ZEC's recent surge has attracted many miners' attention, but before getting a mining rig, there are several key issues that must be clarified.

**Hashrate looks strong, but profits are shrinking**

The Z15 Pro with 840K hashrate is indeed impressive. Based on current data, the daily output per machine is about 0.1-0.11 ZEC. At a coin price of $500, the rough daily gross income is approximately $55. But this is just on paper.

The problem is that the total network hashrate is soaring—up 30% in two months—and the difficulty is rising accordingly. Today, you might mine 0.11 ZEC, but next month it could drop to 0.09. The more people participate in mining, the smaller the share for each miner—this is a fundamental rule of the mining industry.

**Electricity costs are the real profit "killer"**

Many calculations assume an electricity cost of 0.3 yuan per kWh, making the daily power consumption only 20 yuan at this rate. But in reality, most people use commercial grid electricity, which costs up to 0.78 yuan per kWh. As a result, the daily electricity bill jumps to 52 yuan, and net profit is instantly halved.

Even more critically, mining machines are not static. As usage extends over time, fan wear and chip aging will increase power consumption by 5%-10% annually. In later stages, electricity costs占比 will become higher and profits will shrink—this is an unavoidable fact.

**Payback period figures may be misleading**

The claim of a 98-day payback sounds very attractive, but the premise is overly idealized.

As a privacy coin, ZEC's price can be highly volatile. It has surged over 1460% this year, but such coins also face significant regulatory risks. Policy adjustments could cause sharp declines.

Additionally, mining hardware updates rapidly. The Z15 Pro is no longer the latest model. Chip manufacturers release new models every year, and newer machines can easily outperform older ones. When that happens, your equipment might lose its competitiveness.

Overall, the profit model of mining seems simple, but in practice, there are many variables. Besides hashrate costs, you also need to consider coin price risks, rising electricity costs, and machine depreciation over the long term.