proposal that might be offered to city council
3) If you are thinking about tearing up the school playing field, it might be helpful to invite those responsible for that field to weigh in

Questions:

1) Are there any properties in the town that might be considered for a total replacement according to the model Calliban suggested?
2) Would it make sense to drill ** one ** well to see what the terrain is like below?
3) Are there any existing records to answer the question posed in #2
4) Are there any innovative, wealthy individuals willing to take the risk of funding an exploration project?

GoFundMe might be an option. I've never heard of an entire town running one, but it might work.

Something similar was (has been) used in the past to fund various versions of the Panama Canal, before the US put national capital to work to finish it.

If you are the FIRST community to try this, you might receive some early support that would not be available for later attempts.

Does your community have a newspaper that people still read?

Those seem to be going out of favor these days.

Perhaps there is a digital media version of the service that the home town paper used to provide?

(th)

SpaceNut · 2023-02-07 20:12:12

The heat pump uses the water or sand of the earth to save heat for later use these are not a geo thermal source as it's a created source.
Heat pumps are defying Maine’s winters and oil industry pushback

Whether you do a trench that is a couple feet wide and going to a depth of 4 to 6 feet is just one of the layouts that may be done with the horizontal layouts are at the same depth but have many hundreds of feet of tubing in the sand to save the energy from summer cooling for later.
Most of these system within the pump unit is a freon based heat exchanger unit that will use a liquid in the tubing to save that energy in the sand.

A vertical well needs to have a casing such that water within it does not go into the aquifer but stays stationary in it so that the exchange of heat is save for later.

Of course for the heating exchange we have air and then a radiant liquid system either within the flooring or as baseboard heating.

https://www.jlconline.com/how-to/hvac/p … nic-heat_o

The tubing diameter used, flow rate of the working liquid play into the drop in inlet going it to the return temperature leaving the zone or loop that once designs to.

That loop is typically a difference of 10 to 20 degrees F. from the temperature going in to heat the room up to the desired temperature.

https://www.pmengineer.com/articles/842 … tem-design

Calliban · 2023-02-08 18:06:07

The idea of low temperature cooking intrigues me. I looked up the cooking temperatures for various meats and vegetables. In the UK, there is actually a law that says restaurant cooked food must be served at a temperature no lower than 63°C. Vegetables require higher cooking temperatures than meat, paradoxically. Some will not cook beneath 80°C. There are waxes that melt at around 80°C and have a heat of melting about 60kWh per cubic metre.
https://brookotascreations.com/which-te … -of-waxes/

A house sized tank with good insulation, could store concentrated summer heat and use it to cook year round. Long term storage of heat works better with increasing scale. But a single cubic metre of wax will store sufficient heat to meet household hot water needs for several days. We could build communal bath houses or swimming pools that are heated year round by heat gathered in the summer and stored in hot water.

SpaceNut · 2023-02-08 20:20:33

https://millennialhomeowner.com/crock-pot-temperatures/

https://thesavvykitchen.com/crock-pot-temperatures/

Electric crock pots have a low and high setting for cooking food between 160 and 280 degrees Fahrenheit.

4 hours on low is the same as 2 hours on high
6 hours on low is the same as 3 hours on high
8 hours on low is the same as 4 hours on high

Terraformer · 2023-02-10 07:50:11

Some will not cook beneath 80°C. There are waxes that melt at around 80°C and have a heat of melting about 60kWh per cubic metre

My thinking immediately goes to (not terribly efficient) power generation with storage using a wax heat reservoir and an ice heat sink, relying on their latent heats. would have a theoretical efficiency of ~22%, so actual ~15%?

SpaceNut · 2023-02-10 21:16:18

Here is the typical hot water baseboard system for heating with multiple heating zones.

?url=https:%2F%2Fcdnassets.hw.net%2F31%2F66%2F52fac7f2457c9e80954341607e3e%2Fcomponents-of-a-hydronic-baseboard-system.JPG

The boiler will be replaced with a large holding tank and feeding that is the selected heat source. With a domestic hot water tank. Of course, we can do more by expanding the temperatures in either tank as well as the volume so long as we control the lose rates. It is also possible to make use of a sand battery as well to extend the heat duration as well.

The pipe size is mostly 3/4" for baseboard and there are some rules of thumb for how many feet are required to heat a room. A 1 ft section is able to on average output 450 to 550 btu of heat. That is what is required for every 18 sq ft of room area. It's going to be at a flow rate of 3.5 GPM with a in-to out temperature drop of 20'F. A boiler makes water in the 170-180'F range. So, to heat the room you will be in the 52 ft of baseboard at about a 75% efficiency from the boiler to get that rise in room temperature.
solar thermal heat gathered in summer can be stored in sand for winter use

eyJlZGl0cyI6eyJyZXNpemUiOnsid2lkdGgiOjcwMH19LCJidWNrZXQiOiJncmVlbmJ1aWxkaW5nYWR2aXNvci5zMy50YXVudG9uY2xvdWQuY29tIiwia2V5IjoiYXBwXC91cGxvYWRzXC8yMDE4XC8wN1wvMjQyMTE5MjlcL1NvbGFyIHRoZXJtYWwgcGx1cyBzYW5kIC0gUmFkaWFudGVjIC0gNC1tYWluLmpwZyJ9

Modeling results of sand-bed solar thermal storage
In the January-February 2011 issue of Solar Today magazine, David Sets, James T. McLeskey Jr. and Marshall Sweet report on the modeling and optimization of this system using TRNSYS. In their model, the storage was decoupled from the home (insulated on all sides). They will continue to monitor the actual project with thermocouples in the sand bed. Properly sized for a home, the modeling predicts 70% to 80% of the heat load can be provided by this.
Unfortunately the heating load of the home isn't described in the article, though a chart shows monthly demand peaking at 1800 kJ/m2/day (about 0.5 kWh/m2/day) during the coldest month.
I have collected quite a bit of information about these systems and I keep returning to the solution of super insulation first. However I think it might be quite good for something like a warehouse or big box store. Not necessarily economical though!

tahanson43206 · 2023-02-11 09:45:10

For Terraformer re #135

On the 6th, you appeared to be thinking seriously about composing an email to someone in your town political structure.

It may be too soon to inquire, but have you made any progress in composing the email.

I find that I often set bold actions like that aside for a variety of reasons, but I suspect the main one is the risk of being ignored (frequent result) or given a boilerplate response that someone in the staff was told to select from a pre-approved list.

The selection of a boiler plate response is most common here in the US, when a constituent writes to a politician. The general practice is to try to respond promptly to every constituent inquiry, but due to the volume of traffic, staff are instructed to make a best guess about what the constituent may have been asking, and then to send a pre-approved reply.

your situation may be different. for one thing, the government agency may be smaller, and you may even know (or have a chance of meeting) the official.

(th)

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#126 2023-02-03 07:55:15

Re: Geothermal and Geothermal Battery (Changed Title 12/21/23)

#127 2023-02-03 08:37:09

Re: Geothermal and Geothermal Battery (Changed Title 12/21/23)

#128 2023-02-03 19:14:03

Re: Geothermal and Geothermal Battery (Changed Title 12/21/23)

#129 2023-02-04 12:54:31

Re: Geothermal and Geothermal Battery (Changed Title 12/21/23)

#130 2023-02-04 14:34:59

Re: Geothermal and Geothermal Battery (Changed Title 12/21/23)

#131 2023-02-04 16:43:30

Re: Geothermal and Geothermal Battery (Changed Title 12/21/23)

#132 2023-02-04 23:33:54

Re: Geothermal and Geothermal Battery (Changed Title 12/21/23)

#133 2023-02-06 04:44:44

Re: Geothermal and Geothermal Battery (Changed Title 12/21/23)

#134 2023-02-06 07:27:07

Re: Geothermal and Geothermal Battery (Changed Title 12/21/23)

#135 2023-02-06 08:18:41

Re: Geothermal and Geothermal Battery (Changed Title 12/21/23)

#136 2023-02-06 08:35:52

Re: Geothermal and Geothermal Battery (Changed Title 12/21/23)

#137 2023-02-06 11:20:10

Re: Geothermal and Geothermal Battery (Changed Title 12/21/23)

#138 2023-02-06 19:46:33

Re: Geothermal and Geothermal Battery (Changed Title 12/21/23)

#139 2023-02-07 08:08:49

Re: Geothermal and Geothermal Battery (Changed Title 12/21/23)

#140 2023-02-07 08:38:45

Re: Geothermal and Geothermal Battery (Changed Title 12/21/23)

#141 2023-02-07 08:50:45

Re: Geothermal and Geothermal Battery (Changed Title 12/21/23)

#142 2023-02-07 10:51:41

Re: Geothermal and Geothermal Battery (Changed Title 12/21/23)

#143 2023-02-07 11:31:42

Re: Geothermal and Geothermal Battery (Changed Title 12/21/23)

#144 2023-02-07 11:44:26

Re: Geothermal and Geothermal Battery (Changed Title 12/21/23)

#145 2023-02-07 20:12:12

Re: Geothermal and Geothermal Battery (Changed Title 12/21/23)

#146 2023-02-08 18:06:07

Re: Geothermal and Geothermal Battery (Changed Title 12/21/23)

#147 2023-02-08 20:20:33

Re: Geothermal and Geothermal Battery (Changed Title 12/21/23)

#148 2023-02-10 07:50:11

Re: Geothermal and Geothermal Battery (Changed Title 12/21/23)

#149 2023-02-10 21:16:18

Re: Geothermal and Geothermal Battery (Changed Title 12/21/23)

#150 2023-02-11 09:45:10

Re: Geothermal and Geothermal Battery (Changed Title 12/21/23)

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