HELP : New Hybrid System Design

[greeksolar]

Hello,

I have a farm and large property in Northern Greece. At the moment we have 3 phase grid power, and a 50 KVA generator on a transfer switch, which gets used a lot since the grid is very unstable in our particular area.

I am in the process of specifying a system and was hoping for some suggestions and advice since you folks have experience, and its better to get the right stuff now rather than fix the wrong install later.


20 KW in panels, 550W mono panels, Mounted on a flat roof with NO SHADING around
A hybrid MPPT inverter
50 kwh of Lifepo4 batteries

We can NOT Net Meter, but we CAN connect to grid to consume power. .

BUT, though we have 3 phase service, usually one phase is down.

we consume about 40-80 kwh a day.

Electricity has gone up 400% here in the last year, its almost a US DOLLAR PER KWH (yep, nuts).

Most of our loads are single phase, except 2 large heat pumps, and the Electric vehicle charging station, which are 3 phase.

We can't go totally off grid as we would need huge 150-200 kwh batteries, expensive, and need lots of space.

So we need to design a system that can charge as much as possible during overcast/cloudy days.

And we also need to be able to charge our batteries from just a single phase from the Grid.

Its kind of a tricky situation, and hoping you experienced ladies and gentlemen can help give me some advice and solutions.

thank you!

 

[timselectric]

You just need off grid AIO's. Stacked in sets of 3 for 3-phase. Each one can charge from its own phase. So if one grid phase is down, it only affects 1/3 of AC charging. The other option is a single unit for 3-phase. But you loose the ability to utilize single-phase from the grid.

 

[houseofancients]

You just need off grid AIO's. Stacked in sets of 3 for 3-phase. Each one can charge from its own phase. So if one grid phase is down, it only affects 1/3 of AC charging. The other option is a single unit for 3-phase. But you loose the ability to utilize single-phase from the grid.

that, or a true hybrid that supports zero export.
they come in 3 phases, but the maximum for those would be 12kw peak, so you would assumably need more than one.

@OP please take a look at Deye or Sunsynk, they would tick all of you boxes, and have local EU resellers

 

[timselectric]

If you aren't going to export or AC couple. There's no need for a hybrid. Unless, it's a cheaper option in your location. And if you choose a 3-phase unit, I don't think it would be happy with one phase down.
Deye/ SunSink are quality units. But you are paying for functions that you won't use.

 

[houseofancients]

If you aren't going to export or AC couple. There's no need for a hybrid. Unless, it's a cheaper option in your location. And if you choose a 3-phase unit, I don't think it would be happy with one phase down.

it probably is, and more importantly , eu warrantee and dealers...

these will go into off grid mode if a phase fails

 

[timselectric]

these will go into off grid mode if a phase fails

But, they want to still charge from the grid when only single phase is available.
They could add a separate AC charger. But this also adds cost.

 

[PreppenWolf]

Mounting the panels flat is fine for July, but you're going to get slaughtered any other time of year. This is solar hours with horizontal mount for Edessa.

 

[PreppenWolf]

Your panels need to be around 60 degrees from horizontal to get the max 2.5hrs of sun in December.

 

[houseofancients]

But, they want to still charge from the grid when only single phase is available.
They could add a separate AC charger. But this also adds cost.

yeah, er no, that might not be such a great plan.
of course op could hookup a single phase charger, but when a phase goes down, usually the remaining are either really high on voltage or low, effectively eventually killing everything connected..
one shouldnt play around with 380v

 

[PreppenWolf]

Here is weather summary for Edessa. OP didn't give a location other than Northern Greece, so I picked Edessa randomly.

Overcast 52% of days in December.

Édessa Climate, Weather By Month, Average Temperature (Greece) - Weather Spark

In Édessa, the summers are warm, dry, and mostly clear and the winters are very cold and partly cloudy. Over the course of the year, the temperature typically varies from 30°F to 88°F and is rarely below 20°F or above 96°F.

weatherspark.com

 

[sunshine_eggo]

Hello,

I have a farm and large property in Northern Greece. At the moment we have 3 phase grid power, and a 50 KVA generator on a transfer switch, which gets used a lot since the grid is very unstable in our particular area.

I am in the process of specifying a system and was hoping for some suggestions and advice since you folks have experience, and its better to get the right stuff now rather than fix the wrong install later.


20 KW in panels, 550W mono panels, Mounted on a flat roof with NO SHADING around
A hybrid MPPT inverter
50 kwh of Lifepo4 batteries

We can NOT Net Meter, but we CAN connect to grid to consume power. .

BUT, though we have 3 phase service, usually one phase is down.

we consume about 40-80 kwh a day.

Electricity has gone up 400% here in the last year, its almost a US DOLLAR PER KWH (yep, nuts).

Most of our loads are single phase, except 2 large heat pumps, and the Electric vehicle charging station, which are 3 phase.

We can't go totally off grid as we would need huge 150-200 kwh batteries, expensive, and need lots of space.

So we need to design a system that can charge as much as possible during overcast/cloudy days.

And we also need to be able to charge our batteries from just a single phase from the Grid.

Its kind of a tricky situation, and hoping you experienced ladies and gentlemen can help give me some advice and solutions.

thank you!

some poor frenchman is in the same boat...

Help running a farm almost off grid - VictronEnergy

community.victronenergy.com

 

[PreppenWolf]

some poor frenchman is in the same boat...

Help running a farm almost off grid - VictronEnergy

community.victronenergy.com

Someone should tell that guy climate change didn't raise his electric prices. That was government.

 

[houseofancients]

Someone should tell that guy climate change didn't raise his electric prices. That was government.

well no, not really, it was certain dellutional russian semi dictator invading other countries causing shorting on eu markets.. it is called capitalism

 

[PreppenWolf]

Capitalism didn't make Europe shut down their power plants and rely on Russians for power. Their own governments did that. Russia benefited for certain, but Russia didn't make Europe hand over its energy independence on a silver platter. Europe CHOSE to do that over the fictional climate change narrative.

 

[houseofancients]

Capitalism didn't make Europe shut down their power plants and rely on Russians for power. Their own governments did that. Russia benefited for certain, but Russia didn't make Europe hand over its energy independence on a silver platter. Europe CHOSE to do that over the fictional climate change narrative.

oh dear lord

fictional climate change narrative.

science and climate denier i guess.
never mind , not going there

 

[PreppenWolf]

@greeksolar how many kWh per day average do you want to generate?

 

[Shimmy]

Seems like you have a good environment for bifacial panels. I would use off-grid inverters and multiple cheap 48V grid-connected chargers. Do you know your day/night energy consumption balance?

 

[greeksolar]

Here is weather summary for Edessa. OP didn't give a location other than Northern Greece, so I picked Edessa randomly.

Overcast 52% of days in December.

Édessa Climate, Weather By Month, Average Temperature (Greece) - Weather Spark

In Édessa, the summers are warm, dry, and mostly clear and the winters are very cold and partly cloudy. Over the course of the year, the temperature typically varies from 30°F to 88°F and is rarely below 20°F or above 96°F.

weatherspark.com

Hello, Thessaloniki

 

[greeksolar]

Seems like you have a good environment for bifacial panels. I would use off-grid inverters and multiple cheap 48V grid-connected chargers. Do you know your day/night energy consumption balance?

The roof is totally white and reflective, I was thinking of bifacial. Most consumption during day, but still have base loads at night. Swimming pool pump four refrigerators, heating or cooling, etc

 

[greeksolar]

@greeksolar how many kWh per day average do you want to generate?

Well we consume 50 to 70 most days

 

[greeksolar]

Capitalism didn't make Europe shut down their power plants and rely on Russians for power. Their own governments did that. Russia benefited for certain, but Russia didn't make Europe hand over its energy independence on a silver platter. Europe CHOSE to do that over the fictional climate change narrative.

I agree, piss poor government planning. Ridiculous

 

[greeksolar]

Mounting the panels flat is fine for July, but you're going to get slaughtered any other time of year. This is solar hours with horizontal mount for Edessa.

View attachment 137296

The roof is flat, I wasn't planning on mountin
g the panels flat.

 

[ImAnIdiotPleaseBePatient]

Sandi makes 50-250kw inverters that can run with grid assist function and won't backfeed. Prices are fair. Batteries are expensive for it (HV) but I would just say screw the batteries, and undersize the array to cover ~50-70% of your needs. Inverter will combine grid power with solar.

 

[timselectric]

Sandi makes 50-250kw inverters that can run with grid assist function and won't backfeed. Prices are fair. Batteries are expensive for it (HV) but I would just say screw the batteries, and undersize the array to cover ~50-70% of your needs. Inverter will combine grid power with solar.

They work with DIY batteries.

 

[PreppenWolf]

Here is over all weather.

Thessaloníki Climate, Weather By Month, Average Temperature (Greece) - Weather Spark

In Thessaloníki, the summers are hot, dry, and mostly clear and the winters are very cold and partly cloudy. Over the course of the year, the temperature typically varies from 34°F to 90°F and is rarely below 25°F or above 96°F.

weatherspark.com

This is the most relevant part for estimating solar output.


Here is solar equivalent hours for 25degree from horizontal exactly south facing.


Here is solar equivalent hours for 50degree from horizontal exactly south facing.


Don't go more than 50deg as you won't gain more than 1% in December and you'll sacrifice in all other months. 25deg seems like a reasonable low number to not sacrifice more than 2-3% of July.