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href=3D"http://en.wikipedia.org/wiki/Dinorwig_Power_Sta
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Hi Chris & All, Aug 29, 2012
Thanks. I just bought a used copy of Monbiot's book, in reputed good =
condition, from Amazon.com for $0.01+ postage. Hope that price is a =
reflection of widespread use in College as opposed to intrinsic value. =
Perhaps it will explain why electrolysis is so inefficient.
Yt, DW, Kentville
----- Original Message -----=20
From: Christopher Majka=20
To: naturens@chebucto.ns.ca=20
Sent: Wednesday, August 29, 2012 11:36 AM
Subject: Re: [NatureNS] wind power storage
Hi Dave,
On 29-Aug-12, at 10:48 AM, David & Alison Webster wrote:
Dear All, Aug 29, 2012
An objection to wind power, that continues to surface, is the =
failure of potential wind generation to reliably match demand for =
electricity.
Are there compelling reasons, given suitable topography or =
infrastructure, why excess wind power could not be stored by pumping =
water to a higher reservoir or by generating hydrogen ?
Geoge Monbiot's book "Heat: How to stop the planet from burning" =
includes an extensive discussion of this topic.=20
By far and away the most efficient way to store energy generated from =
wind is in reservoirs (i.e., pumping water uphill when there is excess =
wind supply and then letting it flow downhill through a turbine to =
generate electricity when demand is greater). Depending on details of =
how the reservoir and generation system are constructed losses involved =
in such "pumped storage" are only in the range of 20-25% (i.e., one is =
able to recover 75-80% of the energy that goes into the process).
This is much better than any of the alternatives such as electrolysis =
of water or compressing air in underground caverns which typically =
involve losses of 60% or more.=20
There are other more exotic possibilities such as flow batteries, =
flywheels, or superconducting magnets that can store limited amounts of =
energy and only for short periods of time.
However, there is another way of skinning this cat. Electric =
transmission lines in most of the world use AC (alternating current) =
which has no inherent capacity to store energy. However, some =
jurisdictions are moving to high-voltage DC (direct current) lines (for =
a large variety of reasons too lengthy to go into here). The upshot is =
this: a large DC line (there is already one in Africa that runs 1,700 =
km) functions to some degree like a very large battery. One can (within =
limits) continue to pump electricity into it, progressively stepping up =
the voltage. Then when you need power you run it out of the line through =
a transformer. The more extensive a DC grid the greater the overall =
capacity of the "battery." Moreover, with the development of new =
high-voltage DC valves and much lighter wires the costs of DC =
transmission are dropping sharply and their environmental impact is =
less.
Cheers!
Chris
Christopher Majka - columnist, Rabble.ca
Halifax, Nova Scotia, Canada
Email: c.majka@ns.sympatico.ca
http://rabble.ca/blog/26142
"The significant problems of our time cannot be solved by the same =
level of thinking that created them." - Albert Einstein
No virus found in this message.
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08/29/12
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style=3D"WORD-WRAP: break-word; -webkit-nbsp-mode: space; =
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bgColor=3D#ffffff>
<DIV><FONT size=3D2>Hi Chris & All, =
=20
=
Aug=20
29, 2012</FONT></DIV>
<DIV><FONT size=3D2> Thanks. I just bought a used copy =
of=20
Monbiot's book, in reputed good condition, from Amazon.com for =
$0.01+=20
postage. Hope that price is a reflection of widespread use in College as =
opposed=20
to intrinsic value. Perhaps it will explain why electrolysis is so=20
inefficient.</FONT></DIV>
<DIV><FONT size=3D2>Yt, DW, Kentville</FONT></DIV>
<BLOCKQUOTE=20
style=3D"BORDER-LEFT: #000000 2px solid; PADDING-LEFT: 5px; =
PADDING-RIGHT: 0px; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px"=20
dir=3Dltr>
<DIV style=3D"FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV=20
style=3D"FONT: 10pt arial; BACKGROUND: #e4e4e4; font-color: =
black"><B>From:</B>=20
<A title=3Dc.majka@ns.sympatico.ca=20
href=3D"mailto:c.majka@ns.sympatico.ca">Christopher Majka</A> </DIV>
<DIV style=3D"FONT: 10pt arial"><B>To:</B> <A =
title=3Dnaturens@chebucto.ns.ca=20
href=3D"mailto:naturens@chebucto.ns.ca">naturens@chebucto.ns.ca</A> =
</DIV>
<DIV style=3D"FONT: 10pt arial"><B>Sent:</B> Wednesday, August 29, =
2012 11:36=20
AM</DIV>
<DIV style=3D"FONT: 10pt arial"><B>Subject:</B> Re: [NatureNS] wind =
power=20
storage</DIV>
<DIV><FONT size=3D2></FONT><FONT size=3D2></FONT><BR></DIV>Hi Dave,
<DIV><FONT size=3D2></FONT><FONT size=3D2></FONT><BR>
<DIV>
<DIV>On 29-Aug-12, at 10:48 AM, David & Alison Webster =
wrote:</DIV><BR=20
class=3DApple-interchange-newline>
<BLOCKQUOTE type=3D"cite">
<DIV>Dear All,=20
=
&=
nbsp; Aug=20
29, 2012<BR> An objection to wind power, that continues =
to=20
surface, is the failure of potential wind generation to reliably =
match=20
demand for electricity.<BR><BR> Are there compelling =
reasons,=20
given suitable topography or infrastructure, why excess wind power =
could not=20
be stored by pumping water to a higher reservoir or by generating =
hydrogen=20
?<BR></DIV></BLOCKQUOTE></DIV><BR></DIV>
<DIV><FONT size=3D2></FONT><FONT size=3D2></FONT><BR></DIV>
<DIV>Geoge Monb