[LINK] Hold up your hands if you Like HT Transmission Lines - Was - solar plants

[David Boxall]

On 24/06/2011 11:20 AM, Marghanita da Cruz wrote:
> David Boxall wrote:
>> On 21/06/2011 10:55 AM, Marghanita da Cruz wrote:
>>> David Boxall wrote:
>>>> ...
>>>> It would probably not be wise to encourage storage of energies of
>>>> those magnitudes by home-owners. Grid-connect and centralised storage
>>>> hold fewer hazards. Of course, the transmission lines should be
>>>> underground.
>>> <snip>
>>>
>>> Electricity transmission lines would need to be a long way underground.
>>> ...
>> Half a metre should suffice. It would certainly be safer than overhead
>> wires. Isn't it funny, how comfortable we are with familiar hazards,
>> simply because we're familiar with them?
>>
>
> Well you can see overhead power lines...I wouldn't like to put a shovel
> through a power cable...which has happened with presumeably shallow
> Telecom cables...
Telecom cables are typically about 30 cm below ground level (in my area, 
at least). Around here, 'phone cables are contacted less often than 
overhead electricity wires. I've known people injured and killed by 
overhead wires, and come close to being a casualty several times myself, 
which is why it's a bit of an obsession with me. Those wires might be 
comfortably familiar, but they're extremely dangerous.

> .. There is also the issue of broken cables and
> water...what happens in a earthquake/tsunami?
> ...
Not quite sure what you're getting at here. A broken cable is a broken 
cable, whether it's underground or overhead. An underground cable in 
water is no different to an overhead cable that's fallen in water. 
Believe me, once broken an overhead wire doesn't stay overhead.

As for earthquake, underground cables will be disrupted only at 
displacement planes. Those are surprisingly rare. Any pole or tower 
within hundreds of metres of a displacement plane will fall. In an 
earthquake, overhead lines are more vulnerable than underground cables.

-- 
David Boxall                    |  When a distinguished but elderly
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http://david.boxall.id.au       |  possible, he is almost certainly
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                                |  very probably wrong.
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