Hello from Paris (sticks of), France

Fluffy78

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Apr 12, 2021
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Hello everyone,

My name is Cédric, I live in the suburbs of Paris, France (aka the sticks). So about ten years ago I bought this plot of land and, with my wife, we built a house on it (no kits, just DIY home building, we did everything on it).

At the start of the construction I had decided to put solar panels on the roof at some point in time (when I had the money & courage to do so). We decided to build a 100% electrical house, no gas, no wood, so as to later exploit the PV system to it's fullest.

From an insulation standpoint, to make it live-able (heating, lighting, ...), it consumes around 37kWh/m2/year, the entire electrical bill (with an EV car) is at 60kWh/m2/year - prior to the installation of PV panels.

I put a south roof at 35°, beyond I didn't see myself climbing on it actually, made it ready for PV (ie attachments etc).

So, fast forward several years, I've put, for now, 12 panels @ 365Wp with associated enphase micro-converters and it's running fine. I put load sharing systems coupled to an astro controller to heat water in the day (for example). I put micro-converters because I have very old oak trees in the garden that cast some shade over the roof during the day and there was no way in hell that I was going to cut those trees down. They do get trimmed to stay in shape by a pro every two years but it's only trimming of dead wood; they're too high for my taste ... I'm not suicidal, getting on a roof is one thing, going to the top of 30 meter oak tree is another, it's a long fall ...

I'm now getting ready to add batteries to the system (and add solar panels to go with) but, given that my core driver was to reduce my carbon footprint, I don't want to buy new batteries, rather I want recycle older batteries no longer fit for purpose (for example a Tesla battery from scrap yard).

So I've come here to benefit from your collective experience to figure out a way to solve my issue of getting a HESS based on second life batteries whilst remaining compliant to french electrical regulations.

Thank you for welcoming me amongst you,

Cedric

ps: For those who are wondering, Fluffy is a nickname that my US Corvette friends have given me a while back and it stuck. Yes, I do have a Corvette, as such I my carbon neutral objective is going to be more challenging to meet :LOL:
 

floydR

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hello Cédric welcome to the wonerful world of recycling batteries many have gone to new large format LiFePO4 cells so there is a chance that used18650's will become cheaper to obtain for Second life usage. Ev batteries are great for second life uses. many folks here use leaf, tesla, etc batteries for there Second life power wall.

Later floyd
 

italianuser

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Feb 25, 2020
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Hi there Cédric "Fluffy" from the Sticks! :giggle:and welcome to You!
Love your french humour... so "fluffy" is because of your... hair? LOL

This week is crucial for me... I chose the hybrid inverter, the panels and the batteries, only waiting for the engineer's point of view for the papers to be presented at the counsil... and must buy the cables!

jes
 

Fluffy78

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Apr 12, 2021
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Hi there Cédric "Fluffy" from the Sticks! :giggle:and welcome to You!
Love your french humour... so "fluffy" is because of your... hair? LOL
Thank you!

It's a long story ... but a picture is better than a 1000 words they say (it's my car)
 

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OffGridInTheCity

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I'm in Southern Oregon USA (Pacific Northwest) and we embarked to make our house in the middle of the city as 100% off-grid capable. So I share your enthusiasm to be 100% electrical etc. For example, we converted to heat-pump hot water heater and converted to a whole house heat pump a year ago. Don't have electric car yet - but its coming at us all :)

I was curious when you say "....60kWh/m2/year..." What does the "m2" part of this mean?

In any case, welcome to the forum and you can get good info on DIY battery bank sizing/building/operating here for sure :)
 

Fluffy78

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Hello,

In France, given that we don't all have the same homes (surface wise), we compare the energy efficiency of every home by bringing the required electrical power to an index which is computed over a year per square meter of living space (garage is excluded as it isn't livable). It's a required index if you want to rent or sell the home (and you get tax breaks if your house is good).

So, my house, requires, 37kWh per year per square meter to have it heated/cooled (basically A/C), hot water (for showers, etc), lighting (so you can see in the dark). An energy efficient home has to be below 50kWh per year per square meter (it depends which part of France, my area is actually 65kWh/m2/year because it is colder in winter).

If you have a wood stove/heater, than there is a conversion rule in relation to the quantity of wood you burn, which I can't provide because my home is 100% electric, so I'm not familiar with the maths.

In addition to this there is a secondary index which is the total amount of energy the house uses (you would include the flatscreen in the second index and not the first). As my wife is a homemaker (she makes her own bread daily), the kitchen is my number #1 power hog (extremely surprised in electrical consumption between two fridges of different quality), second power hog is the E/V and this consumption goes to the secondary index.

So the secondary index for my home is 60kWh per livable square meter per year which is actually lower than the required standard for the first index.

These indexes are compounded by the number of persons in a home. So the number 50kWh/m2/year (65 in my region) is for a family of 4. In my case, I have triplets, so we're 5 in the household. I know we are allowed to have more (kids taking hot showers) but I'm not familiar with the offset maths.

Now given that my home produces it's own energy via PV my actual power requirement has gone down. Technically you can deduce the energy produced by your PV from your first index, but if you ask me it's rip-off.

The reason being that if my home is an energy hog, I can put 50 PV panels on the roof and theoretically have an energy efficient home. For me, it's hogwash, the home is still an energy hog, no matter how you spin it.

So I stick to my index without including the offset that my solar panels bring to the home, nor do I offset the additional power requirements of the fifth person in the home.

Hope this clarifies, sorry for the long answer,

Cédric

ps: Getting pretty familiar with the USA now. When I was dating my wife she said her husband had to make her visit all the states of the US. Been going to the US for a month hiking/camping almost ever year since we got married in '03 ... have yet to go to Mount Hood though.

pps: Homes are also ranked from an acoustical efficiency/isolation and a bunch of other stuff.
 
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OffGridInTheCity

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Fantastic, thanks you for this info / perspective.

Last year my home consumed 33,249kwh. 15,013kwh net came from my 13kw array (45 panels) and 18,236kwh came from the grid. At base size of 242m2 that gives me 33,249kwh/242m2 = 138kwh/m2/year. However, in an emergency we can cut out several big power items and have a perfectly livable home spring/summer/fall. For winter, we have an extra 45 panels stored under the house that can be deployed to bring things up to enough power to be livable.

So while we weren't able to achieve 100% PV for our regular lifestyle we have done a reasonable job so we could live OK if a Puerto Rico style evet occurred where we lost grid for a few months. Who knows, maybe my wife will let me put up 45 more panels one of these days :)
 

ajw22

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Welcome to the forum!

[...] if you ask me it's rip-off. The reason being that if my home is an energy hog, I can put 50 PV panels on the roof and theoretically have an energy efficient home. For me, it's hogwash, the home is still an energy hog, no matter how you spin it.
Have to disagree with this. What matters is reducing the total amount of energy the property uses, and there are many ways to do it. It doesn't matter if it's achieved via passive consumption reduction tech (eg. insulation), active reduction tech (eg. heat pumps), or offset with clean energy generation tech.
Neither global CO2 output, nor the homeowners pocket$ will care if offsetting via PV seems like cheating. If you have the space and money, add even more PV and offset your property into the negative and feel good about it!
The only one who won't be happy is your local energy provider, and government with less sales/fuel tax income - that's confirmation you're doing good!
 
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italianuser

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Fantastic, thanks you for this info / perspective.

Last year my home consumed 33,249kwh. 15,013kwh net came from my 13kw array (45 panels) and 18,236kwh came from the grid. At base size of 242m2 that gives me 33,249kwh/242m2 = 138kwh/m2/year. However, in an emergency we can cut out several big power items and have a perfectly livable home spring/summer/fall. For winter, we have an extra 45 panels stored under the house that can be deployed to bring things up to enough power to be livable.
...
Oh my... that's big numbers. I consume around 245KWh/month, that's about 3,000KWh/year for 140 square meter flat, plus 1,500€ (1,800$) methane gas/year.
 

Fluffy78

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Oh my... that's big numbers. I consume around 245KWh/month, that's about 3,000KWh/year for 140 square meter flat, plus 1,500€ (1,800$) methane gas/year.
Depending on the type of your gaz, one cubic meter provides between 9kWh up to 12kWh. So you can bring it all back into kWh per annum
 

Fluffy78

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Welcome to the forum!


Have to disagree with this. What matters is reducing the total amount of energy the property uses, and there are many ways to do it. It doesn't matter if it's achieved via passive consumption reduction tech (eg. insulation), active reduction tech (eg. heat pumps), or offset with clean energy generation tech.
Neither global CO2 output, nor the homeowners pocket$ will care if offsetting via PV seems like cheating. If you have the space and money, add even more PV and offset your property into the negative and feel good about it!
The only one who won't be happy is your local energy provider, and government with less sales/fuel tax income - that's confirmation you're doing good!

From an ecological perspective, I dissent slightly. My point is that if you have a none insulated house you will burn a lot of energy to heat it. That energy in turn is increasing our footprint (you're heating the atmosphere).

Whereas if you have an insulated house, you will burn less energy and therefore you're environmental impact is less.

Take a fridge, is it better to have an insulated fridge wherein the door is kept closed whenever possible, versus having 20 solar panels on the roof and an open door fridge?

My perspective, is that having an insulated house is better for the environment, having an insulated house that is self sustaining is even better.
 

ajw22

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From an ecological perspective, I dissent slightly. My point is that if you have a none insulated house you will burn a lot of energy to heat it. That energy in turn is increasing our footprint (you're heating the atmosphere).

Whereas if you have an insulated house, you will burn less energy and therefore you're environmental impact is less.
If that extra heat "burned" comes entirely from your PV panels... those captured solar rays would otherwise just heated up your roof tiles and thus the atmosphere either way, no? Albedo and production/recycling comes into play, but emissions wise, having PVs that generate 1000kWh/year is pretty similar to adding insulation that reduces energy usage by 1000kWh/year.
You should do both as much as feasible, and proudly get credit for both... then reinvest those credits/savings in even more PV to cover the consumption of your neighbors!

One consideration why PV might be better in your case: you mentioned spending 1 month every year in the US. PVs keep producing clean energy even when you're gone. Whereas energy reduction measures do zip when you're away and not heating/cooling the house.

Take a fridge, is it better to have an insulated fridge wherein the door is kept closed whenever possible, versus having 20 solar panels on the roof and an open door fridge?
So closed efficient fridge, but powered by dirty generator (disregarding France has lots of nukes), vs
open inefficient fridge, but powered entirely by solar panels. It's a toss-up, with plenty of PROs and CONs on both sides.
 

OffGridInTheCity

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Oh my... that's big numbers. I consume around 245KWh/month, that's about 3,000KWh/year for 140 square meter flat, plus 1,500€ (1,800$) methane gas/year.
Our excessive power consumption is 10,000kwh/year (1/3 of the total) ) because of 3 big things..... 1) a computer server farm (a hobby from work), 2) a spa, and 3) inefficient cooling under the house. These consumption points can be turned off in an emergency - leaving us an 8,000kwh/year gap which we can pretty much fill in with the 45 panel 'emergency generator'.

Its interesting how excessive power consumption occurs. #3 above is due to an under the house access permit in the 'storage class'. Which does not allow making it a livable space (to close off the outside air vents for example) unless we do full HVAC, wall-board, etc. But in the summer it hangs at 85F/30C so we burn power to cool it down to 75F/24C for comfort. We have the computer server farm, exercise area, powerwall/solar area, rain-harvest pump house, and a workshop - so 75F is good for several reasons but its a dreadfully inefficient 'waste' of power .
 
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Fluffy78

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Let's not fight over this, we're all like minded people doing the same thing in different ways 😘

The reason for which in France we measure house consumption over heating (A/C + hot water) & lighting is that it sets aside the extra stuff that people may have such as servers or other things (hence the Tier 1 mesure) and puts a comparable element to set a common goal.
 

italianuser

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@OffGridInTheCity ah that makes sense... A server farm :love:I used to keep it at my shop, then I moved to to french provider OVH, where @Fluffy78 is, because of high electricity bills!
[ They were IBM eSeries, loved them ]
 

italianuser

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ehm yes they did burn:eek:SBG1 datacenter...at 3AM I was just going to bed and saw a red LED flashing... checked services and were all offline, I thought it was a temporary problem. I woke up at 7.40AM and read the news...🤪"SBG datacenter on fire, over 10.000 servers burnt in fire" (yes, I did think of lithium batteries going on fire!).
I had all my services running for customers on six Virtual Machines on a 48GB ESXi host: Windows hosting, Linux hosting, Postgresql database, Mailing List service, Mail service (200 mailboxes, the most critical) and a Munin monitoring VM.
My scheduled backup plans on RBX datacenter saved me from disaster... In 24 hours I had all critical services running again🙌
Now I'm still in the process of rebuilding secondary machines, hopefully next week I'll have all services configured properly, for now I have backups working.
P.S.
Octave Klaba (OVH's CEO) did a great communication job via Twitter, he's still doing it today, with hourly updates on progress. No other company does that and that's the reason I'll stay with OVH. Long story made short! LOL

EDIT: After a few days did anybody notice EEVBlog was offline? They had big problems with their datacenter and stayed offline quite a few days (or weeks?!)
 
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