In spite of it raining and being totally overcast, its produced enough Solar to support the house base load, and charge the battery with a few Amps. The grid value is the bottom floor as its not yet wired to the inverter output. The 1st floor is AC loads.

 

Edited October 1, 20214 yr by Sarel
Added charging

My weather station have solar insolation measurement capability. It’s outside calibration specs now but still within a few % 

 

for my measured 721W/m2 I get 7118W energy out of 30 panels that should give me 12 510Wp out of an area of 58,2m2. The solar insolation on this area is therefore 41 962,2W or ~42kW so the efficiency is roughly 16.96% Not bad for this time of year or my specific setup.

 

Solar radiation and heating/cooling degree days. Grabbed some info from my weather station. Cooling base temp is set to 19degC and heating to 28degC The correlation between Solar energy, temps etc is easily visable.

 

 

It's currently raining here, and this is the performance, not to bad for completely overcast raining weather....

 

As per design, the 6 panels in the front gets Sun before the other strings as it is the DC coupled panels, directly charging the battery bank. 06:30 24 Oct.

So 6 x 385W panels are generating 59,94% of the solar compared to the 24 x 425W panels this early in the AM. 🤠 100% Success! 

Some report back. The last few days in Centurion was mostly raining or overcast. On top of that we had blackouts, Stage 2 and then at 12:00 today went to Stage 4. With my system we still managed to charge 8kWh worth and get the battery bank full, also consumed the generated energy. This was planned for by over dimensioning the array to allow for exactly that. The system she works  and the family is happy, in turn I am as well... Life continues despite the CancER and their ineptocrasy.

 

Storage, batteries really or angry pixie containment ;/

 

Edited October 29, 20214 yr by Sarel
wrong place

Time for some comparisons, and analysis with graphs, here we go....

As you know, I use a Micro grid here. It consists of a Victron Quattro with the Fronius Grid-tie on it's AC output, an AC coupled system. There is also, as part of this, a Victron PV Charger MPPT controller. It exclusively charges the battery bank.

The PV charger can handle 150V @ supply 48V @ 35 Amp. There are 6 x 385Wp panels configured as 3S2P string on it's input for 2310Wp. We normally get 1945W peak power from this string as per the below graph. This on a mostly cloudless day.

 

And this shows the yield in kWh.

 

Now on to the Fronius and it's dual MPPT's. The yield here was 61kW from 10.2kWp panels and the Fronius can deliver 8.2kW output power. The dip in output on the small string is the MPPT controller reducing it's output to keep the Fronius locked at it's max output capacity.

 

The total yield for all 3 strings at 12510kWp for this day is below. We get 10.2kW out of both systems.

 

On a cloudy day, expect this....

 

This is the combined output as on 9 November, a cloudy and windy day.

The temps on my PV charger were to high due to my mounting position. So I created an extra heat sink and bolted the MPPT to that. There are pictures in an earlier post on here. Having monitored the MPPT temps for a few weeks, It's still to hot to my liking. Did a quick and dirty AC fan blowing over it experiment, and with my heat sink mod and fan, the temps dropped by another 20C.

So now the next mod is planned.

This is showing the strain relief and wire protective cover for the PV charger. My plan is to power a temp controlled set of mini fans to force air between the heat sink on the MPPT and my plate. I want to power this direct from battery 48V as even if the Utility is down and my inverters are down as well, the PV charger will still power and charge the battery system, even with no AC supply as it's DC coupled. That means that it will need cooling while charging. As long as we have Solar on the MPPT, it will power the fan as its connected to the output of the MPPT. Temp will regulate the fan speed.

These are the fans: 2 x Noctua NF-A4x20 PWM, Premium Quiet Fan, 4-Pin (40x20mm). Them lil buggers are super quiet, and very efficient, with low power consumption and a lot of air volume @ 135L/min.

Premium quiet fan, 40x40x20 mm, 12V, 4-pin PWM, max. 5000 RPM, max. 14.9 dB(A), >150,000 h MTTF.

And the fan controller. It can take 11-55VDC as input. So now to build a fan duct, maybe bend it up or CAD one and 3D print, will see....

43 minutes ago, Sarel said:

The temps on my PV charger were to high due to my mounting position. So I created an extra heat sink and bolted the MPPT to that. There are pictures in an earlier post on here. Having monitored the MPPT temps for a few weeks, It's still to hot to my liking. Did a quick and dirty AC fan blowing over it experiment, and with my heat sink mod and fan, the temps dropped by another 20C.

So now the next mod is planned.

This is showing the strain relief and wire protective cover for the PV charger. My plan is to power a temp controlled set of mini fans to force air between the heat sink on the MPPT and my plate. I want to power this direct from battery 48V as even if the Utility is down and my inverters are down as well, the PV charger will still power and charge the battery system, even with no AC supply as it's DC coupled. That means that it will need cooling while charging. As long as we have Solar on the MPPT, it will power the fan as its connected to the output of the MPPT. Temp will regulate the fan speed.

These are the fans: 2 x Noctua NF-A4x20 PWM, Premium Quiet Fan, 4-Pin (40x20mm). Them lil buggers are super quiet, and very efficient, with low power consumption and a lot of air volume @ 135L/min.

Premium quiet fan, 40x40x20 mm, 12V, 4-pin PWM, max. 5000 RPM, max. 14.9 dB(A), >150,000 h MTTF.

And the fan controller. It can take 11-55VDC as input. So now to build a fan duct, maybe bend it up or CAD one and 3D print, will see....

Noctua fans are legendary for their quietness.

So , Sarel , I haven't stepped foot on your thread for a while, but I see you have in essence completed and commissioned , now your gauging performance and adjusting/tuning.congratulations. hope for your sake  everything is not 100% , because what are we ou toppies going to do , when there's nothing to do.😁

You are a Turnkey Solutions Provider, System Integrator, Consultant.

All in One , Mums😁😁

Edited November 11, 20214 yr by dropkick

Absolutely love the details!!

Incredible work Sir Sarel!!

On 2021/11/08 at 9:09 AM, Sarel said:

...So now to build a fan duct, maybe bend it up or CAD one and 3D print, will see....

If you need some assistance with 3D Printing, I have large 400x400x400 capable machines.

Thank you Sir! My 3D printer is not quite that size at 250x235x160 but good for my needs. It can also do cnc router and cnc laser as well. Will shou if I need a moster sized print tho 👌🏻

Hi Sarel, 

love the work and setup, have you managed to get your victron talking nicely with the energy component of home assistant ? I’ve searched high and low but haven’t found a decent way to integrate the sensors into that component. I’ve got my other victron stuff all setup but this piece eludes me

In the Energy dashboard I could only get the MPPT PV charger data integrated. That said however, I used the type: custom:power-distribution-card from github to get an easy to read dashboard. The EnergyFlows below.

So prepping to add some more components that were not available at the time of installation. Still awaiting a contactor, proper Marine grade battery switches and a few other parts arrival.

Ground/Earth monitoring:

As explained in my other thread (https://powerforum.co.za/topic/10227-new-solar-planning-and-design-guidelines/) the Earth connection is vital.

So I decided to use this device from Cirprotect. The PSM SAFEGROUND DIN rail device is for monitoring the earthing system from within the actual surge protection device. This is my main Utility grid protection.

Next to be added was clear indication of what type of power was active as we have 3 different sources, Generator, Solar and Utility grid.  The Schneider Pilot lights will show the active ones. Also installed another one in my Main DB apart from what I showed here.

 

That was a good read for a Sunday morning. 👍

Tackled the last bits of the AC side yesterday. Added the pilot light wiring and re-arranged the main DB as it was stuffed over full. Moved the Astute switches to a new DB where the pilot lights are, next to the main DB. Also wired the sub DB pilot lights.

Still outstanding are the Main DB labling, some other labelling and to add a second RCD for my workshop and outbuildings. Also still need to add heat shrink to my busbar outputs where the inverter cabling attaches. But that requires a total shutdown of everything, so planning to do that when the new battery modules arrive.

 

The Sub DB for solar has this Generator control DB. Pilot lights are Green for Solar, Red for Utility grid from Escam and Yellow for Generator. I still need to add the contactor for Utility grid lockout when the Generator runs.

Sarel,

 

I probably missed the reason , but why did you go for the 

• Fronius Primo 8.2kW and 
• Victron Quattro 8kW

instead of 2 of the same brands.

Gladly, the Quattro is a battery inverter and the Fronius is a Grid tied string inverter. Now Victron do not make hybrid or Grid tie inverters. Victron and Fronius have out the box exceptional integration.

What the Fronius does is very efficiently generate AC directly from the panels. But the Fronius is dependent on a grid being available. So I use the Quattro to form the grid when the Utility is not present for whatever reason.

The Fronius connects to the Quattro AC output, not input, and can then still generate energy from the panels even when the Utility fails as it works on the Quattro’s grid from battery.

When you do this, it’s called a Micro grid, your battery inverter, the Quattro in my case needs to be of the same power (8kW) as the Grid tied inverter on the Quattro’s output. There is a rule called the 1:1 rule dictating the the Grid tied inverter cannot be any bigger than the Quattro.

So why the Quattro? It has dual AC inputs and dual outputs. They can be paralleled for more power and/or 3 phase. They don’t have MPPT controllers build in. They can be used in a Micro grid and do 0 energy feed in to the Utility grid in conjunction with the Fronius.

The Fronius have dual MPPT controllers and I have the extra Victron MPPT PV charge controller with its own panels as a direct DC coupled system to only charge batteries.

 

OOOKKK, 

 

Thanks for the explanation 

On 2021/07/23 at 9:05 AM, Sarel said:

Some more food for thought, since the new CEO started in beginning 2020, the unplanned outages at eScam has increased by ~4% :O, not decreased at all as lots of preventative maintenance may indicate. It is now 18 months since we were told that all the extra maintenance will be done. We had all the load shedding blackouts that were ascribed to maintenance. Not successful I would say…. But draw your own conclusions from the data. Also please validate and do your own investigations to prove or disprove the data presented, for yourself. You are welcome Also, these are just my thought processes, nothing wrong with any of the systems on here, just your compromises. My compromise was just on the money side as I chose to pay more to get exactly what I wanted. This is just my way of going about building my system around my needs and my compromises and maybe this can help people to make easier choices and understand why they make em. Lots of professionals on here with better or other ideas and all the more power to them Over the years I have learned a lot on here, consider this my contribution to the community, for what its worth. 

But now we talk Micro grid, aka mini me grid  or your own utility.

 

I want to say again, I love projects, I really do and I work on lots of them at the same time. This Solar PV however cannot be a project, not so much as its the foundation for everything else, hence my choices here.

To start let’s look at the cheapest way to self generation and consumption, ie Grid tie systems. This is one of the fundamental systems together with Off grid and Hybrid systems. What are the problems of a Grid tie system? When the grid goes down, blackouts happen and then your Solar PV system goes down, by design. Just ask the People in Texas. The anti-islanding shuts down the Inverter, as it should from a safety standpoint. So without the grid it’s useless. Off grid systems add Storage (batteries) and are not connected to the utility grid at all. A hybrid system is a bit of both, ie Grid tied with Storage. Same problem exists for Grid tied Hybrid systems in that the Solar PV will disappear for some or most (depending on Inverter Architecture) if there is no grid and the Inverter cannot be connected to the downed grid. The system will dump all non essential loads when the grid disappears too.  Also your hard limit is the Hybrid Inverter capacity.

Enter the Micro grid. Essentially this means that your String Grid tied inverter must have a stable grid input of the required 50Hz frequency to function. The Inverter Charger and battery bank can supply this if the Grid tied string inverter is coupled on the output of the Inverter charger, Critical load position below or PV on AC output. If you connect it to the AC input, it will die with the grid. This is called AC coupling and can be used to inefficiently charge the batteries in the event of no grid. The inefficiency is due to the DC panels being inverted to AC and then again to DC with all their losses. There also may be battery assist where the Inverter/Charger will support the String Inverter by adding more power from the batteries to support the loads. There are all sorts of rules and caveats here and we can unpack those later.

DC coupling (Black start capability) is when the panels are connected to a MPPT controller direct to the DC battery side. Its way more efficient to charge batteries that way as there are no dc to ac inversion and back to dc. Effectively a Micro grid (there are larger versions of this called mini or metro grids that supply multiple consumers or homes) is a mini me Eskom, independent of Eskom. You can under certain conditions in a Micro grid, expect to get extra kW support from the batteries in addition to the String inverter’s power output, up to the limit of the Inverter thus adding between 1 and 100% of the power from batteries, but with lots of ifs and buts and caveats in there.

PS: I am not affiliated with any company at all, its merely convenient to use my own system as example. I paid full retail for.

My system is a Micro Grid with the Victron Quattro 8kVa and Fronius Primo 8.2 single phase string inverter on the Quattro AC output, thus creating my own Micro grid. I follow the 1:1 rule for adding a Fronius on the Quattro’s output. That means you are not allowed a String Grid tied inverter of larger capacity than the Quattro, in my case at 8kVa, hence the Fronius 8.2 Primo. I am still going to be connected to the Utility grid in the meantime. I will go Off grid when my BYD storage has been expanded with enough capacity to last a full dark Winters day and night.

I am using both AC (Victron & Fronius) coupling as well as DC coupling (MPPT charge controller on DC Bus) to allow the sun to charge and start the system in case of no grid and depleted battery. And yes you are correct, I can wait for the grid to return to start the system or run the generator. As explained, I do not want to be dependant but rather independent from the Grid and also do not want to mess with the system. Black start capability will automatically recover the system as the Fronius will need a grid at 50Hz to start, and take up the load. The DC MPPT system can charge the batteries even with Grid down and batteries depleted allowing the Quattro to boot and provide the grid again. 

More to follow....

Sarel,

Is your PV array still 11.6kW ?

Are the 2.3kW  sufficient to charge your batteries within 6 hours

Is the Fronius also used to charge the batteries ?

 

Edited November 21, 20214 yr by Bluefronted