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Forum Index : Solar : how do you value renewable energy?

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yahoo2

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Joined: 05/04/2011
Location: Australia
Posts: 1166
Posted: 04:47pm 26 Jan 2017
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I have attempted to write a post about the costs of renewables versus fossil fuel centralised power generation.
It has taken six months and I am no closer to finding a way to compare the two.
Man it is tuff!

it is easy if I do a straight swap of technologies. for example

Household "no clue Norm" just wants to replace his current use, 15 kwh day and 24 kwh night use with solar or something.

A few quick calculations and we have costs laid out in dollar per week and cents per kwh. its like shelling peas!

The big problem is, I have never had a Norm as a client. This example of direct replacement, like for like, never happens and even if it did happen it is such a poor implementation of renewable energy that the savings that are made are well short of what is possible. It gets hard to cost things like insulation versus air conditioning and allocate a percentage to the budget or bottled gas vs electric for cooking.
this also applies to
refrigeration
whitegoods
computers and tv's
transport
pumping water
lighting
working hours/time at home
each one of these choices have a big impact on the bottom line. they directly affect the size of the inverter to handle peak loads and the nightly power cost of a grid connected system or the size of the battery bank.

The other glitch is that renewable energy is all upfront cost so every major component is amortized over its estimated life and replacement cost, sometimes the best I can do is take a punt and guess how long something will last. I tend to be conservative with lifespan and hope to be pleasantly surprised.

What I can say is that in a place like South Australia that has high power prices, a mild climate and good sun all year it is not hard to make a massive dent in the cost of electricity.
How big?
its not hard to halve the cost for a household that is already efficient, for the rest of us power wasters 75% drop in costs is easily do-able.
I'm confused, no wait... maybe I'm not...
 
Gizmo

Admin Group

Joined: 05/06/2004
Location: Australia
Posts: 5078
Posted: 06:40pm 26 Jan 2017
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We've been trained to use energy. Having the big air conditioned house, dish washer, cloths dryer, etc, are now considered essential, where 30 years ago they were luxury items. Most of us grew up without these things. I myself refuse to have a dish washer, I consider them the height of laziness, but you try suggesting to a young family they dont need a dish washer! Same with the suburban 4WD, a poor handling fuel guzzler thats a pain to park, expensive to run and never goes off road, but just about everyone has one. I dont.

If people ask me about my off grid power, I tell them I can do anything you can, but I may need to time it differently. Use power hungry stuff during the day. A few small changes to your daily schedule can have a big effect on the installation cost of a off grid setup. Take responsibility of your power consumption, and you can save thousands of dollars in the installation and cost of living. I also mention my power is more reliable than grid power.

I find some people are genuinely interested, you can see them considering it, but others are just not interested, you hear the "Oh the wife wont like that!" remark.

Glenn
The best time to plant a tree was twenty years ago, the second best time is right now.
JAQ
 
yahoo2

Guru

Joined: 05/04/2011
Location: Australia
Posts: 1166
Posted: 10:40pm 26 Jan 2017
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OK perhaps I will put some numbers on it.

I think the best numbers I have seen as of now (January 2017) for an approx 20kwh/day household are,

off-grid and hybrid on-grid
under AU$22.00 per week
cutting edge system under $17.00 per week

grid connected (no storage, 6.5 cent feed in tariff and buy power at night @35 cents)
$12.80 - $17.00 per week

grid with no renewable's consuming the same amount would be between $42.00 and $46.00 per week with a standard contract.

I'm confused, no wait... maybe I'm not...
 
Madness

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Joined: 08/10/2011
Location: Australia
Posts: 2498
Posted: 10:42pm 26 Jan 2017
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I have air conditioning, dishwasher, 65" TV, side by side fridge with ice maker etc all running off grid. We have to be careful with the AC but with properly insulated house that would be very different. Apart from that we just live the same as the people described above would. I refuse to live without them and without the grid. Been through one divorce thats enough for me.
There are only 10 types of people in the world: those who understand binary, and those who don't.
 
yahoo2

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Joined: 05/04/2011
Location: Australia
Posts: 1166
Posted: 08:51pm 29 Jan 2017
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I like looking at things in dollars per week.

it is a very good comparison between spending and investment savings. Mainly because all those tiny amounts we spend each week add up quick.

Francesca's financially frugal family that drops their on grid costs of $46 per week down to $16 per week and invests the $30 a week for ten years at a compounding 5% in a managed fund.

over ten years we are looking at this.



twenty grand! really? I mean $30 a week is the sort of money we could spend on takeaway coffee.
The average cheap family sedan probably costs $100-200 per week to own and operate.

So if we compare that to "norm's family" if we can get them down from $150 per week to $25 per week for electricity.



So, if we have a weekly cost or saving we could make, multiplying that amount by 670 will give the 10 years of compounding deposits @ 5% interest.

PS 40 years ago my parents paid $4.09 per week for using 20Kwh/day grid electricity.
Edited by yahoo2 2017-01-31
I'm confused, no wait... maybe I'm not...
 
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