You can most certainly mine, you just can't do so at a profit with electricity costs of $.21/KWh. If your primary motivation for mining to make money, then you'll have to host your machine somewhere else with a lower electricity cost.

Sorry, but this grows ever more common across the world. Mining will continue to migrate to areas with the lowest electric cost.

I haven't seen any alt coins that can be mined for a profit at that rate, but I could be wrong.  I got out of the alt market last summer when I saw the trend slowing down.

Nowadays mining Bitcoins is becoming worthless day by day!

This is only due to bigger miners with tons of Antminers/Spondoolies.

If you want to mine for a living, then consider buying 1000 of miners at once and make a personal mining hub for your own, or just quit thinking about mining since it's no longer profitable at all!

Bitcoin-mining is stepping towards centralization!

Coinwarz is just good for current period. It's horrible long term as no difficulty change.  Use one like https://bitcoinwisdom.com/bitcoin/calculator  .  With it you can add difficulty.

But OP your could mine... just is not profitable and you won't roi on machine unless you mined with it and somehow sold for most of what you paid.  But would all involve selling.  Better solution is looking into hosting.  You can host at places much cheaper and you stand a chance at ROI.

Your electricity price seems that is very high, maybe because it is the winter season? for the moment i don't think it worth mining even with s7.

You might make a short term profit, but you won't even come close to making enough back to pay for ANY currently available miner before it goes unprofitable (if it EVER makes a profit).

 Cryptocoin mining is a low-electric-cost game if you want to make anything at it.

If you want to support bitcoin better to set up a business that utilizes the coin instead of trying to mine with 21c/KWH.  It's just not feasible.

Why bother paying those rates, buy some hash on hashnest and you will pay about 10 c a kw/hr, its the best option for situations like this.  When you want to cashout just sell your hash power on the market.

If your electricity is $0.21/kWh, it is better not to mine if you do not think mining is your hobby. There are mining farms in China, paying $0.04/kWh.

Honestly I wouldn't do it i mate. If it is a hobby then go ahead, but if you want some profit too it, it is a No Go.

In my country the price for elecrictiy is also very high. I try contact some datacenters and tried mining there, but eventually you are caught up with difficulty etc.
If you really want to mine, you could buy a second hand GPU and go for Monero or even Ethereum. This way it is more cost efficient.