Generator vs backup battery price comparison

[jetlee]

You'd be surprised, we've had our next door neighbour run his for 12 hours, due to a massive outage his side had. My little one ran for 10 hours when my sons dojo was using it.

fair enough, **** happens. Im just trying to keep the debate on track. Did you not have to refuel in 10 hours ?

 

[Lupus]

fair enough, **** happens. Im just trying to keep the debate on track. Did you not have to refuel in 10 hours ?

Depends on the load used, but there was still about 2 or 3l left after they used it for that long, that 2 or 3l was used for 2 4 hour sessions afterwards.

 

[A3@MBB]

Not using a generator for long periods is also an issue, and not mentioned in the article is the air pollution aspects that need to be looked at, as these exhausts do not have catalytic converters and the sophistication that some cars have. Heaven knows what all the diesel generators across a city spew out when load shedding starts as well... Batteries are pretty costly yes, but working well for me for last 3 years, and I suppose the added advantage is, I'm using a good 7 or so hours of stored sunshine every evening, so that adds up over time to help offset that cost.

And you think the manufacturing process of said batteries are only producing fairy farts?

 

[A3@MBB]

Double door 600l fridge freezer combo on average 30 to 40w, when compressor kicks in 270w

Wow, that's quite low.
I'm busy with my own pre-solar install needs analysis and I've recorded inrush currents as high as 1354W.
Average draw is about 60-65W.
These are newish Bosch units (individual fridge & freezer)

 

[Lupus]

Wow, that's quite low.
I'm busy with my own pre-solar install needs analysis and I've recorded inrush currents as high as 1354W.
Average draw is about 60-65W.
These are newish Bosch units (individual fridge & freezer)

I was surprised as well, I was expecting it to be higher. But it is a A++ fridge

 

[PsyWulf]

Thats not entirely accurate. You wont require all the storage at once in the same way I doubt that genny will run flat out for 7 hours ..

Even though I have run for 12 hours at a time i'll bite since this is getting entertaining

Please quote for 2x4 hour sessions in a day 5kw/h, assume you can recharge your 20kwh 100% dod battery inbetween

I'll wait *again*

 

[jetlee]

Wow, that's quite low.
I'm busy with my own pre-solar install needs analysis and I've recorded inrush currents as high as 1354W.
Average draw is about 60-65W.
These are newish Bosch units (individual fridge & freezer)

At night all thats running for me is a split door fridge freezer, a 12v camping fridge for beer, a 4 "servers" at about 10w tdp each, some switches, about 5 or 6 led lights (inside and outside), 2 IP Cameras, alarm and and I never see my total draw go over 300w (while Im sleeping) ..

fridges have gotten pretty good

 

[PsyWulf]

Caveat: I have both,i'm not trying to say Inverters have no place. But the inverter-messiahnists need to calm their tits

 

[Lupus]

Caveat: I have both,i'm not trying to say Inverters have no place. But the inverter-messiahnists need to calm their tits

Unless their connected to a solar system charging them up at night, then they do push ahead over the generator.

 

[jetlee]

Even though I have run for 12 hours at a time i'll bite since this is getting entertaining

Please quote for 2x4 hour sessions in a day 5kw/h, assume you can recharge your 20kwh 100% dod battery inbetween

I'll wait *again*

Hope you not waiting for me, I'm not trying to imply you can run that kind of load in the real world, I was merely pointing out that in your example, you are stretching with 7 hour loadshedding slots (even with 4).. My use case is more real world. I use panels and batteries and I dont try to stretch for 20kwh at a time, because its not practical.

I am trying to compare a real world 2kwh - 3kwh load requirement during a load shed, which is what this article was meant to be about ... and the cost of fuel relative to the actual cost of the equipment.

 

[bwana]

Comparatively, battery backup systems require a larger up-front investment but have don’t any additional running costs.

What about charging them?

 

[Lupus]

What about charging them?

Sun? 300 hamsters on wheels? Batteries don't car

 

[bwana]

Sun? 300 hamsters on wheels? Batteries don't car

People with solar panels probably don't care about backup power during loadshedding and 300 hamsters are expensive to keep. The point is if you use it you have to charge it and, just like petrol, that costs money for people living on the grid.

 

[Lupus]

People with solar panels probably don't care about backup power during loadshedding and 300 hamsters are expensive to keep.

About 60 bucks each so 18k, though you do need to feed them and clean up.

 

[A3@MBB]

At night all thats running for me is a split door fridge freezer, a 12v camping fridge for beer, a 4 "servers" at about 10w tdp each, some switches, about 5 or 6 led lights (inside and outside), 2 IP Cameras, alarm and and I never see my total draw go over 300w (while Im sleeping) ..

fridges have gotten pretty good

Yes, my night usage should be quite similar.
The peak of 1.3kW is maybe a fraction of a second.

I'm tossing between a 5 or 8kw Sunsynk, hence doing the analysis

 

[jetlee]

Yes, my night usage should be quite similar.
The peak of 1.3kW is maybe a fraction of a second.

I'm tossing between a 5 or 8kw Sunsynk, hence doing the analysis

I see that looks like a pm smart switch monitoring .. I only mostly measure at the inverter and only my big power users on smart switches .. so I suppose that could be happening and I'm not noticing ..

 

[PsyWulf]

Unless their connected to a solar system charging them up at night, then they do push ahead over the generator.

On cost too,thats the point

Unlimited budget can out-engineer everything

 

[Lupus]

On cost too,thats the point

Unlimited budget can out-engineer everything

You could build a ladder to the moon

 

[zeb]

Alright now we're getting somewhere
If we can't adjust any usage on generator we can't do the same for inverter - please quote the cost of a 5kw generator running at 7hours full tilt ,vs 35kwh battery storage backup system for 7hours at 5kw

I'll wait

No we're not. I never argued that price wise you can get the same value and I'm not arguing in favour of either option.
My point is you need a proper generator to run a whole house. A generator between R50k and R100k will run everything a R300k+ solar system will.

I have used a diesel generator from around 2008. Never regretted buying it and I won't get rid of it, even though I have installed a proper solar system.

 

[rh1]

So you'd be one of those that fires up the generator as soon as the power goes out then? I always find it comical how many people do that.

I only tend to use the genny on a Saturday mornings when we do the laundry, so we can run the pumps that supply the water to the washing machine and the washing machine itself.

Otherwise I dont use it.

Edit: only during loadsheddings.