General > General Technical Chat
What is the real story around heat pumps?
Miyuki:
--- Quote from: zilp on February 21, 2024, 10:38:49 pm ---
--- Quote from: Zero999 on February 21, 2024, 08:49:56 pm ---
--- Quote from: zilp on February 21, 2024, 08:27:15 pm ---That seems contradictory? If nuclear is supposedly cheap electricity, then why would the government have to invest in it? Especially when increasing demand is expected with more heat pumps being deployed, why would it need the government to provide the investment for that cheap electricity?
--- End quote ---
If the goal is to reduce carbon emissions, then investing in nuclear power, so we have cheap electricity, is a no-brainer. Nuclear plants have a high upfront cost, which few private investors are wiling to pay,
--- End quote ---
Hu? Where did you get the idea that few private investors are willing to pay high upfront costs with almost guaranteed returns?! I mean, unless you mean "few" as in "most individual people don't have the money to pay for a nuclear power plant"?! I mean, BlackRock have 9 trillion USD of assets under management ... they certainly could find a bunch of people among their clients who would have the cash to build a nuclear power plant and would be willing to do so for reliable returns!? Sounds almost ideal for pension funds! And they obviously aren't the only large asset managers out there.
My best guess is that what you've heard is that few private investors are willing to fund high upfront costs with significant risks. Like, funding billions for medical research where there is a significant chance that nothing comes of it. Which is true. But that is because of the risk, not because of the high costs. And if there is significant risk, then that is exactly the contradiction that I was talking about: How can a nuclear power plant be both a reliable cheap source of electricity (which thus would have reliable long-term returns, if you own the power plant that can produce power cheaper than everyone else) and at the same time a high-risk investment that would need the government to step up?
--- Quote from: Zero999 on February 21, 2024, 08:49:56 pm ---so it make more sense for the government to invest in it, rather than wasting money on other green schemes such as heat pumps and banning internal combustion engine vehicles.
--- End quote ---
Why do you think that that is wasting money?
--- Quote from: Zero999 on February 21, 2024, 08:49:56 pm ---Given cheap, clean, electricity, people will voluntarily switch to heat pumps and electric cars, without subsidies or banning anything. It will also boost the economy, in the form of reduced energy costs to businesses.
--- End quote ---
Well, that much is obvious, yeah.
--- Quote from: Zero999 on February 21, 2024, 08:49:56 pm ---Nuclear power will see a return on investment, in the long term.
--- End quote ---
That part though ... your arguments certainly don't support that conclusion.
--- End quote ---
Nuclear power has a big problem, you have those same crazy dudes glued to the road also protesting against nuclear.
And as there is no economy of scale nowadays, the cost is enormous.
Current builds will be profitable in 30-40 year horizont (if there won't be any problems). So no investor will go into this because it is beyond their lifetime and when you have investment opportunities with orders of magnitude higher returns. And even after that 30-40 years, those profits are not that great.
And even governments are reluctant because it is controversial, because of those factors.
pcprogrammer:
--- Quote from: Siwastaja on February 21, 2024, 07:34:58 pm ---Never heard about De Dietrich. It's probably just some label on some Asian product, like 90% of heatpump brands (including "German" brands like Bosch). Many heatpumps are label over label over label.
--- End quote ---
De Dietrich is a very old French brand. At some point it joined ventured with Remeha a Dutch brand. I have no idea where the pump offered is fabricated. The reviews seem to be good and put it up at the top with Daikin and Mitsubishi.
--- Quote from: m k on February 21, 2024, 07:36:53 pm ---Do not use RS-485 for long distances, put a converter near the pump, or an isolator.
Yes, it's made for that, but you do not want that the pump side fails.
With luck you have a machine with multiple circuit boards, but it's a monoblock.
With bad luck there's only one PCB and the driver is integrated to MCU.
--- End quote ---
My system has provisions for UART with optical isolation. This coupling will be very close to the pump unit. For what I found on it, it is bog standard RS485 and used to connect their brand thermostats. It will be protected against things like lightning to some extend.
pcprogrammer:
--- Quote from: Zero999 on February 21, 2024, 07:46:11 pm ---
--- Quote ---Still waiting for the second quote, but in the mean time I have found options for controlling, or at least read the De Dietrich heat pump with a RS485 interface. A lot of the info is in French, and unfortunately registering to the before mentioned site did not result in the ability to download the mentioned files. But I found a github repository with a python based solution, which gives the needed information.
--- End quote ---
Are you sure it's a good idea to get something which isn't very well documented? Going by what you've said, that company could be a pain to deal with.
--- End quote ---
I'm not afraid of a bit of research. If needed reverse engineering is a way to go. The whole thing will become a big experiment to reach a solid and economical solution.
Zarhi:
That's is situation with air source heat pumps from this morning:
Outside temp 2°C, humidity about 60%, clear sky, no rain, no clouds, no fog.
Pictures taken 3-4 minutes after defrost cycle completion.
Anyway in the morning inside temperatures was:
First floor: bedroom - set 22°C, actual 22°C, living room set 24°C, actual 25°C.
Second floor: two bedrooms - set 22°C, actual 23°C.
Last 10 hours electricity consumption: 12kWh
tszaboo:
--- Quote from: Someone on February 22, 2024, 02:16:37 am ---
--- Quote from: tszaboo on February 21, 2024, 10:34:44 pm ---
--- Quote from: Someone on February 21, 2024, 08:33:57 pm ---Again with your pushing of solutions and completely ignoring/side stepping the practical ones (pretending like no other options exist).
Oversize the solar array, then it will produce enough energy in winter.
Sure not everyone has the physical space for that, but few have the physical space for ground source thermal storage/dissipation.
--- End quote ---
Almost nobody has place for that here. I have a system that covers my yearly electricity consumption, in fact makes an extra MWh. And I needed 5 GJ heat this december, which is 1400KWh, while my solar made 52KWh, which is a factor of 27. Even with SCOP of 5, it's just not going to be worth it to install 6x the solar on my roof, no space, no money for it.
--- End quote ---
Which you know... I said (and you quoted). The size of that setup is comparable to the sustainable footprint ground source heating in those cold places where little to no air-conditioning is needed (and solar production falls way off in winter).
Why go straight to extremes with a pure solar setup? its a convenient strawman? Energy supply is almost always cheapest as a mix of things.
Sizing solar arrays to the inverter or export limit is old thinking. Panels are cheap and adding more capacity (vertical for winter production for example) can be cost effective for many.
Also to be pedantic you don't need 5 GJ of energy for heating, you want 5 GJ of energy for heating. That's a choice and how you supply it is up to you (and you can pay for it).
--- End quote ---
I'm a bit confused, in one comment you say we should oversize solar system to cover winter energy needs. When I show you it's not practical, you say that's not what you said. So then what is your suggestion?
And yes, I do need 5GJ for a winter to be bearable in my home, dropping temperatures lower than most people keep here would be a respiratory hazard. To be pedantic, I don't really care about global warming and polar bears, if I cannot keep temperatures at home high enough to live a quality life. And if the government has a problem with this, we'll overthrow the government and bring out the guillotines for good measure.
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version