user117: Obviously, the computing power necessary to create the blockchain requires access to fast hashing which requires electricity. Given that local power outages do occur, and this can cause a lack of network availability, does this act as the Achilles heel for Bitcoin?
Is it possible to conduct Bitcoin transactions in the absence of electricity?

user409: In theory Bitcoin could work without electricity or computers. The difficulty would be (manually) reduced so that calculating the hashes by hand (or mechanical means) was feasible. Transactions would have to  propagate on paper by hand. Transaction fees would have to go up enormously. And the whole shebang would work at a medieval snail's pace. I imagine it would be like scribe monks copying and verifying bibles...

user323: The network is distributed, so it won't go down everywhere at once.
Locally, on one hand it is similar to debit transactions - they need to get online to be processed. One can use cellphones though, which have their own batteries to run for awhile, so it's not too bad.
Lastly, one can accept transactions offline (using QR codes for example) and later transmit them through the network, but that carries the risk of double spending.
And if you want truly offline transactions with little risk, use things like Casascius physical Bitcoins.

117: <p>Obviously, the computing power necessary to create the blockchain requires access to fast hashing which requires electricity. Given that local power outages do occur, and this can cause a lack of network availability, does this act as the Achilles heel for Bitcoin?</p>

<p>Is it possible to conduct Bitcoin transactions in the absence of electricity?</p>
 409: <p>In theory Bitcoin could work without electricity or computers. The difficulty would be (manually) reduced so that calculating the hashes by hand (or mechanical means) was feasible. Transactions would have to  propagate on paper by hand. Transaction fees would have to go up enormously. And the whole shebang would work at a medieval snail's pace. I imagine it would be like scribe monks copying and verifying bibles...</p>
 323: <p>The network is distributed, so it won't go down everywhere at once.</p>

<p>Locally, on one hand it is similar to debit transactions - they need to get online to be processed. One can use cellphones though, which have their own batteries to run for awhile, so it's not too bad.</p>

<p>Lastly, one can accept transactions offline (using QR codes for example) and later transmit them through the network, but that carries the risk of double spending.</p>

<p>And if you want truly offline transactions with little risk, use things like <a href="https://en.bitcoin.it/wiki/Casascius_physical_bitcoins">Casascius physical Bitcoins</a>.</p>
