After some investigation, I've decided to CONSIDER a completely different
approach to a petrol, or diesel generator. I can buy a 3kVA inverter for
about $3k and some Solar cells (10 X 115Watt panels) for another $8k. The
gummint gives me back $4k (yay!). I have plenty of easily accessible (
Only if your inverter is the appropriate type. Not sure if the price you
mention for 3kVA is for a stand-alone or mains-connectable.
The batteries sound cheap. Mine are 700AH, 24V and cost $4000 new. The
rebate also has conditions - e.g. the system must use NEW components (I
think) and be installed by an accredited installer etc.
There is no replacement for a generator. Every decent set-up still needs
Pure sine wave inverter/charger approved for grid interactive connection
for $3K? Sounds too good....
Fair price...but for the system to operate without recharge from mains or
diesel generator, you would need a lots of modules. Do not forget, 115 watts
is peak power. You can count on 1/2 average per day. 5 modules (24V) would
average 600W. You would need much much more than that.
It is if you meet conditions. There are plenty....
The most important part of the system is, guess what, the battery bank!
While everything else can be second hand and still work, there is no such a
thing as "refurbished second hand" stationary battery that still have enough
capacity for the system.
The proper term would be double Whammy. Kilowatt produced by the system
would cost at least 3 times more than from the mains. If approved, power
authority will pay you fraction for what they charge.......
No neighbour problems and get to have a warm, fuzzy, green
The hybrid power generation is hijacked by the global oil corporations.
Basically, there are no real investments or R&D.
They are waiting for oil to run out or when pollution is prohibitive to use
Therefore, cost of the components is just too high. We can only dream to see
solar panels on every roof in Australia.
There are thousands of panels along German highways, but not many here....
Do the maths better....
**$4.5k for the mains-connectable type. **Batteries are second hand.
**I figure on leaving the batteries out of the system, then installing them
later, just unsing mains interactive inverter. The acredited installer part
should not be a problem (I hope).
**Bugger. **Yeah, sorry 'bout that. $4.5k for mains interactive. **I plan on using 10 modules. Maybe adding a wind generator (200W), if I can
slide it past the council and neighbour objections. **So I've found. **My battery guy has a fair bit of experience in this area. **Typical. **I'm pretty certain I already have.
Silicon manufacture for solar cells requires more
energy than the cells can make in thirty years, that
doesn't count the energy to process the silicon into
solar cells or the losses to store the energy made
If you look closely at the manufacturer's specs
you'll see the power drops off to about 80% after
ten years, due to micro fractures in the silicon
material causing performance degradation and a life
of about 20 years.
You'll most likely be doing the environment a favour
by buying an alternator instead and just using it
when neccessary. With proper maintenance and storage
it probably will last longer than the cells anyway
and definitely longer than the batteries you'll need.
The added advantage would be that it's compact,
cheaper, higher in output and needs less space than
a solar installation would.
"Trevor Wilson" ** You need to broaden you horizons - Trevor.
If your power goes off - then so does the whole area.
There is an *opportunity* here.
Get a 20 kVA diesel gene and some long extensions, so you can supply power
to your immediate neighbours.
10 neighbours at say $50 a day could be quite lucrative.
Charge that pesky Leb next door double too.
Solar really only adds up economically when you're in the middle of
nowhere and have to generate your own power. Mains power is actually
really good value when compared to trying to generate it yourself.
Power 24/7 aint cheap to do.
If you want backup, have a look at second hand places, machine yards,
auctions etc. A quality second hand genset is better than a $100 pile
of shit from bunnings. I got a 3kVA online UPS at an auction not long
ago for $20, batteries were stuffed but after getting some new
batteries I had a 3kVA online unit for the same price as a 400VA
standby unit. Actually if you get an Active online type UPS you could
pretty much use any generator you liked as they rectify all the
incoming mains and invert it again.
Seriously, My house would run comfortably on < 1 kw/hr (not counting
I have compact fluros everywere, with only 2 - 3 on at one time, The TV
when used and computer,
Cooking / washing is done by natural gas. My last power bill was a
miniscule $70 for the last 90 days that, i belive is bloddy good.
we have 1 fridge and 1 chest freezer that run when needed. I dont use
heaters much if at all, the heat generated during cooking is enough to
provide the evenings heat.
if i were to switch most items to 12V (lights etc) i could run
alternative energy sources. why 12(24) up convert to 240 for lighting
when you can jsut use cheap and power friendly CCFL's? LCD monitors run
internaly from 12v (most anyway) and as long as your not running a P4
your computer can run low powered too. shite, the acer 995 sempron
laptop would work well in an alternate power environment.
Houses don't need to use much power,just people are mindless about
leaving things on when not needed.
"Matt2 - Amstereo" ** Huh ?
You have a gas powered washer ??
You do not own an electric jug ??
I bet your hot water is gas though.
Plus I bet you live where the climate is warm. ** Many residences have no gas appliances or supply.
A small electric water heater takes 3.6 kW.
A basic electric stove takes 5 kW when the oven and 4 tops are all on.
A small room heater takes 2kW and an electric jug the same.
On a cold evening, while cooking dinner - the whole lot may be on.
That is over 10 kW not counting lights, TV or fridge.
no,. refering to hot water you know dishes, shower etc
Yeah but im refering to being able to run most / all heating without
electricity meaning that alternative power is viable
As i said above we have natural gas
No, ipswich is always colder than brisbane in winter, however jumpers or
jackets are great money savers
easy to have fitted or installed (a must for alternative electricity)
and the savings are pretty good to.
no good for alternative electricity
no good for alternative electricity
no good for alternative electricity
Gas is a clean viable and cheap alternative for all these. (and yes you
can get gas fridges, though the costs may or may not be different
Any thing that envolves heating can be run on gas. I perfer to cook on
gas simply because of control and instance.
The orig poster was on about alternative energy, i don't think hed go to
all the trouble of fitting a collector / bank just so he can use it for
burn an element. Resistive heat is the most draining on any power
system, using a burning flame is by far the most efficient way of
heating somthing. Gas matey, Gas.
**Sprouting an old myth does not make it true. I suggest you do some actual
research before you make a comment. FYI: The actual figures for payback
(energy required for manufacture) is more like 4-5 years. **Depends on the cells. **And it will create noise and pollution in the process. Solar cells are
silent and do not produce pollution. **And far less convenient, noisy, polluting, requiring maintenance, fuel,
etc. All in all, a complete PITA. It would also defeat the secondary purpose
of the whole system. It would, however, satisfy the primary purpose.
"Matt2 - Amstereo" wrote in
: The orig poster was on about alternative energy, i don't
think hed go to
: all the trouble of fitting a collector / bank just so he
can use it for
: burn an element. Resistive heat is the most draining on
: system, using a burning flame is by far the most efficient
: heating somthing. Gas matey, Gas.
I do share your sentiments on gas.
What a novel idea would be is to harness the great, untapped
methane resource that resides in Phil. He is just so full
of the "brown smelly stuff" you could power a small city on
After reading that "Strobe" thread I very much doubt anyone
**I just performed a more detailed analysis. Urk. I will require 20 X 115
Watt panels, not 10. That is, of course, assuming I don't make any
conservation moves. At present, I get by on around 13kWhr/day. Adding Solar
hot water should drop that figure by around 5kWhr/day. Give or take.
This will require more thought.
Here are the figures I'd researched a month or so ago for another
discussion. Solar cell makers buy surplus semiconductor grade
silicon for manufacture of their cells, so they should count the
energy cost to refine silicon to this stage. There are processes
to make "Solar grade" silicon out there but none are past the lab
stage of testing: these take 1/3 of the energy to make the silicon.
At any rate here is the figures I've come up with.
The calcs assume:
1. You are living on the sunniest place on the planet with 3000Hrs
of sun per year, somewhere on the equator on a cloud free plateau,
Sydney/Melb figures will be greatly reduced as you are closer to
the south pole at sea level in air pollution.
2. The solar flux is a constant unvarying 1.4Kw per square metre
from the sunup to sundown.
3. There is no age related loss of power at all(more like average 10%
and peaking at 20%).
4. You have invented some new way to slice silicon that has no losses.
The figure is closer to 50% at the thickness I have quoted.
5. The only energy costs are that to make the silicon, nothing else.
Please not that this does not count the lack of efficiency of energy
storage in batteries, the cost of making the batteries, the cost of
making the inverter, the cost of converting the silicon into a cell
the cost of refining the metals and glass used in the solar system or
the cost of shipping and installation.
6.It also does not count the multiple sets of batteries over the life
of the system.
7. It does not count the CO2 made during the chemical combustion part
of refining the silicon with carbon from quartz.
Here's what I'd researched earlier, Trevor on the 19/05/05:
"I've read it's a six step refining process that requires 2130 KW/h per
kilo of silicon. The density is 2330 kg/cubic metre, so assume you can
slice the silicon to 0.5mm thickness and have no sawing / polishing
waste and no energy expended to saw / dope / connect the cells,you'd get
2000 square metres of silicon for just under 5 GW/hours of energy. Solar
radiation is ideally 1.395 KW/metre square by 2000 square metres cell
area @ 3000 hours per year of sun under ideal conditions at the best
spot on the planet.
This gives 8.370 GW/hrs of energy per year by 15% cell efficiency to
give 1.255 GW/hrs per year of electricity.
so 5 GW/hrs divided by 1.255 GW/hrs per year gives 3.953 years to
cover the energy costs of making the silicon?."
payback = Four years???
So in a nutshell you get 3.953 years energy payback time assuming no
losses in the best part of the planet, assuming no energy losses, that
your silicon is at least 15% efficient?? and assuming no energy went
into making the solar cell from the raw silicon.
I would put it to you Trevor, that making the raw silicon into a panel
will double that figure, shifting the panel from the world's sunniest
site on a cloud free high altitude plateau on the equator to a region
far from the equator at sea level, like Sydney, would double that figure
again as you'd no longer have the CONSTANT 1.4KW per sq metre solar flux
I used in my calcs.
Finally a Telstra tech once told me that as a rule of thumb you
get half the energy out of a battery as you put into it, so your figure
would double again, so 4 years x 2 x 2 x 2 = 32 years assuming your
batteries never die, your inverter is 100% efficient and you solar cells
never age. If you could use/sell your solar power at the 24 Volts it
makes without needing to store or convert it you would still have a
payback of about 16 years.
The only commonly available cell on the market with any real
usable performance WILL have this problem....regardless of
what marketing tells you Trevor. There are experimental cells
of different design but they are not available retail yet.
It sounds like you've been listening to your solar cell
retailer Trevor, over it's lifetime, an alternator is
environmentally less polluting to manufacture than a solar
installation but would pollute more if run constantly all
day instead of when needed, which I thought your use would