Comparative CO2 and energy: heat pump, gas and cpcu

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Comparative CO2 and energy: heat pump, gas and cpcu




by Christophe » 11/06/09, 23:24

Here is an excerpt from this subject of our dear captain, particularly synthetic and interesting, history to give the point on the i's about thermodynamic heating systems, presented as "miraculous" solutions.

Below, we have the comparison of 3 solutions:
a) gas heating
b) heating by advanced heat pump
c) district heating network heating by CPCU

Because what matters, in addition to CO2 is primary energy, EP in the text!

Capt_Maloche wrote:With a little bit of psychology :D , we can quickly explain that electricity generates more CO2 No, a little less that gas or fuel oil

500g of CO2 / kw.h useful (supplied) because in winter the peaks are supplied by oil and coal thermal power stations !!, the distribution efficiency remains poor after generation.

and the yield on EP is only 1 / 2.58 = 38% for nuclear

against 233g of CO2 / Kw.h for gas with yields of 97%

in addition, the savings made on energy consumption with the use of a heat pump is reduced to zero due to the short lifespan of this type of equipment which, after 8 to 12 years of operation, requires heavy interventions

I recently did an energy and environmental assessment for a project:
VRV = direct expansion system equivalent to a heat pump but more efficient
CPCU = Compagnie Parisienne de Chauffage Urbain (primary fuel: gas, heavy fuel oil, coal, household waste (yum) ...


Image
voili voilou
ERRATUM: Read 180kg of CO000 for the VRV instead of 2
Here is the table corrected following the muscular intervention below Image
Image

If like me you did not know the CPCU, district heating network, here are some technical explanations: http://www.cpcu.fr/index.php/cpcu/La-ch ... selon-CPCU

We use different sources of energy to produce heat:

* energy recovery from waste, which is the primary source of heat distributed by our network
* gas in cogeneration and in boilers,
* finally, coal and fuel oil in the other CPCU production centers.

Image



The high proportion of household waste probably explains the low value of 195 g of CO2 per useful thermal kWh!

Edit Capt_maloche 05/08/2009
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by yannko » 12/06/09, 09:30

Very interesting subject, thank you Christophe and Captain for this info.
What are the labels in the table (certain lines with coefficients or proportionalities, what do they represent?).

By way of comparison, in the Czech Republic, cogeneration for district heating is well developed, due to the presence of numerous thermal power stations, almost everywhere (smaller units, but which supply a local town or village).
In Prague, it is possible to access it in almost any district. Mainly, it is coal, gas power plants, an incinerator (fairly clean, the chimney is the highest in the country), and district boilers that supply DHW and heating.
On the other hand I did not manage to find much information on the difference between a steam distribution, or a hot water distribution. There are building / house boilers for both solutions, but I have no more information on them. Anyone have a doc?

I find that this mode of heating is very interesting in town, much less generator of surface and atmospheric pollutants, the prices are relatively stable, and one risks much less the cut of heating from the whims of such or such country. And it's still a great point to recover the calories used to generate electricity, rather than simply wasting them.

By cons, I do not understand the owners and contractors of real estate, all new housing that I visited, located near a heat distribution network, was generally never connected to it :|, and very often used a high power gas boiler for the entire building.
Personally, I find it very unfortunate, since you can have your personal meter for the energy consumed, and you still get rid of heavy work, and you benefit from increased security (no gas pipes, oil boiler to revise, ...).

For the curious :D :

www.ptas.cz/en_uvodni_stranka/
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by floflo87 » 29/07/09, 10:51

Hello,

What annoys me about the manufacturers, whether PAC or otherwise, is their bad time, the fact that they use the numbers as it suits them ... but hey that's what makes them make a living so we can understand / forgive them.

But what annoys me even more is the bad times of the "anti", and obviously here the anti-PAC !! The CAP has these flaws and advantages, but to give such outrageous figures is incredible.

Here's why:

1 / Never the efficiency of a GAS boiler will be permanently 109%, it is at best the RATED efficiency which is only rarely reached.

2 / Today, most of the heat pumps have COPs greater than 3 (why take the maximum for the gas boiler and not for the heat pump ??), but again this is a nominal COP given for a outside temperature of + 7 ° C. However, if this COP decreases with temperature, it also increases with it. Assessment, the seasoned COPs are therefore often greater than 3.

3 / Finally, the figure of 500gCO2 / kWh is completely wrong! Add to this a calculation which is also false and we obtain an aberrant value ... shame on the author ...
In the table, if it takes 1080000kWh / year to heat, we only consume 1080000/3 = 360000kWh electricity with the heat pump. We can then multiply this figure by the (false) coefficient of 500gCO2 / kWh to finally obtain 180000kgCO2.Instead of the 464400 which is obtained by multiplying 180000 by 2.58, but which has nothing to do in this calculation !!! : Shock:
In addition, in France the average kWh of electricity rejects 84gCO2 (much more for certe thermal power plants, but much less for nuclear and hydroelectricity! ADEME figure). We then obtain only 30240kgCO2 or reduced to the surface 3.4kgCO2 / m².year.
On the other hand if we have less CO2 we have more radioactive waste (but fortunately not both), and there it is another debate ...

I hope I have been understandable, and have brought some clarity to the subject. Hoping that people who have read this topic before, were critical enough not to be bamboozled ... : Evil:
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by Christophe » 29/07/09, 11:23

floflo87 wrote:I hope I have been understandable, and have brought some clarity to the subject. Hoping that people who have read this topic before, were critical enough not to be bamboozled ... : Evil:


I think there is indeed an excess at the level of 500 g of CO2 / kWh, moreover there is a confusion since it multiplies kWh EP and kWh useful ... not good therefore!

Logically, we should be at 540 / COP = 000 / 540 = 000 kg of CO3 for the heat pump (= kWh need * 180 g). But these 000 g are "overvalued" for France unless the heat pump is exclusively supplied by a coal or fuel oil plant ...

In Germany for example, the reasoning would be good since the emissions are 600 g CO2 / kWh ...

For EP, on the other hand, it's good: in Primary energy, a heat pump is at the same level as a boiler ... unless this heat pump was powered by cogeneration (still far too rare ...).

I leave it to Maloche, author of the reasoning within the framework of an engineering project, to give you a proper answer ...

Otherwise, as you seem to know yourself in PAC, do you have COPA figures? Concrete and real?
Last edited by Christophe the 04 / 08 / 09, 23: 55, 1 edited once.
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by floflo87 » 29/07/09, 12:22

Christophe wrote:In Germany for example, the reasoning would be good since the emissions are 600 g CO2 / kWh ...


Indeed, French electricity production is quite specific

Christophe wrote:For EP, on the other hand, it's good: in Primary energy, a heat pump is at the same level as a boiler ... unless this heat pump was powered by cogeneration (still far too rare ...).


it will mainly depend on the type of PAC. If it is a heat pump on air, in fact the two are of the same order. On the other hand, if we start on a geothermal heat pump, the COPs are greater than 3 and the problem of the temperature decrease is almost zero thanks to the fact that the ground temperature is almost constant

Christophe wrote:Otherwise, as you seem to know yourself in PAC, do you have COPA figures? Concrete and real


This is precisely one of the reasons for my visit to this forum. In fact, I am carrying out (well, I am trying) a study aimed at comparing the elec heat pumps and the gas heat pumps. But getting serious numbers is particularly complicated. So I don't have precise figures, but just "trends" thanks to the various readings and discussions that I have had on the subject. I hope to be able to launch computer simulations soon, but it will remain a simulation based on calculation hypotheses ...
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by jlt22 » 29/07/09, 15:31

Hello,
Here is a link concerning gas heat pumps:

http://www.gaz-naturel.ch/fr/applications/pac-gaz.html

Another clarification, French electrical energy emits on average
145 Kgs of CO2 per MWh, the average European electrical energy
emits 373 kgs of CO2 per MWh. (source echoes):

http://www.lesechos.fr/depeches/science ... 170202.htm

Perhaps we should consider the latter to make comparisons, to take into account consumption peaks, given that all European networks are interconnected.
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by Capt_Maloche » 04/08/09, 23:48

floflo87 wrote:Hello,

Here's why:

.......

I hope I have been understandable, and have brought some clarity to the subject. Hoping that people who have read this topic before, were critical enough not to be bamboozled ... : Evil:


well no Image not being bamboozled is important indeed, point by point answers

This comparison covers a period for a heating season in the Paris region, from September to May

1 / Never the efficiency of a GAS boiler will be permanently 109%, it is at best the RATED efficiency which is only rarely reached

The comparison is done on a low T ° network, the boiler efficiency will be close to the maximum (besides I should have taken 102% for the regulation efficiency, but we are not at 5%)

2 / Today, most of the heat pumps have COPs greater than 3 (why take the maximum for the gas boiler and not for the heat pump ??), but again this is a nominal COP given for a outside temperature of + 7 ° C. However, if this COP decreases with temperature, it also increases with it. Assessment, the seasoned COP (rs) are therefore often greater than 3.

In this comparison it is a VRV with an air / refrigerant exchanger (not a heat pump whose average annual yields tend to tend towards 3 and this under the best conditions ie at low T °) whose maximum COPs are 4.5 and the average annual COP measured in the field (in heating mode, the one that interests us, from 3, source DAIKIN and Eurovent)
The average maximum COP of 3 is therefore taken into account in this comparison


3 / Finally, the figure of 500gCO2 / kWh is completely wrong! Add to this a calculation which is also false and we obtain an aberrant value ... shame on the author ...
In the table, if it takes 1080000kWh / year to heat, we only consume 1080000/3 = 360000kWh electricity with the heat pump. We can then multiply this figure by the (false) coefficient of 500gCO2 / kWh to finally obtain 180000kgCO2.Instead of the 464400 which is obtained by multiplying 180000 by 2.58, but which has nothing to do in this calculation !!! : Shock:
In addition, in France the average kWh of electricity rejects 84gCO2 (much more for certe thermal power plants, but much less for nuclear and hydroelectricity! ADEME figure). We then obtain only 30240kgCO2 or reduced to the surface 3.4kgCO2 / m².year.
On the other hand if we have less CO2 we have more radioactive waste (but fortunately not both), and there it is another debate ...


HOULA!
I did not invent this figure, far from it
it is a value that makes a lot of hay at EDF and plays into the hands of competitors like the CPCU, and yet it may soon be announced (unless political pressure or lobbyist)

It is true that the coef of 2.58 has nothing to do in the calculation if we use the Quantity of CO2 produced for 1 KW.h on the meter (I corrected the table following your intervention, thank you anyway) and therefore that the good result on the basis of 500g is 180 kg of CO000, I know how to recognize an error.

As you say, the "AVERAGE ANNUAL" value of CO2 production is fairly moderate for electricity generation in FRANCE over the year, thanks to our power stations; but it is another kettle of fish in winter when all the coal and oil thermal power stations are running at full speed to meet the needs with much worse returns than nuclear power, not to mention the importation of foreign energy ... !! !

it follows that over the heating period from September to May, the results are catastrophic (I am looking for the curves and the supporting documents that I do not have under the elbow)
Image


You are still right on one thing, Geothermal heat pumps have better yields due to a relatively stable T ° of the subsoil

But unfortunately, the cost of energy is not important enough to amortize the purchase of a heat pump over 10 years of operation compared to gas for example, where the purchase price of a heat pump is worth 3 times the price of a boiler and we know that the life of a heat pump rarely exceeds 10 years.
Last edited by Capt_Maloche the 05 / 08 / 09, 18: 00, 1 edited once.
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by Christophe » 05/08/09, 00:01

I quite agree with your answer except this:

Capt_Maloche wrote:it follows that over the heating period from September to May, the results are catastrophic (I am looking for the curves and the supporting documents that I do not have under the elbow)


Ben that they are higher than the 90 g / kWh, we do not doubt it but they test the 600 gr / kWh of Germany (50% of coal electricity, as a reminder), I doubt it ...

So obviously it can happen in a very specific district supplied all winter by an oil or coal thermal power station (it was maybe the case of your study?) But we cannot say that France emits 500 gr / kWh in average over the winter months ...
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by Capt_Maloche » 05/08/09, 00:23

Do you believe !!

This figure takes into account (to be checked as soon as I have the data at hand, at the office) the extraction, transport and enrichment of uranium which is not a "fossil" energy exploitable in the state

Besides radioactive pollution of air, soil and water by nuclear power plants, uranium enrichment plants, fuel fabrication plants, fuel reprocessing plants and transport of substances radioactive (these contaminations are easy to measure and can be reduced to very little, but negligence is frequent, subcontractors are not always well trained and well monitored, and all at a high cost, which is tempted to reduce when you have to be competitive!)
Thermal pollution of running water (except by the sea); in the event of a drought or heat wave, cooling of the power stations becomes impossible: they must be stopped!

Overabundant energy production, which hinders the development of renewable energies, maintains the illusion of indefinite growth and encourages waste (while energy savings have become vital and nuclear power is and will remain a minority in the coverage of our energy needs) finally, I wish
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by Capt_Maloche » 05/08/09, 00:26

It's not mine, but the debate has been around for a long time

Nuclear energy produces CO2 and contributes to the greenhouse effect. It will produce more and more as the content of uranium ores gets lower and lower.

In the production of electricity from nuclear power plants, we must not limit ourselves to the last step, which does not produce CO2, but take into account the entire sector from the extraction of the ore.

In surface mining, this extraction uses backhoes and trucks, with impressive dimensions and the consumption of petroleum products commensurate with these dimensions. In underground mines, the result is identical with other means. Crushing of this mineral uses the same CO2-producing energies. Transportation from the mines, by trucks or by trains with diesel locomotives, then by sea does the same.

The subsequent stages also use a large amount of energy, whatever the source.

In total, each kilogram of uranium oxide used in a nuclear power station required considerable quantities of fossil energy for its production. This consumption produces CO2 in proportion and this is why nuclear energy also emits CO2.

At present, with the richest minerals (high uranium content), the use of fossil fuels is still moderate. But this consumption increases as available minerals have an increasingly low uranium content. To obtain the same amount of uranium oxide, you will need to consume two, then ten ... times more fossil energy by producing two, then ten ... times more greenhouse gases (CO2).

Ultimately, the same amount of electricity produced by a nuclear power plant will produce more CO2 than a natural gas power plant.
Last edited by Capt_Maloche the 05 / 08 / 09, 00: 38, 1 edited once.
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