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bernardd
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by bernardd » 30/08/10, 23:41

Addrelyn wrote:
bernardd wrote:What do you think is the share of electricity used for heating and hot water? This figure must exist somewhere, right?

I have not found better than that
http://www.statistiques.equipement.gouv.fr/IMG/pdf/20_ans_de_chauffage_dans_les_residences_principales_en_France_de_1982_a_2002_cle1c42ed.pdf
Already it gives an idea even if the document dates from 2002.
After a little calculation: 4Mtep * 11 = 600 TWh


This seems totally undervalued to me, because these are only main residences: all the non-residential is missing!

But already it would be equivalent to exports.

Let's try another approach: RTE publishes very nice curves and forecast methodology document.

The following elements can be seen on page 1 and 2:

- the annual cycle shown is consistent with an annual domestic consumption (NB different from final consumption) of 494TWh, which represents an average of 9500GWh / week.

By eye, the minimum is 6500 in August, and the maximum at 11500GWh.

We see a plateau between weeks 19 and 40 (May to September), which in my opinion corresponds to consumption in the absence of heating, which are then at 7500GWh / week. On the basis of this observation, the internal consumption without heating would be 7,5x52 = 390TWh, which would bring back to a final consumption of 347TWh, keeping the share of final consumption compared to internal consumption (89%).

This would correspond to a final consumption of electric heating of 93TWh (= 440-347), corresponding to a nuclear production of 111,6TWh (= 93x1,2).

This estimate is rather underestimated, because the consumption of air conditioning and the consumption of electric domestic hot water should be removed from the summer value.

According to this estimate, electric heating represents 21% of current final electricity consumption. But it represents an increase of 26% compared to the "noble" final consumption.

Using direct thermal solar (thermal collectors) and indirect solar (biomass) for heating, we could eliminate 10 nuclear power plants of 1450MW.

At the same time, the need to produce 347kWh of electricity for "noble" use would be greatly reduced and more accessible to renewable energies.


By the way, we see that the daily cycles of electric consumption go from 35GW to 53GW in summer, and from 67GW to 87GW in winter.

The average energy per week of 9500GWh / week corresponds to an average power of 56GW.

The energy per summer week of 7500GWh corresponds to an average power in summer of 44,6GW.

The energy per winter week of 10500GWh corresponds to an average power of 62,5GW, i.e. an additional energy per week of 3000GWh, corresponding to a supplement of 17,8GW of average power in winter.

It is consistent for the summer, but the winter day curve should be for a cold week.
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by bernardd » 31/08/10, 01:04

Addrelyn wrote:
bernardd wrote:In other words, if we imagine that each of the 30 million dwellings has an identical electric generator, what should be its average power? And then its minimum power and its maximum power?

If I take up the idea of ​​your calculation, (well I think). We remove the electric heating and exports, there remains 475TWh to produce.
There are around 25 million households according to INSEE (say 26.5 if their projections are correct)

http://www.insee.fr/fr/themes/document. ... =0&id=1941


"As of July 1, 2007, the stock amounts to 32,5 million housing units in metropolitan France and in the overseas departments."

I was leaving on 30 million to simplify the calculations.

According to the previous post, a final consumption of 347TWh excluding electric heating and export corresponds to an annual production per household of 11MWh, which corresponds to a weekly production of 211kWh, a daily production of 30kWh, and an average power of 1,25kW.

With a daily power varying from 35GW to 53GW, this corresponds to a production power per dwelling varying between 1kW and 2kW, which is consistent with an average of 1,25kW.

To have an easy to grasp reference, the annual production of 11TWh corresponding to a 1450MW nuclear power plant corresponds to a power of 42W in 30 million dwellings.

Is it possible to have an electric generation with a power varying between 1 and 2kW in each dwelling?
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by bernardd » 31/08/10, 08:46

Are you all right?

Do you think we have reached the end of the savings on "stupid electricity"?

We estimated the importance of silly electric heating by making the difference between summer and winter consumption, but what about silly electric consumption to heat water?

How much energy does it take to heat water? It is an eminently historical question, because it corresponds to the awareness of the physical concept of energy, with the definition of calorie.

We find here :
The calorie is a unit of energy. It was defined by the chemist and physicist Nicolas Clément in 1824. The term appears in French dictionaries from 1841 and in English dictionaries from 1867. It was proposed and used long before Joule established heat equivalence -work (1843). ....
Its historical definition indicates only that the calorie is the quantity of heat necessary to raise by 1 ° "centigrade" the temperature of 1 kilogram of water. The definition of calorie is therefore based on the heat capacity of water.


Today, we write that heating 1kg of water to 1 ° C requires 4186J of energy, which also translates into 1,163Wh.

For 1kg of domestic hot water at 60 ° C obtained from cold water at 10 ° C, a difference of 50 °, we therefore use 58Wh = 209kj of energy, or even 58kWh for 1m3 heated to 10 ° C at 60 ° C.

Now it seems that "One person consumes 55 m³ annually, including 18 m³ of domestic hot water".

And without counting industrial hot water.

This corresponds to an annual consumption of 1044kWh, or 62,64TWh of final consumption for 60 million inhabitants, and adding the losses of 20%, 75TWh to save on domestic consumption: another 6,75 nuclear plants of 1450MW less .

We stayed at a final consumption of 347TWh excluding electric heating and export, we now arrive at 285TWh of final consumption, excluding heating, hot water and exports.

Heating (93TWh) and hot water (63TWh) together represent 156TWh of silly electricity, or 35% of current final consumption: I was far below the mark taking 25%!

Addition: As Addrelyn pointed out to me (1 point!) Started in my tracks, I forgot to remove the share of non-electric domestic hot water, which I do not know anyway. We will then approach 25% of my intuition: -? Too bad, it will count for the idiotic uses that we have not yet identified! / Addition

More this represents a 54% increase over what final consumption should be without silly electricity!

This amounts to an annual production per dwelling of 9,5 MWh, or an average power of 1,08 kW of production per dwelling.


By stopping consuming stupid, we could stop :
- 5 plants for export,
- 10 power stations for heating,
- 6,75 plants for hot water,
or, 21,75 1450MW power plants! or 25,3GWp of peak nuclear power.

But there are only 4 plants at 1450MW, but 34 plants at 900MW: we can delete 28, keeping only 6 900MWp power plants, 20 1300MWp power plants and 4 1450MWp power plants.
Last edited by bernardd the 31 / 08 / 10, 15: 40, 1 edited once.
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by Christophe » 31/08/10, 09:00

bernardd wrote:Do you think we have reached the end of the savings on "stupid electricity"?


Go tell that to the ADEME which advocates geothermal heating ... : Cheesy:
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by bernardd » 31/08/10, 10:26

We now know that excluding silly electricity (heating and electric hot water), final consumption is 285TWh.

Keeping centralized production, add 7% of losses and adjustments, reaching 305TWh. With a more distributed production, we can also reduce these losses: let's start on 300TWh, it's simpler :-)

Electricity production from renewable energies is currently 75TWh (statistics_France_2009no_liaison_cle5b24c7-Complété.xls), i.e. 25% of the target domestic consumption: remains to be produced 225TWh.

I favor for the moment 2 processes:
- photovoltaic ;
- cogeneration from biomass combustion.

Page 2 of this EDF document, we can now have 140Wp / m2, with a duration equivalent to 100% varying from 2h / d or 730h / year in chtis, to 4h / d or 1460h / year in the south.

Starting on 1000h / year on average, 1m2 or 140Wp will produce 140kWh / year on average, ranging from 102kWh / year to 204kWh depending on the latitude.

But this local production does not cause any loss, while a nuclear power plant creates 20% loss at least. On the other hand, a nuclear power plant produces longer:
In passing, it can be noted on page 24 that 59 nuclear units represent 63,2GWp, or 1,07GWp / unit, to produce 439TWh, or 6946Wh / Wp and 7,44TWh per unit.


In summary, to produce 102/140 / 204kWh corresponding to 1m2 of solar, a nuclear power plant must produce to take account of its losses: 122/168 / 244kWh and use for this a capacity of 17/24/35 Wp.

Add:

I had initially put:
A 1300MW nuclear power plant is 0,037142km2 or 3,7ha in the South, 0,76470km2 or 7,6ha in the North, and 0,054166km2 or 5,4ha on average.

But as Addrelyn pointed out to me (+1 point :-)) this is false.

It would rather be:

A 1300MW nuclear power plant has an area of ​​photovoltaic panels of 37km2 in the South, 76km2 in the North, and 54km2 on average.

Per dwelling, this represents 1,3 / 1,8 / 2,6m2 of photovoltaic panels, or 0,3 / 0,5 / 0,6m2 of thermal panels.

/ Addition

How much is the area of ​​a power plant? What about the surfaces of uranium mines and factories for the concentration of uranium, and the reprocessing and storage of nuclear waste?

Based on the final annual consumption per dwelling, estimated at 9,5MWh, it takes 93/67 / 46m2 of photovoltaic energy per dwelling to produce all the electricity needed in France: rather reasonable!

In the absence of sun, it is necessary to develop a production by cogeneration based on biomass: starting on a cogeneration machine producing 1kW from 10kW of thermal production by combustion of biomass (i.e. 2kg of wood pellets for example) , an electrical efficiency of 10% fairly easy to obtain, it would be necessary to burn 95000kWh to obtain 9500kWh of electricity and 66500kWh of heat (with 20% of thermal losses of combustion), which corresponds to 19t of biomass per dwelling to produce all final electricity consumption in France.

The target will obviously be a mix between photovoltaics, biomass cogeneration and wind power: we would have to start by analyzing the RTE measurements to relate the hourly production to the sunshine.

I have the feeling that photovoltaics can represent 50% of final electricity, wind and biomass cogeneration consumption, each sharing a quarter:
- 46/34 / 23m2 of photovoltaics per unit to produce 50% of the electricity needed in France;
- 5t of biomass per dwelling to produce 25% of electricity in France and a large part of the heat;
- and the rest in wind, for which I do not know the production statistics by installed peak power.

Without forgetting thermal solar to complete the cogeneration of biomass for heating and hot water.


NB: there must be errors in all these calculations, it's up to you to find them :-)
Last edited by bernardd the 31 / 08 / 10, 15: 49, 1 edited once.
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by sen-no-sen » 31/08/10, 11:27

Very interesting calculations bernardd,hat!

After it must be seen if this is applicable in large cities, because solar or biomass would be difficult to establish there, but for the individual house it sticks.
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by bernardd » 31/08/10, 11:39

sen-no-sen wrote:Very interesting calculations bernardd,hat!

After it must be seen if this is applicable in large cities, because solar or biomass would be difficult to establish there, but for the individual house it sticks.


Thank you :-) These are orders of magnitude. But cities have a lot of flat roofs, I don't think there is a problem, apart from perhaps the air pollution which intercepts solar radiation?

Otherwise cities have less natural biomass, but they have more waste :-)
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by sen-no-sen » 31/08/10, 11:48

We are a bit off topic ... : Lol:

In the city, or in peri-urban areas, the ideal would be to make biogas with human biological residues (... excrement), a technique that is developing a lot in China.
Burn our waste ... provided that it is based on biodegradable materials (industrialists have jobs).
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by bernardd » 31/08/10, 12:22

sen-no-sen wrote:We are a bit off topic ... : Lol:


So last post :-) but it's all about replacing nuclear : Cry:

sen-no-sen wrote:In the city, or in peri-urban areas, the ideal would be to make biogas with human biological residues (... excrement), a technique that is developing a lot in China.


To arrive at 5t of biomass per dwelling, it is an imperative, without counting the gain on water.

But I think that the transformation into storable granules, after drying, is much more efficient than fermentation.

sen-no-sen wrote:Burn our waste ... provided that it is based on biodegradable materials (industrialists have jobs).


Anyway, they are burned today: to do it on a small scale, you have to eliminate the nitrogen by concentrating the oxygen in the oxidizer:
- We avoid all NOx pollution,
- the flame temperature is increased, which burns everything more efficiently, without dangerous unburnts,
- we recover pure CO2 which we can reuse,
- and the higher temperature improves the electrical efficiency of cogeneration.
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by Remundo » 31/08/10, 12:22

We are not that HS ...

What alternatives to all nuclear (or even all oil)? We realize that it is perfectly playable with modern technologies, such as PV, wind turbines, inverters ...

And products "of the past" and paradoxically to come because neglected because the market has been broken by oil and nuclear.

Like Stirling cogeneration with wood.

In the 30s, the Stirlings were more developed than now! They were used to power radios in particular, wherever electricity and heat were useful, microstirling were usable ... Then electrochemical cells, large coal-fired electricity networks supplanted them

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