Ok but given current pricing of GPUs, is it profitable to mine the coins, given I have access to free electricity (my office building does not charge for that).
"They are" is the wrong pairing. The subsidy halves every 210,000 blocks (~4 years) as part of the innate core rules of the system enforced by every participant.
So it would be more accurate to say "They cut" (past tense as this was established years ago), or "The system will" (no human actor).
Also it looks like the halving will be early December to late November. (The block number is fixed, not the time, and because the difficult updates lag rapid increases/decreases in computing power can shift the date around a bit)
>Before investing significant amounts in mining equipment those operators who rent and plan to take advantage of utilities being included might wish to review the lease documents to become aware of any “commercial use” exclusions. Also they should be aware of the potential that a month-to-month lease could suddenly change where utility submetering or other cost transfer might be imposed.
This might make a lot of GPU setups obsolete.
Edit to add more info: I'm told the expected generation output, from 1000000 Mhps, at current difficulty 1751454.53534068, is 574.2818 BTC per day or 23.9284 BTC per hour.
Even if this were the case, the gains from such a scheme would be short-lived, though, as the difficulty adjusted to compensate. Then you're competing with everyone else who has bought these, and fighting over the marginal cost of electricity vs. the upcoming reduction in the reward.