Cost of generator produced electricity

Mike Harding · Guru

Cost of generator produced electricity

bobsa · Senior Member

SA price
origin
40.42 c per kwh for the first 4 kwh, then 43.16 per kwh , plus 91.25 c per day supply charge,
the genny is not that far away
you do get discounts for direct debit and online bills
dont even get me started on gas supply charge and cost got mine disconnect and went 9kg swap and go
cost me a lot less , but i only got a stove on gas about a 8.5 kg per 3mths if I am at home
bob

Desert Dweller · Guru

Interesting, we've never felt the need to buy a generator.

Our basic non attached 120W solar panels have served us well over the past 6 years.

LED lighting, camera/phone top ups & TV/DVD viewing.

What more do you need?

Clean, green & our neighbors have no reason to complain.

Best of all it costs nothing except for our initial outlay on the panels which were way cheaper than buying a generator.

A no brainer really.

-- Edited by Desert Dweller on Tuesday 29th of May 2018 07:07:01 PM

Mike Harding · Guru

bobsa: Fair enough, I did quote only the kWh price and not the supply charge but I've dug out my bill for the last summer quarter and divided the bill total by the number of kWh and it works out at 36c per kWh and, obviously, the summer bill would have the highest kWh charge when calculated in this manner, so the gen is still over twice as much.

DD: Solar panels won't support a 12V fridge/freezer in Victoria and Tas for most of the year.

Peter_n_Margaret · Guru

Mike Harding wrote:
DD: Solar panels won't support a 12V fridge/freezer in Victoria and Tas for most of the year.

That is not our experience.

The fact is that solar performs better in cold conditions and in colder conditions the power requirements of the fridge/freezer are lower any how.

Cheers,

Peter

mezza56 · Senior Member

Now thats arguing over tin tacs guys who gives a sh.... if its 30c or $1.30 , I hardly use my generator , but its sure handy to run the air con on a stinker.

rockylizard · Guru

Gday...

P-n-M and Mezza - I agree.

Cheers - John

iana · Guru

Went into this during the early days on the forum. During the winter months, the sun is low on the horizon, so the panels need to be tilted to say in Perth 57' to get their efficiency. If you look at all static panels they are tilted by varying degrees depending on latitude. In the summer flat mounted panels are OK. So this is the reason why during the winter months your panels do not produce enough power.

Mike Harding · Guru

>So this is the reason why during the winter months your panels do
>not produce enough power.

It's a small part of it.

The major reasons are that the sun is lower in the sky so the hours
of sun are fewer and this worsens with increasing latitude. Also the
low angle of the sun means its radiation has to travel a greater
distance through the earth's atmosphere thus being more attenuated
than when the sun is higher in the sky.

NB. The forecast for Ouyen in north western Victoria does not even
recommend sun protection for humans at this time of year:
http://www.bom.gov.au/vic/forecasts/ouyen.shtml
There simply is not enough energy reaching the ground to require it.

I was camped in the forest on the bank of the Murray, not too far
from Ouyen, for a week about one month ago and I didn't even bother
setting up my solar panels. The very short useful energy period from
the sun combined with the shade of the trees meant I would have
collected 5Ah to 10Ah from my 180W of panels and MPPT controller - if
I was lucky - nowhere near enough to support my 12V fridge/freezer
which consumes about 25Ah per day at this time of year.

The worst I have had from my set up was 2Ah on a wet and overcast day
last year. Hence why I say solar will not support a fridge/freezer
year round in Vic/Tas.

blaze · Guru

Mike Harding wrote:
>So this is the reason why during the winter months your panels do
>not produce enough power.

It's a small part of it.

The major reasons are that the sun is lower in the sky so the hours
of sun are fewer and this worsens with increasing latitude. Also the
low angle of the sun means its radiation has to travel a greater
distance through the earth's atmosphere thus being more attenuated
than when the sun is higher in the sky.

NB. The forecast for Ouyen in north western Victoria does not even
recommend sun protection for humans at this time of year:
http://www.bom.gov.au/vic/forecasts/ouyen.shtml
There simply is not enough energy reaching the ground to require it.

I was camped in the forest on the bank of the Murray, not too far
from Ouyen, for a week about one month ago and I didn't even bother
setting up my solar panels. The very short useful energy period from
the sun combined with the shade of the trees meant I would have
collected 5Ah to 10Ah from my 180W of panels and MPPT controller - if
I was lucky - nowhere near enough to support my 12V fridge/freezer
which consumes about 25Ah per day at this time of year.

The worst I have had from my set up was 2Ah on a wet and overcast day
last year. Hence why I say solar will not support a fridge/freezer
year round in Vic/Tas.

My first hand experience is solar does ok in tassie, even in winter. You may need an extra panel. My batteries are normally charged by lunch time each day. I have 320w of panels and 2x100 amp/h batteries

cheers

blaze

Eaglemax · Guru

Good topic.

Thanks Mike for your findings. It is interesting the basic costs of running a genny.

I'm planning to build my next van. The small one I built has 100amp AGM, 120W solar on the roof and 90W mobile. We can last around 3-4 days then the battery starts going flat. I installed a redarc solenoid but I've learned that it isn't a great answer to running the AGM flat, just takes a little longer to do so.

I've read up so much on this problem. My Kipor 2KW genny at home is too heavy for our lightweight van to take and our vintage car hasn't got the room unless we leave our foxy at home- no way. I read recently that rather than a solenoid it is better to run say a 400W inverter from the car battery to a smart charger (I have a 12amp one) while you are driving. That will ensure the AGM is fully charged on arrival. Then it will trickle charge for some time and the inverter will cut out at 10 volts enough to start the car (I hope, haven't tested that yet). If not I'll think of a way to cut out at 11 volts, help from the AGM.

That's a little off topic. I read that the Yamaha 1000W genny is only 12kg so that's an option for some. If my wife left her handbag at home?...

Mike Harding · Guru

Blaze:
How much energy are you using/charging per day? And, yes, of course
if one has enough solar panels just about anything can be done but
I'm already carrying 3 x 60W and don't want more.

----

Eaglemax:
Have a look at this gen. I was very tempted some time ago when they
first appeared on e-bay by their low weight and small size and I note
Dick Smith are now selling them, and with a good warranty, so they
may be OK - ignore the 2kW and 1.2kW claims - I'd reckon they are
probably good for 800W to 1000W continuous but that is more than
enough for battery charging:

https://www.ebay.com.au/itm/Baumr-AG-2-000W-Petrol-Inverter-Generator-BM-X20i/192548529276?epid=1342408526&hash=item2cd4c9647c:g:JGMAAOSwqYZbBZtr

There is merit in the inverter/smart charger system in the vehicle.
If you drive for long enough it will do a better job of charging the
AGM than the vehicle system but it's all a bit messy and, in reality,
it'll probably only give you an extra 10% or 15% of charge - which
may well be worth having?

As I've started to look more closely at power budgets for permanent
living in a caravan in free camps I begin to realise how mcuh power I
could easily use and how difficult that will be to replace in a
Victorian winter, as you say, an interesting area.

Peter_n_Margaret · Guru

In summer at higher latitudes, the sun is at a lower angle, but the days are longer too.
The extreme of this that we have encountered was at North Cape in Norway which is at 71°1021N and is the furthers most northerly place that you can drive to in the world.
In mid summer, the sun does not set, but is always less than 45 degrees above the horizon.
We were still getting 300mA charge from our FLAT panels at midnight, and of course, much more than that for most of the 24 hour day.
We had a compressor fridge and never looked like having a power shortage anywhere in Europe.

Harder in the winter of course, but then you could just leave the fridge turned off and it would stay cold..... biggrin

Cheers,

Peter

Aus-Kiwi · Guru

Letâs compare camping ground prices to generator ? To me you use whatever you want .As long as it doesnât interfere with anything else . The price of gas may need to be included too..Depends if home has elect hot water ? Itâs not just the price ? But usage also . A generator may only need to run 20min a day ?

Onedodger · Guru

mezza56 wrote:
Now thats arguing over tin tacs guys who gives a sh.... if its 30c or $1.30 , I hardly use my generator , but its sure handy to run the air con on a stinker.

X2

Aus-Kiwi · Guru

X3 ..

blaze · Guru

Mike Harding wrote:
Blaze:
How much energy are you using/charging per day? And, yes, of course
if one has enough solar panels just about anything can be done but
I'm already carrying 3 x 60W and don't want more.

----

Eaglemax:
Have a look at this gen. I was very tempted some time ago when they
first appeared on e-bay by their low weight and small size and I note
Dick Smith are now selling them, and with a good warranty, so they
may be OK - ignore the 2kW and 1.2kW claims - I'd reckon they are
probably good for 800W to 1000W continuous but that is more than
enough for battery charging:

https://www.ebay.com.au/itm/Baumr-AG-2-000W-Petrol-Inverter-Generator-BM-X20i/192548529276?epid=1342408526&hash=item2cd4c9647c:g:JGMAAOSwqYZbBZtr

There is merit in the inverter/smart charger system in the vehicle.
If you drive for long enough it will do a better job of charging the
AGM than the vehicle system but it's all a bit messy and, in reality,
it'll probably only give you an extra 10% or 15% of charge - which
may well be worth having?

As I've started to look more closely at power budgets for permanent
living in a caravan in free camps I begin to realise how mcuh power I
could easily use and how difficult that will be to replace in a
Victorian winter, as you say, an interesting area.

Hi Mike

I got a 4kva gennie too

don't take it all the time but if I have a need I do

cheers

blaze

Bagmaker · Senior Member

not much sense running a generator to top up batteries. They wont accept any amperage in the final fill stage. Better to start the day with generator and top up with solar or not at all

Mike Harding · Guru

Bagmaker wrote:
not much sense running a generator to top up batteries. They wont accept any amperage in the final fill stage. Better to start the day with generator and top up with solar [snip]

Excellent advice.

blaze · Guru

Bagmaker wrote:
not much sense running a generator to top up batteries. They wont accept any amperage in the final fill stage. Better to start the day with generator and top up with solar or not at all

I don't think many would charge from the gennie, most would some sort of charger, a 30 amp smart charger would do the job fine

cheers

blaze

Mike Harding · Guru

blaze wrote:
Bagmaker wrote:
not much sense running a generator to top up batteries. They wont accept any amperage in the final fill stage. Better to start the day with generator and top up with solar or not at all
I don't think many would charge from the gennie, most would some sort of charger, a 30 amp smart charger would do the job fine

Bagmaker wasn't referring to people charging the battery from the 12V generator output.

And a "smart" (or not so smart) charger is not the answer when it's running from a generator - it can fully charge the battery but it's a bad way to do it.

The majority of charge is produced during the early and middle phase of charging, the final stage forces comparatively little charge into the battery but takes a long time because the battery's internal impedance has now risen considerably so although you can continue to charge from the generator it will take probably as long as it did to do the early stages.

A much better way is to do, say, 75% of the charge from the generator and then use solar panels to produce the remainder. So run your generator from say 9am to 11am and then switch to solar panels.

btw: A *30A* charger should be used with care: the maximum specified charge for my Powersonic 100Ah AGM battery is 27A.