Asking for advice, heating system replacement

E

elnaib

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May 10, 2020
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Hi,

As I explained in my presentation I would like to replace my fuel-oil calefaction system for a battery calefaction system. Please be patience with me I'm a newbbie and an ignorant. Well the evil plan is to built several power walls in order to feed the system, I have 120m2 to heat in da house. I was thinking about a 14s100p system,51.8v, 260Ah (13.5 kW/h probably this calculation is wrong). Thebatteries will be charged from the grid in the cheapest period, in the future from a pure solar system. The use of the calefaction is around 10-12h/d in winter time. I've saw thatthe consumption of theelectric system is 9 kW/h, itmeans that I would need at least 10 x 14s100p to feed the beast for one day. For clarifications, I cannot connect the electrical calefaction system directly to the grid because all house electrical system would have to be changed, my system only supports 3.3kW/h, so the scheme would be batteries connected to the grid for charge and connected in an isolated system to the electrical calefaction.

All help is welcome

Thanks guys
 
I would use the battery power to supplement the fuel/oil heating of your house using most of the battery for lighting, cooking, laundry,computers with limited heating with a mini split system if the climate isn't too cold.
later floyd
 
elnaib said:
Hi,

As I explained in my presentation I would like to replace my fuel-oil calefaction system for a battery calefaction system. Please be patience with me I'm a newbbie and an ignorant. Well the evil plan is to built several power walls in order to feed the system, I have 120m2 to heat in da house. I was thinking about a 14s100p system,51.8v, 260Ah (13.5 kW/h probably this calculation is wrong). Thebatteries will be charged from the grid in the cheapest period, in the future from a pure solar system. The use of the calefaction is around 10-12h/d in winter time. I've saw thatthe consumption of theelectric system is 9 kW/h, itmeans that I would need at least 10 x 14s100p to feed the beast for one day. For clarifications, I cannot connect the electrical calefaction system directly to the grid because all house electrical system would have to be changed, my system only supports 3.3kW/h, so the scheme would be batteries connected to the grid for charge and connected in an isolated system to the electrical calefaction.

All help is welcome

Thanks guys
Click to expand...
>14s100p system,51.8v, 260Ah (13.5 kW/h probably this calculation is wrong).
You're exactly right. My own system is 14s100p / 260ah@48v nominal - but I also use 52v for my calcs.

A10 x 260ah@52v battery bank is around 135kwh. A consumption of9kwh * 12h = 108kwh. This is 108/135 = 80% DOD / day. 80% DOD is pretty 'hefty' for a pure 'discharge over 12h each day'and I'd (gently) suggest thinking more in terms of 60% DOD goal to greatly extend the battery bank life. 12 x would be 70%'ish DOD, 14 x would be 60%'ish DOD.

However, its not clear (to me from above) whether charge would overlap with discharge - so you wouldn't need an 80% DOD as during the overlap period - the power can go directly to consumption.

Finally - charging 108kwh/day is a pretty hefty amount of current. In a 12hr period that's 9,000w/hour = 240v@38a'ish AC/hr and 52v@173a'ish DC/hr. My own system can do 52v@240a max from a 12.8kw PV array for 80kwh/day max- so you'd need something like 17kw PV array in summer time to produce 105kwh for a day. Maybe 60'ish panels.:)
 
OffGridInTheCity said:
elnaib said:
Hi,

As I explained in my presentation I would like to replace my fuel-oil calefaction system for a battery calefaction system. Please be patience with me I'm a newbbie and an ignorant. Well the evil plan is to built several power walls in order to feed the system, I have 120m2 to heat in da house. I was thinking about a 14s100p system,51.8v, 260Ah (13.5 kW/h probably this calculation is wrong). Thebatteries will be charged from the grid in the cheapest period, in the future from a pure solar system. The use of the calefaction is around 10-12h/d in winter time. I've saw thatthe consumption of theelectric system is 9 kW/h, itmeans that I would need at least 10 x 14s100p to feed the beast for one day. For clarifications, I cannot connect the electrical calefaction system directly to the grid because all house electrical system would have to be changed, my system only supports 3.3kW/h, so the scheme would be batteries connected to the grid for charge and connected in an isolated system to the electrical calefaction.

All help is welcome

Thanks guys
Click to expand...
>14s100p system,51.8v, 260Ah (13.5 kW/h probably this calculation is wrong).
You're exactly right. My own system is 14s100p / 260ah@48v nominal - but I also use 52v for my calcs.

A10 x 260ah@52v battery bank is around 135kwh. A consumption of9kwh * 12h = 108kwh. This is 108/135 = 80% DOD / day. 80% DOD is pretty 'hefty' for a pure 'discharge over 12h each day'and I'd (gently) suggest thinking more in terms of 60% DOD goal to greatly extend the battery bank life. 12 x would be 70%'ish DOD, 14 x would be 60%'ish DOD.

However, its not clear (to me from above) whether charge would overlap with discharge - so you wouldn't need an 80% DOD as during the overlap period - the power can go directly to consumption.

Finally - charging 108kwh/day is a pretty hefty amount of current. In a 12hr period that's 9,000w/hour = 240v@38a'ish AC/hr and 52v@173a'ish DC/hr. My own system can do 52v@240a max from a 12.8kw PV array for 80kwh/day max- so you'd need something like 17kw PV array in summer time to produce 105kwh for a day. Maybe 60'ish panels.:)
Click to expand...
Hi,

Thank you both for replies.

Floyd I will consider your proposal, but the key here is to replace the calefaction since it is to expensive and contaminant.

OffGridInTheCity, thank you for your calulations but according to my own calculations you would need 9/10 kW/honly for feed the calefaction, so as example 400 W/h per panel, you would need 25 panels. Furthermore, in my country there is a rectriction for consumers solar intallations, the max is 10 kW/h, for more potency the installation is considered as industrial and cannot be instalated in a house.

Regarding the connection directly to the comsuption, at this moment is not possible since my electric instalation only support 3.3 kW/h and I cannot change now, because is more expensive, since in my country you paid taxes depending onthe capacity of your instalation. So for this reason is to create an isolate system only to connect calefaction to bateries and bateries connected to grid for charging and to calefaction to feed.


Saludos
 
Problem is that those 3.3Kw input you got does not cover what you need over 24hours so you still need to add something extra on top like solar or what not.

Perhaps change the heater system instead to something more efficient? Pushing out that many kWh into heat is ALOT! I use roughly 100kWh of heating during winter where i live and it would be impossible to go directly to electricity. In my case if i switch i would go towards
1. High efficient system that have an efficiency on atleast 5:1. Where you put in 1 part and get 5 part heat out...
2. Isolate the house.


Both above is what i would start with.
Note that cycling a battery like you intend will kill it in a year or 2. Also note that you have alof of innefficiencys converting. Like going grid -> battery -> heater you loose 15% easy. So that adds up even more. Then calculate the ROI :)

What is "calefaction" ? Heating? What type of heating? Electrical elements?
 
daromer said:
What is "calefaction" ? Heating? What type of heating? Electrical elements?
Click to expand...

Yeah, I had to look it up as well. It's heating. I'm guessing it was a translation issue. Just chose the wrong word. And since he's using fuel-oil, I would assume it's a lot like a gas heater or boiler type setup.

Personally, I would recommend trying to do bulk heating using Solar and if in a good area Wind. Solar is not just electrical panels, but also thermal collectors as well. It's amazing how much heat can be collected inside of a big box painted black inside and has a clear front facing the sun. Even in the far north. I've seen people from the Switzerland heating their homes with these in the dead of winter w/o much issues.
 
Hi,

Thanks for the suggestions, it is obvious that I'm not an English native, and my English is not so good, sorry for that.
Yes, calefaction is heating, thanks to correct me.
My heating system is feeding by diesel (fuel-oil) that boils the water.

Daromer, could you tell me about your heating system?
Korishan, I will read about black boxes.

Saludos
 
>....so as example 400 W/h per panel, you would need 25 panels.
True on paper but you're not going to get100% from a PV array and 400w panels seem a bit 'large' to me for a good price point. I'm operating an arrayof 45 panels @ 285w/panel (from ebay sales)and sharing that they generate 80kwh/day in Southern OR.

>Regarding the connection directly to the comsuption, at this moment is not possible since my electric instalation only support 3.3 kW/h
What I ment was that if you have 3.3kw/h charging the batteries at the same time you are drawing (discharging) 9kw/h, then you have a 5.7kw/h discharge 'net'. So the DOD could be more about 5.7kw/h discharge rather than 9kw/h discharge. It wasn't clear to me how much of the 3.3 kw/h could be used to charge - maybe at night when you don't need the power for living during the day. This 'overlap' (and % of 3.3kw/h)of power going into the battery bank and power coming outwould significantlyaffect DOD / size of battery you need.

**You don't say how much sq ft you need to heat/cool or your climate characteristics.... but heat pump technology would likely help reduce your power needs. I live in a moderate climate and installed a 4 ton whole house heat pump in March So far energy usage is amazingly low - a real game changer.
 
I heat My house with Wood as primary. It cost me 500usd per year in Wood and perhaps 5 days to prepare the Wood


In electricity this would have been 8000usd atleast!!!

I would need insylation to get it better but thats a massive cost and as Long as i feel to work with Wood its cheaper. In Summer i heat house with excess solar energy instead the days its needed.

You can check My YouTube.

Your last Choice is to purely heat with electric elements. Its just not worth it. Its better to use solar air heaters IF so. They are like 80% efficient comparing to solar electricity that are. 15-20%
 
Here's a google image search of what I'm referring to: passive solar heating panel air box

There are different types of these boxes.
- a passive heat box that air just blows through
- a fluid heating unit that then has the fluid pumped to a heat exchanger, like a radiator.
* this one has several designs as well. One of them uses vacuum tubes (this one gets "really" hot). Others use coils of copper
 
There are so many variables it get's specific to your climate and home.

We havemild climate and super efficient heat pump installed in March, and so farApril was only 299kwh to heat the whole (2600sq ft)house for the whole month! At .11c/kwh that's $33. May was 80% heat and 20% AC and came in at 382kwh - $42.

Winters 99%30F low and 55F hi range.Very mild and so I don't know yet but hoping to see the heat pump come in at < $100/month for Dec/Jan/Feb - maybe 35kwh/day. I'm able to generate 400kwh/month in winter so with my backup plan (an extra 30-40 panels stored away) we could actually heat the house enough to be livablein the winter if we had to - maybe go to 65F hi instead of 75F or heat just a few hrs / day.

We had a 'fire place guy' out to see if we could install one - but due to various factors the estimate was$5k+ and that didn't include the brick/wall work - and the guy kept shaking his head and mumbling (no, not good, ...)- so we punted.

I watched a lot of youtubes onwood -> electricity like gassifiers,heat engine, and steam engine but you can't buy themand it takes a lot ofwood/monitoring/noiseto run such a thing for 8hrs/day for many days. A big propane tank (1000gal) and generator would last a long time with littlemaintenance - but wife said NO WAY - and permits might be trouble 'in town'. So... why not just store 40 panels? and if there were a true Puerto Rico emergency, I could drag them out into the back yard (I have room) and just wire them into the existing infrastructure. Meanwhile, the panels and wire can just sit under the house and should work OK 20yrs from now. Don't have to worry about fuel, or wood, or generator etc:)
 
OffGridInTheCity said:
We had a 'fire place guy' out to see if we could install one - but due to various factors the estimate was$5k+ and that didn't include the brick/wall work - and the guy kept shaking his head and mumbling (no, not good, ...)- so we punted.
Click to expand...

You don't want a fireplace. It's very inefficient due to the fact that it's a open chimney and all it does is suck more air out of the house than actually heating it. It's more efficient to have a fire stove. It can double duty as a popcorn popper and it's easier to install.


image_jzmqyk.jpg
 
Hi guys,

Ufff a lot of messages to reply, well I will star replying to OffGridInTheCity.

As I posted in the first message, my house is around 120 m2, divided in 3 floors, the first is the garage and the entrace, so not heating here, the 2nd and 3rd floor togheter have 120m2, the house is not insulated and the windows are old wood windows, more than 35 years old, also with old blinds, in every rooms there is an iron radiator below the window. The orientation of the house is almost N-S.
The climate is a continetal, cold winters and hot and dry summers, the T in winter could be around -10C during the night and 0-10 during the day.
And I would try to charge the batteries during the cheapest period of the grid, around 14-15h, it is clear that with 3.3 kW/h I would charge theoretically 49.5 kW that means 5h at 9.5 kW/h so impossible to maintaint the system.
About the fire place I would like one of them, but not possible I have 5 pets at house.

Daromer

I've saw a lot of your videos overall related to power walls, I am subscribed to your channel when I started to looking for information, I'm wondering if you still mount yours power walls at Jehu Garca style, without BMS! jejejeje sorry a litle joke.
Regarding you wood system is very cheap, in my country there is new systems based on wood pellets, I usually use 2000 L/per year of diesel, this is around 1800-1000 per year depending on the market, and also my system provides me hot water for the house.
With respect to solar heaters I will looking for information.

Korishan
I will search information about your mentioned systems.

Thank you so much for your replies guys
 
No i dont run without bms and never had. I never promotes that.
 
elnaib said:
As I posted in the first message, my house is around 120 m2, divided in 3 floors, the first is the garage and the entrace, so not heating here, the 2nd and 3rd floor togheter have 120m2, the house is not insulated and the windows are old wood windows, more than 35 years old, also with old blinds, in every rooms there is an iron radiator below the window. The orientation of the house is almost N-S.
The climate is a continetal, cold winters and hot and dry summers, the T in winter could be around -10C during the night and 0-10 during the day.
And I would try to charge the batteries during the cheapest period of the grid, around 14-15h, it is clear that with 3.3 kW/h I would charge theoretically 49.5 kW that means 5h at 9.5 kW/h so impossible to maintaint the system.
About the fire place I would like one of them, but not possible I have 5 pets at house.
Click to expand...

Insulate first. 120m2 is roughly 1200sqft. Thats a small area for such a high energy usage. 35 years old windows, is the house older? If not that means it's built in the 80s. By then they should have some insulation in the wall. This isn't like a 1800s Victorian-era house, that I can understand is a energy sucking house. We had this question just recently, and it's probably better to go through an energy audit before going down the renewables route. It's better to make things more efficient than to try getting the cheapest energy. Replacing with double glazed windows, extra insulation at the attic. The plus side is less energy means saving more of the environment as well as money! Getting 100kwh of batteries is also quite costly unless you can get it for free. Pets love fireplaces btw.
 
not2bme said:
Insulate first.
Click to expand...

Second that. Insulation will be much more cost effective and greener than any battery system. Here are some of the easy DIY ones that I personally use:

* Window insulation film. Super cheap, quite effective at stopping the cold.Might not stick well to wood frames. Slightly hazy.Might not last long withpets, depending on species.
https://www.amazon.com/dp/B000NHY1P0

* Plastic double window. I used 4mm thick acrylic for ~$50, a drawer knob, and some pieces of wood nailed to the frame. Excellent insulation, nearly invisible, pet friendly, easily removable.

image_kzuauf.jpgimage_lejkjo.jpg


* Carpets. The thicker and fluffier the better.

* Circulator fans. Get big ones and run on slowest(quietest) setting 24/7. Place on the floor and point it upwards - it'll suck the cold air near the floor and mix it with the hot air near the ceiling, making the room feel _much_ warmer. By several degrees. The fans need some energy, but lowering the thermostat saves you significantly more energy.
https://www.amazon.com/dp/B07BZQKC5M

* Get used to wearing thick socks and fluffy slippers.

* Stop air drafts. Go around the house with a smoke generator (eg. incense), and fill in every gap that lets in cold air / leaks out warm air. Lots of products available for all sorts of leaks. Might want to leave some air flow, depending on the smell ofyour pets. Or look into "heat recovery ventilators", but that's going to cost a fair bit more.
https://www.amazon.com/dp/B01NCNXLA3
https://www.amazon.com/dp/B07DDD6N3R



Finally, the first step before going battery:
* Air conditioner (aka mini splits, air sourceheat pump, etc). Ituses[size=small]approximately[/size]1kWh of energy to pump 3kWh of heat into the house, so much more efficient than other types of electrical heating.Unless you're living in coal country, it'll probably be cleaner than burning oil. Get a smallerunit to assist heating, so that you can switch it to solar/battery power in the future. Will probably not work well at -10C.
https://www.amazon.com/dp/B07DYDG3VP
 
An alternative is a mini split A/C heat pump unit.
I have 2, one in the living room and one in the bedroom. 1.4 Kw of panels feeding into 8 x 6 volt golf cart batteries wired series/parallel to give 24 volts and a usable 4Kw of storage.
We run each one separately. living room in the day bedroom at night, and have never dropped the batteries below 50% DOC.
As a heat pump it consumes 1Kw and as an A/C 900 watts. I put a Killawatt meter on the A/C when it was 114F (45C) outside, and it only used 2.5 Kw total for the day.
Before you do anything, as others have advised, check and improve the house insulation. :)
 
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