What happens when solar power is cheaper than grid power? - Page 2

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Re: What happens when solar power is cheaper than grid power?
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http://jaycar.com.au/productView.asp?ID3D%SB1695&form3D%CAT2&SUBCATID3D%997 =
#12
$305
12V 100AH DEEP CYCLE GEL BATTERY
Deep-cycle gel performance for solar installations


http://www.jaycar.com.au/productView.asp?ID3D%ZM9088
$659
200W Powertech Monocrystalline Solar Panel


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$1400   (from $350 for 1500W)
2000W Sine Wave Inverter Charger
Combining the functions of a pure sine wave inverter, battery charger
and automatic transfer switch in one unit


BACKUP!
Hardly a noise if you dig a small ditch.
http://www.jaycar.com.au/productView.asp?ID3D%MG4502
$899
2kW Sine Wave Inverter Generator


*******

Demo setup in hot city..

900W airconditioner.

5 hours direct sunlight run during day
+ 5 hour run at night
3D% 1800W Solar Panels

200W 3D% $650
2000W 3D% $6500

5 hours charge at 1000W
/10V 3D% 100AMP

5 100AH batteries 3D% $3000

That's an AIRCONDITIONER 10 hours a day.

If you can get away with fans or evap. cooling you could power 5
houses with that setup!

If you only power the aircon during peak sun, only 1/3 that price.

I'm setting up a $3000 - $4000 setup this month just to run a 400W
halogen heater, microwave etc.

I just used my printer for an hour with a $50 inverter and the $500
panels and batteries setup I have now.

Herc

Re: What happens when solar power is cheaper than grid power?

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And how much will you end up running it? Quite a lot in practice, and it
requires an oil change very 20 hours. It's not designed to be used
semi-continuously. The petrol costs will be significant.

Sylvia.

Re: What happens when solar power is cheaper than grid power?
[]
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It's the bleeding obvious:)

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True. True is also that the present economy is a false one. The
environmental damage is not priced in yet. Even with the carbon tax.
We are using a technology that is almost 150 years old, because it is
cheap and convenient. Shift the goal posts and you will be amazed how
quickly new, and possibly even cheaper technologies will emerge.
Example:
http://web.mit.edu/newsoffice/2011/flow-batteries-0606.html
Sometimes we need political power to overcome the power of the capital,
to push the cart in a different direction. It's been dragging on for too
long. Would you have imagined 20 years ago that so soon we will have
1000 Gbyte hard disks in a laptop?

Tony




Re: What happens when solar power is cheaper than grid power?

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Way to shoot yorself in the foot. If there is one battery that would
illustrate your point, it is the basic lead acid battery as in the
standard car battery, or even derivative, aka the deep discharge lead
acid battery as used in power systems. cost of them is still a major
sticking point.


Re: What happens when solar power is cheaper than grid power?
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It's the REPLACEMENT COST of the batteries.

http://jaycar.com.au/productView.asp?ID3D%SB1695&form3D%CAT2&SUBCATID3D%997 =
#12

12V 100Ah Deep Cycle Gel Battery
$305

This will deliver 1200W for 1 hour.

But if you fully charge and fully discharge every day..

3 month 3D% 91%
6 months 3D% 82%
12 months 3D% 64%

so it loses 9% every 90 days.

But if you don't run AIRCON and ELECTRIC OVENS

you can effectively trickle charge them.

i.e. have way more batteries than panels.

you can supply a good SURGE POWER - i.e. microwaves, pressure
cleaners..
and keep the batteries charged for 1-2 weeks of cloud cover,
but your total power usage must be kept down.

then you get triple benefit
by batteries only charging / discharging 10% capacity each day

1 long battery life in decades
2 batteries always topped up over 2 weeks cloud cover
3 high surge power when needed

Herc

Re: What happens when solar power is cheaper than grid power?
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The cost of capital gets you then. All that money tied up in batteries
that could be earning interest in a bank account or and capital gains
and dividends invested in shares.

Sylvial




Re: What happens when solar power is cheaper than grid power?
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997#12
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5% interest X $10K 3D% $500/year

WOW!  I make that in 1 hour

We're not talking about you below the mean bludgers and pastry chefs.

Anyone living above the mean can fork out $5K for no-aircon,
$10K for air-con solar setup anywhere north of Tasmania.

You can run an aircon during sunlight for basically free.

You can't rationalise changing from a centralised power setup
to a intra-power setup using all the same paramters.

You have to work with the technology.  You've have to ween yourself
off 3KW ovens roasting chickens for 3 hours.

You have to schedule the aircon run times.

You have to use a gas oven.

You have to use LED LIGHTS for a small setup.

You have to charge your battery if you go independant after a week of
cloud.

Although AMORPHOUS PANELS are supposed to work better in cloud.

Not that much dearer, but take 3 times the space on your roof.

Herc

Re: What happens when solar power is cheaper than grid power?
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Why are they magically cheaper when you replace them?

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Very expensive.

Definitely not unless you want to explode the battery. That rating is at
best 60watts for five hours. Any more or longer and the life cycles head
south.
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Then you are definitely fscking it.




Re: What happens when solar power is cheaper than grid power?
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997#12
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that's only 5AMP!  wouldn't even get warm!



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you still have 64% capacity after 1 year, that's with full 365 charge/
discharge cycles.

This isn't my suggested usage, quite the opposite.

check the link there is a data pdf file which I quoted part of.

including the 1 hour discharge capacity.

Herc

Re: What happens when solar power is cheaper than grid power?

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Not if you ever fully discharge them or discharge Gel at a rate >
C(amphour capacity)/20.

Re: What happens when solar power is cheaper than grid power?
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No you idiot!  that IS the rating given.  full discharge over 24 hours
X 365

actually its probably 12hrs up and 12hrs down.

I quoted 1 hour to convert from AH to Watts, then used far less than
1/20 (2 weeks) in my post.

Herc

Re: What happens when solar power is cheaper than grid power?

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Which automatically reduces the effective capacity.
Hint, go read the fine print. Advertised capacity is rated over 20 hours.

Hint, look at tables for solar insolation/isolation. The sun doesn't
shine effectively for 12 hours. In fact, search for effective sun hours.


Re: What happens when solar power is cheaper than grid power?
On Sat, 07 Jul 2012 14:37:20 +1000, the following appeared
in sci.skeptic, posted by terryc

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I live in Arizona, in the desert. Our nominally 6.45kW solar
photovoltaic system faces south (optimum for the US) and
usually generates a net peak of approximately 5.6-5.8kW, at
solar noon, during May when the combination of sun angle and
temperature provides the best results. The total power
generated on average in May is approximately 42kWh/day, or
less than 2kWh/h averaged over 24 hours. And although this
could be improved with the addition of solar tracking panels
(a rather expensive custom proposition for residential use),
at best it could provide around 60-70kWh/day.

And like all home photovoltaic systems I know of, it
supplies zero if grid power is lost, since the inverter has
no internal frequency generator and is required to "lock" to
the incoming line frequency in order to function.
--

Bob C.

"Evidence confirming an observation is
We've slightly trimmed the long signature. Click to see the full one.
Re: What happens when solar power is cheaper than grid power?
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SHORT ANSWER:  lots of batteries cost more than 1 battery

LONG ANSWER:

No, the initial battery cost is small.

2KW 24/7  (all sunny days)

$300 3D% 100AH 3D% 1200WH 3D% 1000W effective for 1 hour

2 batteries 3D% 2KW x 1 hour
50 batteries 3D% 2KW x 24 hours

STARTUP COST
$15,000 battery to run a big aircon all year 24/7

REPLACEMENT COST
$150,000 batteries to maintain system for 10 years.

(battery only lasts a year full charge/discharge every day)

You can get longer life, say 5yrs  (and maintain charge during a weeks
cloud)
if you started up with $50,000 batteries.

Mind you that will run a big aircon full time for 5 years, through
cloudy weeks.

Townsville / Cairns setup where 95% of houses run aircons all day,
nearly all year.

Herc

Re: What happens when solar power is cheaper than grid power?
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So basically if you need aircon during the night and there's a grid
handy, use the grid!

that's why I'm experimenting putting 40W peltier cooling elements in
my 40W evap cooler!

You know how in stores they put ice in the demo evaporative coolers
and they work really well?

A small peltier device (12V esky component - $15 from Jaycar)

will keep the tank at 5 degrees, no ice needed!

they don't make coolers like that because it takes 30min to cool the
tank which catalyses the evap cooling effect.

Herc

Re: What happens when solar power is cheaper than grid power?
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Peltier devices are hoplessly inefficient.



Re: What happens when solar power is cheaper than grid power?
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NO they are not.

But all the 12V Eskies don't hook them up properly.

You put a liter of water on the metal part inside the esky, tilt it
slightly
and you can cool a bottle of coke quicker than your fridge.

They need a thermal inertia contact, don't work much just cooling the
air like the $50 car eskies.

Ideal for a Evap cooler water tank (but partition the tank into a
smaller section with the peltier and cloth) so it cools a lot quicker.

Herc



Re: What happens when solar power is cheaper than grid power?
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The current required as you scale up to that level of cooling is what I'm
talking about.




Re: What happens when solar power is cheaper than grid power?
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You just need better insulation.

In winter I get 8-9 days with ice in my esky by putting it inside a
$20 plastic crate on a foam mat.

Peltier coolers are pretty good, the lowest 12V compressor fridge
takes 2AM continuous.

You can cool quickly with a peltier with 5amp-10amp
then reduce it to 1amp or so for continuous use or use a thermostat.

The 12V peltier eskies are so bad they never bothered to install
thermostats.

I'm making a cool room with conventional electric oil heaters in them
working in reverse, having a cooling element on the top of the
radiator that cycles the cold water inside the radiator, absorbing
heat in the room and fanning it outside via the peltier heat pump

*
*  WALL
*
*
|| |3D%3D3D%|
*  |  |   |     cool room with peltier radiator (heater filled with
water)
*  |3D%3D3D%|
*  ^     ^
3D%3D3D%3D3D%3D3D%3D3D%3D3D%3D3D%3D3D%


power up a peltier device and touch it!  they are instantly cold as
the inside of your freezer!

Herc

Re: What happens when solar power is cheaper than grid power?
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