[LINK] transmission losses (was Re: Past the Black Stump - Was Hot Rocks

[Kim Holburn]

From:
https://secure.wikimedia.org/wikipedia/en/wiki/Electric_power_transmission
......

> Long-distance transmission of electricity (thousands of kilometers) is cheap and efficient, with costs of US$0.005–0.02/kWh (compared to annual averaged large producer costs of US$0.01–0.025/kWh, retail rates upwards of US$0.10/kWh, and multiples of retail for instantaneous suppliers at unpredicted highest demand moments).[7] Thus distant suppliers can be cheaper than local sources (e.g., New York City buys a lot of electricity from Canada). Multiple local sources (even if more expensive and infrequently used) can make the transmission grid more fault tolerant to weather and other disasters that can disconnect distant suppliers.

......

> Transmission and distribution losses in the USA were estimated at 6.6% in 1997[9] and 6.5% in 2007.[9] In general, losses are estimated from the discrepancy between energy produced (as reported by power plants) and energy sold to end customers; the difference between what is produced and what is consumed constitute transmission and distribution losses.
> 
> As of 1980, the longest cost-effective distance for DC electricity was 7,000 km (4,300 mi) (4,000 km (2,500 mi) for AC), although all present transmission lines are considerably shorter.[10]


......

> Cost of electric power transmission
> 
> The cost of high voltage electricity transmission (as opposed to the costs of electricity distribution) is comparatively low, compared to all other costs arising in a consumer's electricity bill. In the UK transmission costs are about 0.2p/kWh compared to a delivered domestic price of around 10 p/kWh.[14]

p/kWh = pence per kilowatt hours



On 2011/Apr/04, at 6:10 PM, Tom Koltai wrote:

> 
> 
>> -----Original Message-----
>> From: link-bounces at mailman.anu.edu.au 
>> [mailto:link-bounces at mailman.anu.edu.au] On Behalf Of Richard Archer
>> Sent: Monday, 4 April 2011 4:44 PM
>> To: link at anu.edu.au
>> Subject: Re: [LINK] Hot Rocks
>> 
>> 
>> At 4:31 PM +1000 4/4/11, Tom Koltai wrote:
>> 
>>> Err. I have to qualify that and confirm that my position as 
>> stipulated 
>>> in 2009 remains... Hot rocks are good if the consumers are 
>> within 99 Km 
>>> otherwise, transmission loss nullifies the benefit.
>> 
>> Victorian power generation is east of Melbourne.
>> Melbourne is between 150 and 200 km away
>> The biggest consumer is in Portland, 500+ km away.
>> 
>> So apparently your 99km limit is somewhat flexible.
>> 
> 
> Umm, not really. My understanding was that it was to be a 2 MW plant,
> with transmission loss on a cold day being 2kW per kilometre
> (conservatively) than the deliverable to 100 Km distance is only 90% of
> generated power.
> @ 200 kilometres, 80% of Gen. power.
> 
> For the Portland customer, they would only be able to deliver -200 kW.
> (yep minus 200 KW)
> 
> (Distance from Innamincka, SA, Australia to Portland, VT, Australia is
> 739.9 miles, 1190.8 km, or 642.6 nm. ) [1]
> (Distance from Innamincka, SA,Australia to Tullamarine International
> Airport, Melbourne, VT, Australia is 728.5 miles, 1172.4 km, or 632.6
> nm) [1]
> 
> This doesn't allow for any DC-AC, AC-DC conversions or Transmission
> step-ups or transformer step-downs.
> 
> As the majority of the plants income will be from offsets for delivered
> baseload green power, experience tells me that they want to deliver it
> <100 kms.
> Plus the cost of transmission lines to the closest Grid interconnect
> would be impossible to amortise (with only 2MW generated) in several
> lifetimes.
> 
> Nope, needs a refinery or steelworks or datacentre (within a 100Kms) to
> make financial sense - e.g. Port Pirie or Broken Hill are the closest
> non military industrialised towns. But in reality 2MW Baseload is enough
> to run about 6,000 country homes or 4,500 city homes. City folks have
> more "stuff" plugged in.) 
> 
> The problem is the transmission towers from Inna to anywhere...
> 
> For those that don't quite know where Inna (Hopetoun) is or have never
> had the pleasure of visiting the red centre of Oz...
> 
> Innamincka is perched in between the Strzelecki, Tirari and Sturt Stony
> Deserts.
> 
>> From Tibooburra, 224.82kms NW (314kms, 11hrs 17mins driving) 
>> From Birdsville, 247.01kms SE (418kms, 14hrs 14mins driving) 
>> From Marree, 335.35kms NE (541kms, 19hrs 34mins driving) 
>> From Quilpie, 371.18kms W (496kms, 13hrs 8mins driving) 
> (Google Maps links @ [4] below)
> 
> In other words... Too far for any Grid Connect.
> 
> For the purposes of testing - an excellent test bed which will no doubt
> result in a massive tourist resort being built there in the future.
> Hot springs in the desert - I can see it now... About Innamincka [3]
> (They need more hot showers - really....)
> 
> However, as a press release saying "lookee lookee, we have green power
> to the grid!!! Priceless. (I would be fascinated in seeing their
> proposal for getting the power to the grid.)
> 
> [1] http://www.distancefrom.info/Innamincka/ST/Australia/
> [2] Distance from Innamincka, ST,Australia to Port Pirie, ST, Australia
> is 415.4 miles, 668.6 km, or 360.8 nm
> [3] http://www.exploroz.com/Places/4716/SA/Innamincka.aspx
> [4]
> http://maps.google.com.au/maps?hl=en&client=firefox-a&hs=aGK&rls=org.moz
> illa:en-GB:official&channel=s&q=innamincka+google+maps&um=1&ie=UTF-8&hq=
> &hnear=Innamincka+SA&gl=au&ei=nXaZTZ-GOI6avAPrxMD2Cw&sa=X&oi=geocode_res
> ult&ct=image&resnum=1&ved=0CBcQ8gEwAA
> 
> /body
> 
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Kim Holburn
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