Granulated or aerothermal boiler house project

[bernardd]

Hello !

With pellets and solar, I have 67% of off-peak hours (which I will delete) saved and 17% of full hours less, or 40% of the total.
Not possible with heat pumps ...

Thank you, very interesting! In addition the site indicates that you are in Lorraine, so no need to be south of Valence to do solar :-)

Can you describe your installation a little more and the consumption figures, please?

Are you talking about photovoltaic or thermal solar?

[manet42]

Hi,
Visible on this site:
http://www.chaleurterre.com/forum/viewt ... 9dbe88392c
For consumption.
Forecast before installation:
4,5T of granules; of 2000kwh solar (www.valentin.de) to 5 (very optimistic, CalSol software)
-8 months of use.
Solar DHW from May 15 to October 15, boiler off.
Mixed DHW from April 15 to May 15
Mixed heating from March 1 to April 15 and from October 15 but November and December very little sun ...
Before, last 3 years: 2400 L of fuel oil; 2000 kWh of off-peak hours; 2250 kwh of full hours.
As of 15 Dec 1T300 used, i.e. 15kg / day of use. Since it freezes it's more ...
Calculations from 8 months:
Consumption for a year:
650kwh of off-peak hours; 1900 full hours; just under 4T of pellets. Solar 1800 to 2000 to see in spring.
Solar panels with pellets, it's a bit of a luxury because we save on cheap energy ... However I think a CESI with 2 or 3 panels is wise, boiler shutdown in summer so longevity.
Kind regards.

JC

[bernardd]

Hi,

Thank you very much for this very interesting description: not only is it a beautiful installation for you, but it is a real textbook case to show the interest of this solution!

Just a few questions, I can't help it :-)

Balance sheet:
Solar DHW from May 15 to October 15, boiler off.

That's the big interest ...

Mixed DHW from April 15 to May 15
Mixed heating from March 1 to April 15 and from October 15 but November and December very little sun ...

Sorry, I did not understand the difference between mixed DHW and mixed heating?

Have you been able to see what is the limiting factor so that solar DHW is no longer sufficient between April 15 and May 15? Increase the hot water supply, or increase the surface of the panels or both would increase the solar period only?

And would the passage / addition of vacuum collectors gain anything?

Calculations from 8 months:
Consumption for a year:
650kwh of off-peak hours; 1900 full hours; just under 4T of pellets. Solar 1800 to 2000 to see in spring.

Do you know what is the origin of the remaining electrical consumption?

For solar production, is it only thermal? How did you get the production figure?

Solar panels with pellets are a bit of a luxury because we save on cheap energy ...

If I believe your purchase price, the pellets (5KWh / kg) provide an energy of around 4500x5 = 22500KWh for 1050 €, or 4,6c € / KWh, not counting the depreciation of the boiler at € 7809, or € 780 per year over 10 years, which adds € 3,9c / KWh for 4t consumed per year.

But if it also lasts 37 years and the pellet machines are becoming more and more popular for using garden waste, then it becomes really interesting :-)

Solar thermal collectors even at € 400 / m2, for 20m2, cost € 8000, almost the price of the boiler, but without consumption. Is it cheaper to produce 600Wp / m2 (60% efficiency) than pellets?

Would i have made a mistake?

[manet42]

Hi,

- Mixed DHW, that means that the boiler was turning and supplementing the solar if necessary. Heating stopped, just hot water production.
-Mixed heating same thing, finally the boiler heats the top of the tank and the solar bottom in addition.
-Between April 15 and May 15, irregular sun (Lorraine), I did not dare to stop the okofen, although ... the balloon at 85 ° gives 2 days of DHW or even 3 saving (not bathroom!).
-More sensors, it becomes unprofitable because little additional input. When there is no sun ... It does not.
-Vacuum sensors? discussions on others forums, perhaps.
-A better 45 ° tilt = latitude, yes, 10 to 15% better.
-Elec remaining: kitchen, motors of appliances M to L, freezers, fridge etc.
-Measuring solar energy, there is a meter, not too reliable on the Rotex, I also made an estimate based on the savings.
- No errors, except that 600Wp / m2 not sure, Different calculations gave me between 2000 and 5000 kwh for my panels. Only an exact assessment over a year will confirm, distrust of optimistic forecasts.
To note a small problem yesterday, freezing at -6 °, sun AM, sun blocked, a plug of ice certainly in the circuit, I just contact the installer, it should not happen if he has respected The hills.
I estimated the annual savings between 1100 and 1200 euros per year compared to fuel oil and the previous one.
Kind regards.

JC

[bernardd]

Hello,

-Between April 15 and May 15, irregular sun (Lorraine), I did not dare to stop the okofen, although ... the balloon at 85 ° gives 2 days of DHW or even 3 saving (not bathroom!).

Precisely, by increasing the size of the balloon, the reserve would be greater and would allow to hold longer without sun?

-More sensors, it becomes unprofitable because little additional input. When there is no sun ... It does not.

Unless storage has also increased, right?

-Vacuum sensors? discussions on others forums, perhaps.

If they can go up faster in production and at higher temperature, they allow recharging faster, right?

-Elec remaining: kitchen, motors of appliances M to L, freezers, fridge etc.

Not seen a pellet stove yet :-)

On the other hand, I wonder why the fridges and freezers do not store more cold, to charge at a low price ... And in winter an arrival of cold air :-)

- No errors, except that 600Wp / m2 not sure, Different calculations gave me between 2000 and 5000 kwh for my panels.

I wrote Wc for Watt Crete, I do not know the sunshine or the yield to arrive at the energy captured.

To note a small problem yesterday, freezing at -6 °, sun AM, sun blocked, a plug of ice certainly in the circuit, I just contact the installer, it should not happen if he has respected The hills.

Is it a system that drains when the sensor is cold?

Thank you very much for all this concrete information!

[Did67]

To note a small problem yesterday, freezing at -6 °, sun AM, sun blocked, a plug of ice certainly in the circuit, I just contact the installer, it should not happen if he has respected The hills.

JC

I think you have a self-draining system ("drain-back")?

According to a professional (self-employed craftsman) met during an evening, he gave up this system precisely for that: too much problem with the gel ...

[Christophe]

The installation was poorly done Did67 ...a drain back system is more resistant than a pressurized system whether it is frost or overheating ...

But it is also more complex to implement than a pressurized system ... so I understand that a pro does not want to install a drainback ... but it's not because of the frost ... it's is because he doesn't want to get bored ...

Then there is also a lot less manufacturer in drainback ...

[manet42]

Hi,
Yes, we can use a larger balloon, for example 2 Rotex (of which only one solar) of 500L but that increases the price ... Some even make reserves of 2000 or 3000L (site APER SOLAIRE) but there it is a other technique: Hydroaccumulation. The buffer tank is also heated with the boiler, so 3000 or even 7000L ...
Larger surface area of ​​the panels, more storage, yes, but we fall back on the price, it becomes more than unprofitable. Basically, 1m2 per 10m2 heated is the right ratio. There are lots of sites where it is developed.
Plans or empty, opinions diverge ... see the different sites. I chose the plans, a friend almost next to them in a vacuum. It is not the same installation but equivalent surfaces. No big differences.
Yes, it is a self-draining system (Drain-back). They empty themselves if not needed. I didn't want antifreeze.

For Did:
I inspected the pipes ... The pipes go down to the outside. and at the entrance to the wall, there is a slight siphon, they reassembled the tubes at the level of the ceiling inside! In April, no problem with the protection and the chute it resists -2 ° / -5 °. In my opinion it's there ..- 8 ° to -15 ° these days ..
If it were not under warranty I would intervene easily ....

cordially

[bernardd]

Yes, we can use a larger balloon, for example 2 Rotex (one of which is solar only) of 500L but that increases the price ...

When you separate the "hot" side and the "cold" side, you can take standard or even second-hand tanks: the "old" water heaters are more often thrown away for resistance, not for the tank ...

Some even make reserves of 2000 or 3000L (APER SOLAIRE site) but there it is another technique: Hydroaccumulation. The buffer tank is also heated with the boiler, so 3000 or even 7000L ...

If we have several buffers, we can reserve some for solar storage, and only one for combustion heating, because we do not need to store it effectively. But it is necessary to study the circuit well, and possibly play on the valves, which conventional management will not do.

Larger surface area of ​​the panels, more storage, yes, but we fall back on the price, it becomes more than unprofitable. Basically, 1m2 per 10m2 heated is the right ratio.

I understand, but I was not talking about price: I was wondering if the parameter that limits your installation is the surface of the panels or the quantity of hot water stored.

For the ratio, I agree in principle. So the ratio is not absolute, it depends on the price. In particular, if the price of the panel reaches 100 € / m2, then the ratio will be very different, right?

I chose the plans, a friend almost next to them in a vacuum. It is not the same installation but equivalent surfaces. No big differences.

It's a very interesting situation to compare :-)

I didn't want antifreeze.

What is the reason for the desire not to use antifreeze? Otherwise a little salt can help, but perhaps the risk of corrosion on the metals used? I don't know, we put it in swimming pools, but everything is plastic.

Warmly, considering the free snow insulation ;-)

[manet42]

Hello,
Yes, many solutions are possible, an example:

http://www.apper-solaire.org/Pages/Expe ... Drainback/

I remain in awe of these designers / directors, it exceeds my skills, and explains my choice, simpler, more expensive and developed by a professional.
Good research.

JC