[LINK] [PRIVACY] BT: 'Are meters too smart by half?'

[Richard Chirgwin]

Tom Koltai wrote:
>   
>> -----Original Message-----
>> From: link-bounces at mailman1.anu.edu.au 
>> [mailto:link-bounces at mailman1.anu.edu.au] On Behalf Of 
>> Richard Chirgwin
>> Sent: Saturday, 26 June 2010 6:35 PM
>> To: link at anu.edu.au
>> Subject: Re: [LINK] [PRIVACY] BT: 'Are meters too smart by half?'
>>
>>
>> I'm resending this without the previous post because something is 
>> scrambling in the fonts.
>>
>> I have some friends in the Southern Tablelands who have never been 
>> "on-grid". The place was solar from day one, mostly because that was 
>> cheaper than getting someone to run a line several km for the grid 
>> connection. The only missing "mod con" is an air conditioner.
>>
>> In what way is a system like that not sustainable?
>>
>> RC
>>
>>     
>
> At 15% or below electricity efficiency, a cost comparison is appropriate
> - and is compared with city Grid pricing kWh.
>
> Capital replacement cost of Solar Panels, every 6 to ten years. (I don't
> care what they say in the manufacturing brochure. Anodization results in
> eventual replacement!!! Anodization is an effect of acid rain and
> electricity generated. If you live in a city, then your rain has a lower
> PH than if you live in a non power station polluted rain area.)
> Maintenance cost of replacement parts and cleaning of the solar panels
> (Bird residue, dust storms etc)
>   
OK. First, let's look at panel replacement. The panels I have in mind 
are about 10 years old and still operating at about 95% of rated 
performance. Admittedly, they're not in a city.

Cleaning them takes a couple of hours, every few months. It's  hardly an 
intolerable burden.
> Battery replacement cycle for a home with 2.3 kids averaging 3.45 kwh
> per day (18 mths - 36 months depending on whether dry or wet cell
> batteries are utilised - if a compressor based refrigerator or aircon is
> used, chop those numbers in half).
>   
This seems out of step with my experience. At about eight to ten years, 
they're definitely seeing a loss of performance, but the sensible thing 
to do is to over-spec the batteries at the start. The other all-solar I 
know of, in the Blue Mountains, is reaching the point where battery 
yield is a serious issue - at about 15 years from installation (back in 
December, I checked the manufacture date on the batteries).
> If on the other hand, one is prepared to accept 12V fluoro lighting,
>   
They're running 240V everywhere. The lighting isn't any problem. There's 
enough to spare for a plasma TV and - in summer at least - a bread machine.
> solar hot water with no electrical water heating required, gas cooking
> opposed to electrical hotplates and oven, 
Gas - vs - electrical cooking is a matter of taste more than a compromise.
> then yes, a compromise
> efficiency scale can be reached, but not really comparative with city
> living standards. 
>   
The question of "living standards" is mostly too subjective to yield 
sound decision-making. Everybody, wherever they live, compromises their 
personal ideal against cost, and makes a trade-off.

For example, is the rule "don't light empty rooms" an intolerable loss 
of living standards, or sensible economy?

RC
> There is only one, in my experience, cost efficient alternative power
> system and that is mini-hydro, if one is lucky enough to live near a
> stream.
>
> Combining alternative energy systems appears to be the winning
> combination of capital cost efficiency and stable output power
> resulting...
>
> E.g.:  Wind, methane/turbine and solar together can be installed for an
> individual home for around 32 k (USD$ approx).
> The batteries will need replacing every three years (maximum) and wet
> cell appears more reliable than dry cell.
>
> Maintenance costs for the three energy systems total approximately 1800
> per year.
>
> Currently that exceeds grid power charges... Well until July 1st that
> is... After which it might be worthwhile recalculating.
>
> A lot of my data into solar comes from utilising it between 1984 and
> 1994 in Darwin, NT. At that time of course, Solar panels operated at
> efficiency levels sub 7%. Even with the long tropical days and higher
> number of sunshine days.
>
> Anecdotally, we did manage to run one 5200 BTU (small) aircon in a
> bedroom for 12 hours per day, but it killed the batteries and we were
> replacing them every 12-13 months.
>
>
> What many forget is that modern digital componentry requires stable 60
> Hz sine wave power supply.
> The requires an additional USP AC filter that comes in at $1200 dollars
> (per 300 watts) and requires it's own batteries separate to the inverter
> batteries.
>
> Anyone ignoring this requirement will end up with lots of dead pixels on
> their LCD screens and failed hard disks and power supplies on their
> computers.
>
> Living off grid successfully is hard AND expensive. Sustainability
> determination is often dependent on costs not immediately apparent in
> the basic setup and running costs. In my earlier email I suggested that
> solar systems that didn't operate at a minimum 15% efficiency were
> unsustainable. I would like to add the following qualifying words to
> that... "IMHO"
>
> My experiences include alternative energy projects in several countries
> globally, including Jabiru, N.T. solar; Nevada (geothermal) & Solar;
> Nauru, Solar and evaporative, Hungary, PBMR and here in Aus, AJ Bush and
> Methane powered Capstone Turbines.
>
> Tom 
>
>
>