 | We're Off To See The Wizard - Storing Energy Using Ammonia | TOD: Australia/New Zealand | The Bullroarer - Thursday 1st May 2008 |  |
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If and probably.
The fundamental assumption here is that things will remain the same.
Doing the analysis this way when we know that things will not remain the same is questionable.
Knowing, as the author indicates he does, that things will not remain the same, the question is "How much are you prepared to pay for light?" NOT I will get 6% (with a possible recession imminent) or more if I put it into a fund (really, given recent history?).
I await the input of those with solar on their roof, but I do question the requirement for large systems before you qualify for these rebates. Why not for smaller easier to install systems that just run your lights? At least at first, what if we ALL did that? Instead of a small minority of us attempting to run our entire house on solar?
But it is interesting the libs have made this move... maybe to differentiate themselves from those coal fired unionists running the labour party...
The trouble with small 240v systems is the relatively fixed cost of approved inverters, costing at least a few hundred dollars. The powerco may or may not spring for the cost of an import-export meter. These are digital with no spinning disc. As a next step these could be integrated with appliance controllers.
If we are going to try and charge battery cars at home we really need bigger systems, say 5 kw peak. In sunny weather that might generate 20 kwh per day. I believe car-to-grid PV or house based microstorage would be a more robust solution to baseload than concentrating solar. Steam boilers out in the desert will disappoint when it rains for a week and there is machinery to break down as well as line losses. The trouble is that long cycle life batteries are exorbitantly expensive, as is polycrystalline silicon. We need major cost cuts (say 80%) in both PV and batteries.
What sized system would you need to install to power household lights (low power or LED) at 12V?
Not 240V. No inverter. No exporting to the grid. No plug in cars.
Good question since I haven't used fixed LEDs yet. A 12 volt, battery or campervan dealer may be able to advise. You also want to think about concealed wiring and unobtrusive switches. A single panel (say 40w peak) tilted north charging a deep cycle lead acid battery (say 40 Ah) via a voltage regulator will prevent overcharging, excessive drawdown and voltage taper. You want to wire the LEDs or fluoros in parallel so each light gets the 12v then add up the amp hours to make sure the system can cope. Put it together in the shop before taking it home. I suspect if you want reading quality light in just one room you could be looking at least $A500 ie it will take years to pay back if the existing lights are mains powered.
So for about a bit over a thousand (say) you could probably run most of the lights in a house? Given that not all lights are on at the same time... for very long.
So the $8000 could be used to subsidise that many more houses, converting them all to run just the lights on solar - which is between 10 - 20% of the power used in a house.
Because even with that $8000 subsidy, only the truly motivated are going to go ahead. It's a big operation. But just doing the lights might see a greater uptake. I'm guessing that it should really only be a day (or two) to do the conversion.
Further, if it were mandated that all new houses, where possible, should be built this way from the outset... then the financial "payback" argument is moot.. surely.
In the event of cloudy weather, the lights of course can still be powered by the mains using a 240V to 12v power supply or simply a battery charger... still cheaper than an inverter.
That's what I'm getting at... how to migrate usage to solar.
Thanks Boof.