The Alternative Energy Thread - Generators, Solar, UPS, Wind

[mgalaxy3]

How do you guys manage heavy loads like ACs on hybrid inverters.

They should run on solar when enough generation is available but when inverter switches to battery for backup (both solar and grid not available or not enough), then heavy appliances should be disconnected automatically. Light loads should continue to power from battery.

Some inverters have two ports, GEN / smart load and one more.

Can this be managed via this setting and if so how?

@umans @AkbarGr8 @centos @noobie / other experts I might have missed.

[AkbarGr8]

Salaam, I do not have a hybrid inverter but I can comment on how this can be achieved.

You're correct - the gen / smart load port can be used to achieve this and your electrician will need to manage load on it accordingly. This is essential, to prevent the inverter from tripping even when there is power.

There are settings in the inverter through which you can set battery % at which it will turn off the heavy load during an outage and drain the battery during normal operating procedures, i.e. peak hours.

One thing that most installers miss is that a compatible lithium battery needs to be installed to make the most of this feature, i.e. BMS should work and there should be communication between the inverter and battery.

Manually setting voltages only gives approximate power values which in my opinion should be avoided.

In case of inverex, to the best of my knowledge pylontech batteries are compatible and perhaps its on powerwall - please confirm from installer.

Good luck!

[sardarg]

sirs @akbargr8 a solar integrator ahmed working in karachi malir cantt & saadi town area mostly, always tell his customers to shut down airconditioners at 4.30 pm. That is to avoid short back up time from batteries during load shedding. He always recommend to use washing machine, iron before 4 pm, to avoid battery sharing on heavy load.

it is quiet obvious that the inverter always share batteries automatically when the generation from sunlight is not enough to handle running load. Thereby the battery backup time reduced significantly after sunlight hours.

[AkbarGr8]

I think this is a inverter source setting issue. To save battery, I believe the priority should be set to Solar, Utility, battery.

I.e. first preference to solar, then Utility and lastly battery.

Installer can comment on this best

[AkbarGr8]

Fyi Narada new battery type BMS working with new Inverex inverter, found this on random solar group.

[noobie]

I am using Heavy Load (Gen) port for this. All the AC's and other high wattage appliances are connected to Heavy Load port and they automatically shut down when certain parameters are met (offgrid mode && solar production < 2000W && battery % < 98%). Heavy Load (Gen) port will always have output if grid is available.

[mgalaxy3]

Thanks @AkbarGr8

And @noobie what battery are you using, tubular/lead acid or lithium?

I guess one can’t set battery percentage if not using lithium..

In my case i have set voltage cutoff point but it doesn’t seem to be working properly.

[AkbarGr8]

A lithium battery would behave as a regular battery if the BMS isn't functional (i.e. will need voltage cutoff points).

[noobie]

I'm using tubular. I have setup the cut off value in voltages (51.5) - This causes almost immediate cut off of the heavy load as soon as the solar production drops and if grid is not available. Which inverter are you using?

[umans]

If your inveter has dual output, you can achive this by configuring battery threshold on smart load port.
If inverter has only one output port, there are is device available with name SDO device to achive the same.
Please share the exact scenario or issue so I can better understand and help.

[shakeel9045]

Friends,

These questions are related to hybrid inverters running in parallel, i am interested in solis inverters so anyone having experience with solis inverters please advise me.

Are there any drawbacks in installing solar inverters in parallel other than higher capital?
Is it possible to combine inverters of different wattage lets say an 8kw with 6kw?
Are the slaves powered by the master or they need to be powered separately?
How do i determine what ampere hour (AH) batteries should be used in the system?

[mmew059]

If your UPS batteries are getting drained quickly despite being only six months old, there are several steps you can take to diagnose and potentially resolve the issue before considering replacement:

1. Check Battery Connections and Terminals: Ensure all connections are tight and free from corrosion. Loose connections or corrosion can lead to poor electrical contact and rapid discharge.

2. Inspect Battery Condition: Physically inspect the batteries for any signs of damage, leakage, or bulging. Damaged batteries can lead to faster discharge rates.

3. Measure Battery Voltage: Use a voltmeter to measure the voltage of each battery individually when the UPS is in normal operation (fully charged state) and when it is discharging. A significant drop in voltage during discharge indicates a problem with the battery.

4. Load Test the Batteries: Perform a load test on each battery. This involves applying a controlled load to the battery and measuring how long it can sustain that load before voltage drops to a critical level. This test helps determine if the batteries can hold their charge under load.

Regarding your question about "acid mixture replacement," if you are referring to adding distilled water to flooded lead-acid batteries (such as Exide batteries), this is a standard maintenance task. Over time, water evaporates from the electrolyte, and topping it up with distilled water can help maintain proper electrolyte levels. However, this typically doesn't resolve issues related to fast discharge unless the low electrolyte level is causing poor battery performance.

If after performing these checks you find that the batteries consistently show signs of weakness (e.g., rapid voltage drop under load, inability to hold charge), it might indicate that the batteries are indeed deteriorating and nearing the end of their life. In such cases, replacing the batteries would be the most effective solution to restore UPS performance and reliability.

[AkbarGr8]

Hi, looking for roof rails to mount solar panels (see attached picture). Any suggestions regarding sourcing?

Have asked my solar guy as well but waiting to hear back from him.

Thank you.

My roof

[mgalaxy3]

No worries thanks for sharing info, it was an issue in wiring seems like the installer was a newbie.

[umans]

look for unistrut channels

[sardarg]

sir @AkbarGr8 you my seek help from any shop dealing in aluminum windows & door frame fabrication. they can provide you such strut channels. very convenient but tricky installation for slopped slab.

[AkbarGr8]

Selling my solarmax hybrid inverter, please reach out if interested.

https://www.olx.com.pk/item/solarmax-6kw-pv6000-excellent-condition-for-sale-iid-1091949458

[mrdeejay]

Whats the current lesco off-peak unit rate including taxes?

[mgalaxy3]

What do you folks think about off grid setups? Reducing as much reliance on WAPDA as possible.

I understand net metering can give 0 bills but suppose someone wants to remove their dependence on power company to most extent if not 100%. Or suppose grid is not available in the area at all.

With LFP battery prices coming down, it seems like a possibility. 4.8kwh around 200k.

EG a house uses 800 units a month, 26 a day.

What size LFP battery bank can reduce WAPDA reliance by 90%? Will 38kwh suffice?

PV will charge bank in day time. Extended rainy days may be troublesome.

[noobie]

Yes, 38 kWh will be sufficient, as the Depth of Discharge (DoD) typically ranges from 80% to 90% for LFP batteries. Assuming 80% DOD, you would have approximately 30 units available per day but you'll need to calculate the solar system capacity to ensure it can charge the battery during the day while simultaneously powering your loads. I think the major issue is density at the moment. 38Kwh means you'll need at least 8 batteries (most batteries in market are of of 4.8KWH/5KWH). I know LFP is safe but i just don't feel comfortable because its impossible to extinguisher lithium batteries fire.