Crypto basics

What Is Crypto Mining? A Plain-English Guide

Crypto mining sounds technical, but the core idea is simple. Here is what mining actually does, why it uses so much electricity, and whether it is worth doing at home.

21energy Bitcoin miners
Mining is how a blockchain secures itself, and pays for it Miners spend real electricity to validate transactions, and the network rewards them in fresh coins.
1 · What mining actually secures

Mining means securing a blockchain, not making coins from thin air

Crypto mining is the process that keeps a proof-of-work blockchain like Bitcoin running. Miners are specialised computers that bundle recent transactions into a block and then compete to solve a hard mathematical puzzle. The first to solve it gets to add the block and earns a reward in new coins plus transaction fees. The puzzle has no shortcut, so the only way to win more often is to do more computing, which is exactly why mining eats electricity.

So mining is not printing money. It is spending energy to keep a network honest, and getting paid for it.

2 · Why it uses electricity

The electricity is the whole point, not a bug

People often ask why mining has to burn so much power. The answer is that the energy is the security. Because adding a block costs real electricity, rewriting history or cheating the network would cost an attacker a fortune in power, and that cost is what makes Bitcoin so hard to tamper with. Other coins use different systems, some have moved to proof of stake which uses far less energy, but the big proof-of-work coins still rely on miners spending real electricity.

The power bill is not waste. It is the wall that protects the network.

3 · Not every coin is mined

Not every coin is mined the same way, or at all

Bitcoin is the original and by far the biggest mineable coin, and it is mined with purpose-built ASIC machines. Some other coins, like Litecoin or Dogecoin, are also mined, sometimes on similar hardware. Many newer coins are not mined at all, they use proof of stake instead. And plenty of coins you simply cannot mine profitably at home because big industrial operations dominate them. For most people at home, Bitcoin is the one that actually makes practical sense to mine.

If someone offers to mine an obscure coin for you cheaply, be careful. The honest game is mostly Bitcoin.

Which coins are actually mined
Mined with ASICs

Bitcoin, and coins like Litecoin or Dogecoin on similar hardware.

Not mined at all

Most newer coins use proof of stake instead of mining.

Mined, but not by you

Coins where industrial operations leave nothing for a home machine.

For someone mining at home, Bitcoin is the one that makes practical sense.

4 · What decides if it pays

Whether it pays comes down to one number

The maths of mining is brutally simple at heart. You earn coins, and you spend electricity. If the value of the coins you mine is higher than your power bill, you profit, and if it is not, you lose. Everything else, the price of the machine, the difficulty, the coin price, just feeds into that one comparison. For someone paying normal household electricity rates, mining alone usually loses. The people who win either have very cheap power, or they find a second use for the energy.

The winners are not the ones with the biggest machines. They are the ones with the cheapest, or double-used, electricity.

The electricity is not wasted if it also warms your home
The electricity is not wasted if it also warms your home Capture the heat and the biggest cost of mining turns into a second payoff.
5 · The second use, heat

At home, the second use is heat

This is where mining stops being a money pit for normal people. A crypto miner turns almost all the electricity it draws into heat. If that heat just escapes, you have paid for it twice, once on the power bill and once when you still have to heat your home some other way. But a miner that also heats your home uses the same electricity for two jobs at once, warmth you needed anyway, plus the coins on top. Suddenly the power bill is not a loss, it is your heating bill doing double duty.

That is the only version of home mining that reliably makes sense, and it is exactly what we build.

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The 30-second recap

  1. Crypto mining validates transactions and earns new coins for the work
  2. Proof of work spends real electricity on purpose, to keep the network secure
  3. Bitcoin is the main coin worth mining at home; many coins cannot be mined
  4. It only pays when the coins are worth more than the electricity
  5. A miner that also heats your home is the version that reliably works
Maximilian Obwexer

Maximilian Obwexer

Maximilian Obwexer is the co-founder and CEO of 21energy. He shares his expertise here on the blog and as a speaker at various conferences. The main topic is Bitcoin mining & its waste heat utilization.