DIY questions! - 100+v system to run heating and general appliance in Denmark 10k kwh yearly.

[lykkechristian]

Hello to everybody!

I am Christian from Denmark, currently traveling the pan american highway from USA to Chile!
Since then i have been amazed about relying on the sun driving my Campertruck.


Now i am trying to calculate if possible and what i need to run everything solar at home. Denmark does have long periods of bad cloudy weather.

I want to run following. So here is my minimum requirements.

1. 9kw heatpump (Air to water) - This i have to install, so am unsure about kwh a year consumption. but roughly 6.000 kwh.
2. General appliances (Normally i use 3.000 kwh a year.

I am thinking of installing enough for 10 kwh consumption to be sure.



My thinking is.

Panels:
12kwp panels. (32 panels of 380 watt) . = Estimated 7.000 usd
Denmark gets around 1000 w/m2 and generally 1.000 kwh per 1 kwp panels.
So system should generate around 12.000 kwh hours.

Inverter:
Growatt - (SPH10000TL3 BH) - PV max 13kw, AC output 10kw. (Battery voltage 100-550 volt). = Estimated: 2.000 usd
or
Sungrow - (SH10RT) - PV max 15kw, AC output 10kw. (Battery voltage 150-600 volt). = Estimated: 2,000 usd

Batteries:
Batteries: 4 x 48v 100 ah, Lifepower 4 battery by EG4. = Estimated: 7.000 usd

I would need minimum 4 in series to get above the battery range for the inverters. 48v x 4 = 192 Volts.

Total battery capacity would be: 19,2 kwh at 48v (x4) towards. 20,48 kwh at 51,2v (x4)


Total:
Estimated 16.000 usd.
I am aware that i need cable, meters, mounting racks, fusing etc.



Questions:

1. Does this sound correct or am i missing something and/or something i need to consider?
2. Would it be better to go with smaller inverters (48v) and then have multiple to run more wattage?
3. As i see it i might need much more PV, because of lack of sun in winters (Which is also where most power will be used for heating)
4. I am not sure how to calculate if i would have enough battery, since consumption would be 10.000kwh / 365 = 27 kwh a day.
5. Anybody know i it can be setup to heat only extra during the day with sun (even at 50% sun, would be enough to heat - since the heater also doesnt go all the time, but periodically)


Please come with input etc.
And thanks in advance.

Christian

 

[Bvillebob]

I would just say you probably can't plan based on annual use, given your location in Denmark, you need to think about a week of use in December and January. Here in Oregon I think our climate is pretty similar to Denmark, and you are even further north than us at 45 north. For the last month my 10KW of panels have generated anywhere from 1-10 kWH per day, with an average of about 5 kwH per day. The sun is very low and clouds can stay for a week or more at a time. I currently have 10 KW of panels and will be adding another 10 kw soon, which is much more than I need for half the year but is barely enough in the winter when production is very low.

Something to think about. I envy your trip, I was just in southern Mexico when Covid started, I was traveling in my van for the winter and met many people heaed south for the Pan American. I turned around and headed home before things got too crazy, but I often think about them and how their trips turned out out with all the borders closing. I hope things are better for you now.

 

[Hedges]

Half the price is batteries?
Try to get by with less, and consider DIY. I think 48V 280 Ah can be done for < $2500
A generator to use when there's no sun should make less battery manageable. Try to capture waste heat from it.

Consider 48V battery inverter. You can make a system in the 5kW to 24kW or so range. I use SMA which is expensive, but there are other brands in the $1500 range.

 

[Denver]

Hello to everybody!

I am Christian from Denmark, currently traveling the pan american highway from USA to Chile!
Since then i have been amazed about relying on the sun driving my Campertruck.



Please come with input etc.
And thanks in advance.

Christian

Please to watch out for common bandits and both communist and fascist revolutionaries. what you are doing is not safe.

 

[lykkechristian]

I would just say you probably can't plan based on annual use, given your location in Denmark, you need to think about a week of use in December and January. Here in Oregon I think our climate is pretty similar to Denmark, and you are even further north than us at 45 north. For the last month my 10KW of panels have generated anywhere from 1-10 kWH per day, with an average of about 5 kwH per day. The sun is very low and clouds can stay for a week or more at a time. I currently have 10 KW of panels and will be adding another 10 kw soon, which is much more than I need for half the year but is barely enough in the winter when production is very low.

Something to think about. I envy your trip, I was just in southern Mexico when Covid started, I was traveling in my van for the winter and met many people heaed south for the Pan American. I turned around and headed home before things got too crazy, but I often think about them and how their trips turned out out with all the borders closing. I hope things are better for you now.

Hi Bob!
No, that is the same thinking that i have had. But i will be grid connected so it is okay if i am 80% solar driven
And yes, we have similar climates, but ours is cloudy for even longer... haha.

So i was thinking i want to be ofcourse able to go maybe 2-3 days without sun, and then hopefully the sunny days can top the batteries up.
I wonder if there is a way to calculate this. I think i need minimum double the amount of batteris now. And probably also double solar panels. ince, we will have many days at 0-40% sun, and to capture as much as possible in short time requires more wattage..

Our electric prises this winter have had quite a crazy time. Usually it is stable around 40 usd cent a kwh. this winter because of gas prices going up in europe, we have seen it spinking to 1-2 usd a kwh. So i am feeling the want to be more independent from that.


Well, we were in USA from november 2020 - january 2021. And then we were in Baja for 1-2 months January-march 2021. Since then moved our way down all the way to panam. Due to covid the border crossing in south america was impossible, so we decided to cut out alot of countries and ship it directly to Chile. We are now on the carretera austral
This trip is gonna be 1,5 years, and we are so happy we did it, even though covid Friends at home have been in much more strick lockdowns. And somehow we feel safe on the road because of the very minimum amount of human contact that is needed.
Groceries, a few restaurant visits and otherwise being outside and in nature seems to be very safe

Where are you based ?

 

[lykkechristian]

Half the price is batteries?
Try to get by with less, and consider DIY. I think 48V 280 Ah can be done for < $2500
A generator to use when there's no sun should make less battery manageable. Try to capture waste heat from it.

Consider 48V battery inverter. You can make a system in the 5kW to 24kW or so range. I use SMA which is expensive, but there are other brands in the $1500 range.

Yes, naturally cut consumptions is the best way
We are already pretty low maintenance i think with max 3.000 kwh a year. So i am okay with that.
Generators wont work for us, as fuel s 9 usd a gallon. We have okay decent pricing for electricity. So i will top off batteries from the grid during a cloudy day. And then consume it in the evening (Where prices double).
The watteage from a 48v system is pretty low isnt it? We would need to use 7.000 watt at times as the heatump will heat housing and consumption water.

So the inverters i look at are around 10.000 watt output. These all seem to be 100+ voltage for the batteries.

Do you have any ideas?

 

[lykkechristian]

Please to watch out for common bandits and both communist and fascist revolutionaries. what you are doing is not safe.

Hi Denver,
We have felt safe the whole way. The world is not as bad as portraied on media.
We are now already through north, central and south. Never felt unsafe
Just dont go in bad areas at night, which counts in all countries.

To be honest, we felt the most unsafe in sketchy US neighbourhoods.

Have a nice day!

 

[Hedges]

So the inverters i look at are around 10.000 watt output. These all seem to be 100+ voltage for the batteries.

Do you have any ideas?

The inverters I use are SMA Sunny Island, 48V battery and 6kW per inverter. Up to four of them can be connected in parallel (or split-phase as used in US). Three for 3-phase. So up to 24kW inverting from battery. 110A each charging battery, so up to about 22kW charging.

They can be used with separate DC coupled battery chargers, but I use AC coupled Sunny Boy inverters. Could have 48kW of GT PV inverter, half the power going to charge batteries and half supplying loads during the day.

Batteries can be lead-acid forklift type, or lithium. Some commercial batteries are compatible (talk over a bus to adjust charge rate, etc.) and there are BMS from REC which work for DIY batteries.

A suitable size system for your needs could be made with those.

https://files.sma.de/downloads/SISYSGUIDE-KEN140421.pdf

I'm not familiar with the 100V battery range of products you mention.

There are 400V battery systems as well. Haven't heard of anyone building DIY battery. The smaller units for home use actually have a 48V battery and boost converter inside. Larger commercial system I assume have native 400V battery. SMA has them from 75kW 3-phase up to 4MW.

 

[Hedges]

Generators wont work for us, as fuel s 9 usd a gallon. We have okay decent pricing for electricity.

Grid is usually the most economical, even if fairly high rates.
Battery storage costs more, and generators do too unless fuel is cheap. One guy here figured diesel generator was costing him $0.50/kWh.

Gas generator, even with expensive fuel, can save money for offgrid/backup by letting you have a smaller battery.

Lithium batteries (except DIY and recycled) cost several times what lead-acid do, and last several times longer.
I put commercial lithium batteries and AGM lead-acid at $0.50/kWh. FLA $0.25/kWh. DIY lithium can be $0.05/kWh.

If lead-acid battery is sized for 3 days without sun, it can last 20 years. One guy here recently wrote his Rolls Surette were that old, and had about 40% capacity. In this case, lithium's longer cycle life is something you may never see, so likely not worth the higher price.

Lithium has its advantages and its challenges. If you made a system with just one day (or only one night) storage, then the 3000 to 6000 cycles of lithium could be used. On cloudy days (without grid) you would run out of power. That's where a gas generator, despite its high price for fuel, could save you money on a battery 1/3 or 1/6th as large.

I put PV and GT inverter at $0.025 to $0.05/kWh (amortized over 10 years) assuming free DIY labor to install. Even cheaper over its > 20 year usable life. So that saves money vs. grid, assuming either net metering or sized to offset loads. Can even be oversized, discarding unneeded generation, given the savings over utility rates.

Batteries generally don't save money vs. grid. Except, if "demand charges" for peak use are much higher, in which case value to shave those can be dollars per kWh.

 

[Denver]

Hi Denver,
We have felt safe the whole way. The world is not as bad as portraied on media.
We are now already through north, central and south. Never felt unsafe
Just dont go in bad areas at night, which counts in all countries.

To be honest, we felt the most unsafe in sketchy US neighbourhoods.

Have a nice day!

sketchy US neighborhoods are bad. But go to a sketchy El Paso neighborhood then cross the border to a Ciudad Juarez neighborhood and you'll find a whole new meaning of the word sketchy.

so, you actually drove from north of the Panama Canal to Columbia, via the Darian Gap where there are no roads, and you didn't arrive dead? There's no way to drive from North America to South America nonstop.

 

[ORi0N]

Inverter:
Growatt - (SPH10000TL3 BH) - PV max 13kw, AC output 10kw. (Battery voltage 100-550 volt). = Estimated: 2.000 usd

Batteries:
Batteries: 4 x 48v 100 ah, Lifepower 4 battery by EG4. = Estimated: 7.000 usd
I would need minimum 4 in series to get above the battery range for the inverters. 48v x 4 = 192 Volts.

Why 4? You only need 3 to get above the 100V you listed for the inverter. Also be very very very careful with DC voltages above 50V. Your system is worthless when you're dead, think about it.

I bought the same Growatt inverter and I'm eyeballing some cheap 280Ah 3.2V LiFePO4 on Aliexpress. The idea was to put 36 in series which gives me for the typical 3.0V - 3.2V operating range a total of ~ 108V - 115V which should fall within the 100V+ for the Growatt inverter and makes a totdal storage capacity of 32 kWh.
I have been looking for a BMS with CANBUS option (as the Growatt supports that) to monitor the cells, but couldn't find a 28s+ BMS, so I'll need to split up I guess. Hints and tips are welcome, I've never done more than 10s acually.

 

[lykkechristian]

The inverters I use are SMA Sunny Island, 48V battery and 6kW per inverter. Up to four of them can be connected in parallel (or split-phase as used in US). Three for 3-phase. So up to 24kW inverting from battery. 110A each charging battery, so up to about 22kW charging.

They can be used with separate DC coupled battery chargers, but I use AC coupled Sunny Boy inverters. Could have 48kW of GT PV inverter, half the power going to charge batteries and half supplying loads during the day.

Batteries can be lead-acid forklift type, or lithium. Some commercial batteries are compatible (talk over a bus to adjust charge rate, etc.) and there are BMS from REC which work for DIY batteries.

A suitable size system for your needs could be made with those.

https://files.sma.de/downloads/SISYSGUIDE-KEN140421.pdf

I'm not familiar with the 100V battery range of products you mention.

There are 400V battery systems as well. Haven't heard of anyone building DIY battery. The smaller units for home use actually have a 48V battery and boost converter inside. Larger commercial system I assume have native 400V battery. SMA has them from 75kW 3-phase up to 4MW.

It makes me think for sure.

My problem is also with the BMS, being able to handle the amount of draw as i would also like to size everything so that i would be able to charge and electric/hybrid car in the future.


I think i will have to find a proffesional for some consulting as the system ends up being quite massive.
We do not want gas/diesel/propane generators as those fossil fuels are way to expensive where we live. It would be better just to tap on the grid when needed. But we are having problems as Electricity prices are becoming ridicoulous at up to 2 usd per kwh in peak times between 17-20. This is why i would prefer to become 90% fully off grid.
I appreciate your insight!

 

[lykkechristian]

Grid is usually the most economical, even if fairly high rates.
Battery storage costs more, and generators do too unless fuel is cheap. One guy here figured diesel generator was costing him $0.50/kWh.

Gas generator, even with expensive fuel, can save money for offgrid/backup by letting you have a smaller battery.

Lithium batteries (except DIY and recycled) cost several times what lead-acid do, and last several times longer.
I put commercial lithium batteries and AGM lead-acid at $0.50/kWh. FLA $0.25/kWh. DIY lithium can be $0.05/kWh.

If lead-acid battery is sized for 3 days without sun, it can last 20 years. One guy here recently wrote his Rolls Surette were that old, and had about 40% capacity. In this case, lithium's longer cycle life is something you may never see, so likely not worth the higher price.

Lithium has its advantages and its challenges. If you made a system with just one day (or only one night) storage, then the 3000 to 6000 cycles of lithium could be used. On cloudy days (without grid) you would run out of power. That's where a gas generator, despite its high price for fuel, could save you money on a battery 1/3 or 1/6th as large.

I put PV and GT inverter at $0.025 to $0.05/kWh (amortized over 10 years) assuming free DIY labor to install. Even cheaper over its > 20 year usable life. So that saves money vs. grid, assuming either net metering or sized to offset loads. Can even be oversized, discarding unneeded generation, given the savings over utility rates.

Batteries generally don't save money vs. grid. Except, if "demand charges" for peak use are much higher, in which case value to shave those can be dollars per kWh.

Yeah, as i mentioned above. No generators for us, even though you are correct. Fairly high rates in the US is nothing near what we are seeing atm.. And as the government pushees us towards electric cars for a greener future. It will only become more expensive as they will need the taxes that they loose on fossil fuels anyways. I expect electricity prices to become much higher as well. As i said, this is why i am prepared to sepnd a good chunk of money on becoming as self sufficient as possible within reason Thanks for your thougts!

 

[lykkechristian]

sketchy US neighborhoods are bad. But go to a sketchy El Paso neighborhood then cross the border to a Ciudad Juarez neighborhood and you'll find a whole new meaning of the word sketchy.

so, you actually drove from north of the Panama Canal to Columbia, via the Darian Gap where there are no roads, and you didn't arrive dead? There's no way to drive from North America to South America nonstop.

Ofcourse, but that is why i told you. That we use our common sense in all regards and probably why we have never felt unsafe
No we shipped our car over the darien gap. But it is actually something you can drive. but it is really complicated. So yes it is driveable.
But yes we went from USA, mexico, guatemala, honduras, nicaragua, costa rica, panama, then truck camper shipped with roro to Chile, as we the borders between the northern countries of south america where closed, we decided to go to chile. We are now in argentina, and have 1 month left of our 1,5 year journey. Then a new adventure awaits

 

[upnorthandpersonal]

I would need minimum 4 in series to get above the battery range for the inverters. 48v x 4 = 192 Volts.

I don't think you can put EG4 batteries in series. Someone prove me wrong.

 

[lykkechristian]

Why 4? You only need 3 to get above the 100V you listed for the inverter. Also be very very very careful with DC voltages above 50V. Your system is worthless when you're dead, think about it.

I bought the same Growatt inverter and I'm eyeballing some cheap 280Ah 3.2V LiFePO4 on Aliexpress. The idea was to put 36 in series which gives me for the typical 3.0V - 3.2V operating range a total of ~ 108V - 115V which should fall within the 100V+ for the Growatt inverter and makes a totdal storage capacity of 32 kWh.
I have been looking for a BMS with CANBUS option (as the Growatt supports that) to monitor the cells, but couldn't find a 28s+ BMS, so I'll need to split up I guess. Hints and tips are welcome, I've never done more than 10s acually.

Sorry for the late reply!

I would need 4 if i went with my second option as it requires voltage above 150 volt.
Yes i definitely will need a good electrician in the mounting phase to make sure everything is good.
I saw those one aliexpress and have been wanting to buy them as well. I also hit a wall when it came to the BMS. did you find a solution?
What was the cost of those 32 kwh ? You might look into if it is worth it compared to also having to buy BMS etc compared to EG4 systems that at the moment are coming out quite cheap to be honest


Look forwards to hearing about your project. Where are you located etc? Whats your plan?

 

[lykkechristian]

I don't think you can put EG4 batteries in series. Someone prove me wrong.

Why would you not? I see them in server racks on youtube quite often

 

[upnorthandpersonal]

Why would you not? I see them in server racks on youtube quite often

Yes, in parallel.

 

[timselectric]

You would have to check the battery specs to see how many you can put in series. Could only be rated for 2 in series. They are usually used in parallel for 48v systems.

 

[upnorthandpersonal]

You would have to check the battery specs to see how many you can put in series. Could only be rated for 2 in series. They are usually used in parallel for 48v systems.

As far as I remember, the spec sheet doesn't mention anything about series operation, only parallel. Considering their original use case (telecoms) I don't believe these are able to be used in series to create higher voltage packs, especially 4 or so - the BMS would have to have been massively overrated for this to work and you'd expect the manual to mention this.