Writing a terabyte of information at 10c/kwh would cost $3.78 [1]. Not nothing, but doesn't seem entirely impractical for all cases.
Heat dissipation might be an issue?
[1] https://www.wolframalpha.com/input?i=17+%CE%BCJ+%2F+bit+*+1+...
Heat dissipation might be an issue?
[1] https://www.wolframalpha.com/input?i=17+%CE%BCJ+%2F+bit+*+1+...
That means you'd not only have to deal with the heat dissipation of ~five space heaters at full power, but you'd also need three-phase power to supply it.
So you yourself are saying anything longer than a month is unreasonable?
In any case, this lab experiment will need much improvement in speed and energy requirements.
And it seems like writing to HDDs is between $.15 to $.56 per TB depending on write speed and watts/time assumptions. It gets tricky to think about because there the sunk cost of powering the drive when idle, and the delta between idle and write power needs, but I think that range is representative for $/TB on a HDD.
Wolfram link: https://www.wolframalpha.com/input?i=20w+*+second%2F100MB+*+...
That seems obviously wrong (writing a TB will consume less than 1 kWh), and indeed your link shows 0.56 cents (i.e. $0.0056) per TB.