Hello from Africa

[J.P.M.]

That's a fine example of the snarkiness endemic on this forum
that one has to endure. It's worth it, but you do have to develop a
thick skin. Normally I just ignore it, but since we're trying to
welcome a newbie here, I figured it's worth pointing out.

As long as you're getting picky about stuff, why not get your the respectful and known conventions about capitalization of units correct as in kWh vs. kwh etc. correct. That you make those errors in a post critical about being picky seems more than a bit ironic.

[russ]

That's a fine example of the snarkiness endemic on this forum
that one has to endure. It's worth it, but you do have to develop a
thick skin. Normally I just ignore it, but since we're trying to
welcome a newbie here, I figured it's worth pointing out.

No one has ever told you it isn't nice to whine?

[DanKegel]

I wasn't being picky; I was being welcoming.

Exact spelling isn't my forte. I'm lucky if what I write is legible. (Especially today - my right arm is in a cast!)

[J.P.M.]

I wasn't being picky; I was being welcoming.

Exact spelling isn't my forte. I'm lucky if what I write is legible. (Especially today - my right arm is in a cast!)

I'm lucky if what I write makes any sense most of the time, much less being legible, particularly just now. My left one's in a sling. Between that and the pain killers, I can't even close my eyes and use it to pretend it's a stranger.

[DanKegel]

I have a prescription for vicodiin, am resisting filling it

[Legit]

I have a prescription for vicodiin, am resisting filling it

Plse don't be concerned about how oaks reply, the knowledge imparted is important and what's appreciated - thks for your concern and the welcome which is also much appreciated.

Apologies, 10,000w/hrs p/day is correct, and the gizmo is a Efergy Energy Monitoring Socket.

The plan is to go off the grid, so energy storage will be a major cost, will certainly look at ways to reduce and save on energy usage

[DanKegel]

10,000w/hrs p/day is correct...
The plan is to go off the grid, so energy storage will be a major cost, will certainly look at ways to reduce and save on energy usage

The Bosch unit looks pretty real, so as a thought experiment, let's say you go for the smallest Bosch unit, a 4.4 kwh battery with integrated 5kw solar inverter, and spring for the 15 year warranty.
Its usable storage capacity starts out at 2.2 kwh and degrades to ~1.5 kwh at end of ~15 years, I think.
Will 1.5kwh get you through the night?
Even if you go for the 8.8 kwh model, will ~3kwh get you through the night?

[Legit]

Let's say after cutting back on usage ect. we end up using 5,000 w/hrs p/day, we have lots of sun but will need a battery back-up that will last for 2 x full overcast days, so need to store 10,000w/hrs from the batteries, if you agree, then we need a system to handle this - have heard of the Bosch system, sounds good.

[Legit]

Question to see if am on the right track :

We use 5,000wh p/day and need a system to handle 2 x overcast days, 5,000 x 2 = 10,000wh.
The watts used p/day according to the specs on the appliances is 1,000w, we double that to 2,000w for the peak surge or start up surge(will use less than 2000w as there is no fridge,power tools,microwave ect.)


1. The Smaller Bosch 2,2kwh - 1,5kwh with 4,4kwh battery storage capacity should do the job for 21,12hrs depending on the
type of batteries used, am assuming they have taken into account the % that must be left in the batteries when giving the systems battery capacity.
2. To get to the required 2 days of power on the overcast days,could one still use the above smaller Bosch 2,2kwh setup
and just add more batteries until you get to the required 10,000wh?

Thanks in advance

[DanKegel]

A system with 1.5khw usable capacity can power a 5000 wh/day load for 1.5/5 = 0.3 days = about 7 hours.

No, you can't add batteries to the Bosch system. If you want 48 hours of backup, you'd need 10kwh / 50% dod / 70% eol capacity = a 28 kWh Bosch system. The biggest one they sell is 13.2 kWh, so you probably don't want to do that.

(Take my figures with a grain of salt, I'm no expert.)

I think the Bosch system is meant for people with a reliable grid connection but no net metering or feed-in tariff. It's (theoretically) about saving money, not about going off grid.

If you want to go off grid with today's technology, you may need to take an axe to your energy usage. Probably means lifestyle changes or tons of money.

[Legit]

Ok thanks for your patience, time and info DanKegel, the Bosch system is out of the window, in our society, people are either the Have's or Have Not's and are taxed accordingly, the Have Not's account for a very large portion of our national electricity usage and pay very little or do not pay at all for usage, so guess who pays - this is a major reason why users are gravitating towards being self sufficient - our Government who control the power grid is not in favour of the grid-tie in system as they stand to loose revenue from the few paying customers.

So with this in mind i will still be doing a costing into going off the grid - you may get a glimpse of the importance, cost wise, the battery side of the system plays - I will tomorrow get hold of one of the tried and tested solar outfits "Victron" have a outlet in SA, and get a costing on the cost of a off-grid system system to handle the above.

Am thinking of also posting a question to Sunking and others for advise on the type of batteries to use for a off-grid system

[DanKegel]

Yeah, http://www.victronenergy.com/upload/...ems_EN_web.pdf
looks like they're more up your alley. They sell a nice 4.8 kwh battery
( http://www.victronenergy.com/upload/...ynx-ion-EN.pdf )
rated at 2000 cycles to 80% dod and 0.3C discharge rate. Not as long-lived as
the Bosch one (and I don't see any warrany info), but it's boots on the ground, and Victron is much more
attuned to your use case.

But even Victron recommends a genset as backup. If you used one of those
on cloudy days, you might get by with the smallest of Bosch systems.

So be careful to compare apples to apples, and beware glossy sales brochures!

[Legit]

Thanks, will keep u up to speed

[SunEagle]

A system with 1.5khw usable capacity can power a 5000 wh/day load for 1.5/5 = 0.3 days = about 7 hours.

No, you can't add batteries to the Bosch system. If you want 48 hours of backup, you'd need 10kwh / 50% dod / 70% eol capacity = a 28 kWh Bosch system. The biggest one they sell is 13.2 kWh, so you probably don't want to do that.

(Take my figures with a grain of salt, I'm no expert.)

I think the Bosch system is meant for people with a reliable grid connection but no net metering or feed-in tariff. It's (theoretically) about saving money, not about going off grid.

If you want to go off grid with today's technology, you may need to take an axe to your energy usage. Probably means lifestyle changes or tons of money.

Every smart person that goes off grid has an emergency generator in their tool box. The batteries will only last just so long and the cost to double their life is crazy high. So you back up the batteries with that gen set which is also used to perform an EQ charge every once an a while.

[Legit]

Hmmm!! this is going to take longer than expected, the Victron boys would like very specific energy usage due to the high cost of the system - so going to take longer than expected