Small solar advice (5KVA hybrid system)

[isie]

Not even close. Two Hisense fridges (one bought last year) and one Defy freezer, all "A" energy rating and still being sold today.

Guess it's just the compressor starting up high, running power is low.

I have a hi sense fridge freezer combo that thing uses less then some of my light bulbs (lol sarcasm) but seriously my home base load is low - i think with most stuff including the fridges like high of under 700w (2 fridge / freezer combos and 1 single Fridge (not even an efficient deep freezer) only kicks up to the 2 kw+ mark when the kettle or air fryer and 3kw+ when geyser or oven is used - most of the time under 500w

 

[Lupus]

I have a hi sense fridge freezer combo that thing uses less then some of my light bulbs (lol sarcasm) but seriously my home base load is low - i think with most stuff including the fridges like under 700w (2 fridge / freezer combos and 1 single Fridge (not even an efficient deep freezer) only kicks up to the 2 kw+ mark when the kettle or air fryer and 3kw+ when geyser or oven is used

Yeah my base load is 300 to 500w. Then you've got some on here who's base load would be like 150.
Fridges use very little even on defrosting it'll maybe go to 180w but it only runs every so often. Freezer on the other hand runs at 50w most of the time

 

[isie]

If I go with your version of blending vs how I understood Wingnuts one, then no. I don't think mine did that type of blending. It would use PV, if not enough, then PV and battery until the battery is drained to whatever level you set. Then switch to supply the load with 100% grid. Available PV that's left as the sun goes down then only charges the battery. You could say it is a good option to have PV and a grid blend to supply the load until the PV is gone.

You still use all the PV on the cheapies, though, as the PV was still used to charge the battery until it completely disappeared, then, depending on your settings, it would charge the remaining amount from the grid or wait for the sun the following morning to finish off the charging.

trust me having had to run only PV no battery for a couple of weeks the blending saved me a bit of cash

 

[denmendez65]

I have a hi sense fridge freezer combo that thing uses less then some of my light bulbs (lol sarcasm) but seriously my home base load is low - i think with most stuff including the fridges like high of under 700w (2 fridge / freezer combos and 1 single Fridge (not even an efficient deep freezer) only kicks up to the 2 kw+ mark when the kettle or air fryer and 3kw+ when geyser or oven is used - most of the time under 500w

Low is relative ...This is the house. Outdoor fridge looks to be running. The kitchen tops out at 80W (mainly when the fridge in the kitchen is running) until a toaster etc. is run. To me 700W at night I would be getting worried lol

 

[denmendez65]

trust me having had to run only PV no battery for a couple of weeks the blending saved me a bit of cash

I still think there is no difference. Your scenario blends the grid with PV.

Axperts blend battery and PV until the battery hits cut off, at which point the grid completely takes over, but all the PV is still captured by the inverter as the PV charges up the battery. If you have enough battery capacity on an Axpert, the grid never gets used. Yours will still shift to the grid when the battery cut-off is hit. There is no difference from a grid consumption perspective.

 

[wingnut771]

Nope my old one blended solar, battery and grid where needed.

Good to know. Which one was that?

 

[isie]

Low is relative ...This is the house. Outdoor fridge looks to be running. The kitchen tops out at 80W (mainly when the fridge in the kitchen is running) until a toaster etc. is run. To me 700W at night I would be getting worried lol
View attachment 1901164

thats my high with everything running. at night is way under

I still think there is no difference. Your scenario blends the grid with PV.

Axperts blend battery and PV until the battery hits cut off, at which point the grid completely takes over, but all the PV is still captured by the inverter as the PV charges up the battery.

If you have enough battery capacity on an Axpert, the grid never gets used.

same with mine?

Yours will still shift to the grid when the battery cut-off is hit.

so will an expert though - only difference is grid will be less

There is no difference from a grid consumption perspective.

ya i think its more on how its used - maybe anecdotal but seem to be more efficient for me

 

[Lupus]

Good to know. Which one was that?

The Mecer Axpert thingy ma bob

 

[denmendez65]

thats my high with everything running. at night is way under


same with mine?

so will an expert though - only difference is grid will be less

ya i think its more on how its used - maybe anecdotal but seem to be more efficient for me

I think you misunderstood me.

When PV is low, the fancy inverters will blend grid and Pv. Battery stays full.

Axpert will blend battery and PV.

If battery cut off is hit during the day and the MPPT is still on, Axpert will switch to grid and supply load with 100% grid but the PV that is still coming in is used by the inverter to charge the batteries. If the MPPT switches off due to low light then it will finish off the charging with the grid. But at no point is the Pv wasted.

The fancy inverter during the time the Axpert was running off the battery was using the grid and PV until the PV is gone and then it uses PV and battery. But the same Pv used by it is the same one used by the Axpert. Only difference is the battery stayed full throughout.

Basically the kWh used by both inverters from the Sun and Grid is the same. Maybe difference is the efficiencies. It’s just a difference of appproach that’s all.

Blending to me is fancy Jargon used by manufacturers to say heir inverter is better than the other brand but when you go into details there really isn’t much difference

 

[wingnut771]

I think you misunderstood me.

When PV is low, the fancy inverters will blend grid and Pv. Battery stays full.

Axpert will blend battery and PV.

If battery cut off is hit during the day and the MPPT is still on, Axpert will switch to grid and supply load with 100% grid but the PV that is still coming in is used by the inverter to charge the batteries. If the MPPT switches off due to low light then it will finish off the charging with the grid. But at no point is the Pv wasted.

The fancy inverter during the time the Axpert was running off the battery was using the grid and PV until the PV is gone and then it uses PV and battery. But the same Pv used by it is the same one used by the Axpert. Only difference is the battery stayed full throughout.

Basically the kWh used by both inverters from the Sun and Grid is the same. Maybe difference is the efficiencies. It’s just a difference of appproach that’s all.

Blending to me is fancy Jargon used by manufacturers to say heir inverter is better than the other brand but when you go into details there really isn’t much difference

Fancy inverters (sunsynk) blend with battery down to your set minimum soc setting for that time of the day then will use grid.

 

[denmendez65]

Fancy inverters (sunsynk) blend with battery down to your set minimum soc setting for that time of the day then will use grid.

So do Axperts. But not to a specific time setting if that’s what you mean.

 

[wingnut771]

So do Axperts. But not to a specific time setting if that’s what you mean.

Yeah, you can set time slots with different soc settings.

 

[denmendez65]

Yeah, you can set time slots with different soc settings.

That is actually very useful.

The only reason I started running the whole house using the batteries at night was because I didn't have that flexibility with setting times. Mine would only switch to grid when the cut off was hit. I wanted solar during the day and grid at night. Eventually gave up and let the house run off batteries till morning. Realised I actually could just fine so didn't bother me after that.

If I had the flexibility of the fancier ones I doubt I would be off grid right now since the original intention was backup power, not running the house off batteries. The inverter's inflexibility in that regard led down the rabbit hole to going off-grid. Can't complain though, but it did annoy me back then.

The 2kW Fivestar could switch to grid automatically when the PV was gone which is what I wanted from the Axpert.

 

[wingnut771]

That is actually very useful.

The only reason I started running the whole house using the batteries at night was because I didn't have that flexibility with setting times. Mine would only switch to grid when the cut off was hit. I wanted solar during the day and grid at night. Eventually gave up and let the house run off batteries till morning. Realised I actually could just fine so didn't bother me after that.

If I had the flexibility of the fancier ones I doubt I would be off grid right now since the original intention was backup power, not running the house off batteries. The inverter's inflexibility in that regard led down the rabbit hole to going off-grid. Can't complain though, but it did annoy me back then.

The 2kW Fivestar could switch to grid automatically when the PV was gone which is what I wanted from the Axpert.

My minimum settings for all the time slots vary between 10 and 20% soc so am using all battery anyway same as you. Im shocked you say you wouldnt go off grid. That means you are paying R1.5k per month line fees.

I think your must inverter has a bug.

 

[denmendez65]

My minimum settings for all the time slots vary between 10 and 20% soc so am using all battery anyway same as you. Im shocked you say you wouldnt go off grid. That means you are paying R1.5k per month line fees.

I think your must inverter has a bug.

Well it is a Clone at the end of the day and all of them when I researched had the issue of not switching to grid when the Sun went down. The brand is a bit over 7 to 8 years old but even the new ones do the same. Maybe its just how they want it to work, not sure. They make the Ecco Inverters also.

All the other typical functionality is there except that one thing and the extra stuff from the very fancy inverters. You need to set a high SOC cut off for it to switch to Grid but it limits your savings. Setting lower allows more savings if set to charge only from solar but if your bank isn't big enough to last the night you run into trouble with power cuts.

On the off-grid part I always thought it was impossible to do so and reading online they would say you need to spend some 300k to do so. The "bug" changed my perspective since it allowed me to see that it was possible. A fancy inverter would have left me with doubts about being able to do it as I would default to using the grid at night. I was basically like the OP. No grande ambitions, just a simple setup.

Edit: MUST the company is actually 16 years old. So it cant be a bug. That is probably how they want the inverter to work.

 

[cavedog]

I still think there is no difference. Your scenario blends the grid with PV.

Axperts blend battery and PV until the battery hits cut off, at which point the grid completely takes over, but all the PV is still captured by the inverter as the PV charges up the battery. If you have enough battery capacity on an Axpert, the grid never gets used. Yours will still shift to the grid when the battery cut-off is hit. There is no difference from a grid consumption perspective.

I don't understand what you guys are talking about with this blending story? The Axpert clones which most will say qualifies as cheapies do blending just fine.

 

[cavedog]

I believe it is actually a 4kW, not 5. That is what Cavedog said at least.

Hybrid Inverter 48v 6.2 Kva 6200w MPPT 120A Inverter Pure Sine Wave -

Hybrid Inverter 48v 6.2 Kva 6200w MPPT 120A Inverter Pure Sine Wave - Ecco The main difference between PWM and MPPT charge control devices is that the MPPT devices are more efficient. MPPT charge control devices have 30 % more efficient in charge efficiency according to PWM type. Panel voltage...

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I would go for the Ecco. 5200 rand for a 6.2kW. My Dad is off-grid with this inverter. 120A MPPT at 500Vdc so you can add over 5/6kW of panels without issues. Its a true 6.2kW with 2x the surge rating. They have never tripped it and he welds, runs 3kW borehole pump etc on it with zero issues.

Interestingly my test today proved it can do more that 4kW on AC conversion if I cut off the grid supply.

I ran my pool pump + geyser so the load was 4.35kW. When grid was on 4kW came from Solar and Battery because PV was like 3.8kW and and the 350w came from grid.

When I turned the breaker off that feeds grid to the inverter, I heard the relay click and the entire load 4.35kW came from the inverter and it didn't overload. I switched the aircon on also and it did 4.9kW and still didn't moan about overload so I'm not sure why if it's got grid does it not want to invert more than 4kW. Still need to figure out if that is a setting or by design.

 

[leon.davibe]

Let’s clarify why you need hybrid? Only if you want to feed back into the grid does one need hybrid afaik. A R4k 5kW nava solar inverter from Amazon would do the same thing in powering essentials.

The off grid types require more work to save power

And often they can't be set to switch to grid on specified SOC %

Often they have to be set via voltage which isn't lifepo4 friendly

So with a set it and forget it setup for non tech savvy people the premium paid will be worth it

Remote management will also help a lot, which cheapies often don't

 

[denmendez65]

Interestingly my test today proved it can do more that 4kW on AC conversion if I cut off the grid supply.

I ran my pool pump + geyser so the load was 4.35kW. When grid was on 4kW came from Solar and Battery because PV was like 3.8kW and and the 350w came from grid.

When I turned the breaker off that feeds grid to the inverter, I heard the relay click and the entire load 4.35kW came from the inverter and it didn't overload. I switched the aircon on also and it did 4.9kW and still didn't moan about overload so I'm not sure why if it's got grid does it not want to invert more than 4kW. Still need to figure out if that is a setting or by design.

I genuinely don’t recall mine doing the blending stuff which yours seems to be doing. But then again maybe my settings were wrong. I didn’t want the grid used during the day.

And that’s good to hear. It would make sense that it’s a 5kW if the spec says that. Maybe you just hadn’t run enough load to test that last time.

 

[denmendez65]

@cavedog Yeah even my manual says that option isn’t there.