How people of Kyiv heat their houses and water by bitcoin mining

During operation, any computing device generates heat that needs to be utilized (which is why some IT companies build their data centers in cold climates). Mining boilers are actually cryptocurrency miners connected to the heating systems of the house, they can be used to heat up the water in the boiler or underfloor heating. In the examples that we will look at, Hotling WX6 mining boilers are used. They are developed by Hotmine company based in Kyiv and are based on Bitfury chips. This boiler is a “box” with boards with Bitfury chips weighing 9 kg, with a computing power of 10 Thash/s.

The experiment with the use of such equipment within residential premises began in 2013. Back then, the company’s specialists suggested that the owners of private houses in the cottage in Kruglyk near Kyiv try to install such boilers for heating of the houses. In total, six home owners agreed to participate in the experiment. Two of them bought such boilers (with cost from $5,000 for one boiler), they profited from mining. The rest of the experiment participants installed boilers at home for heating and were compensated for the energy expended on equipment operation.

These boilers began operation in November 2013 and operated year-round until 2015. In that year, the equipment was turned off, due to the fact that the remuneration to homeowners was no longer enough to pay for energy. In the winter of 2017, there was a jump in the cost of Bitcoin, the equipment was switched on again for three months of the winter period, in the same houses. In 2018, the version of the WX6 boiler was updated and it was plugged in again in one of the houses (especially since the entire infrastructure for the connection was already ready in the house).

Such boilers are connected to boilers and floor heating systems. The miner uses boilers, inside of which there is a heat exchanger. “The miner-boiler heats the water inside the boiler through the heat exchanger, it is connected as an ordinary electric boiler. In such devices there are two outputs or pipes. The water enters one of the pipes, and comes out in the other one, but it’s already 5-7 degrees warmer. Then the water enters the floor heating system and returns with a lower temperature, then heats up again and again in a circle. Spent 1 kW of energy heats about 10-15 square meters rooms,” explains Slobodenyuk.

How does it look in numbers?

With the same equipment the entrepreneur heats his apartment and a garage in Kyiv, we are talking about a two-room apartment of 56 square meters. On average, the floor can be heated to 30 degrees Celsius, water – to 55-58 degrees.

Two miner-boilers with a total capacity of 3 kW/h are installed in the entrepreneur’s garage. For a month, the costs look like this: 2100 kW/h x 1.68 = 3444 UAH, for the same period the miners earn about 4500 UAH. The temperature in the garage is about 18 degrees Celsius.

How much heat will be needed to heat the house? One mining boiler replaces one battery. It conditionally consumes up to 1 kW/h. In a private house, on average 6 heating batteries will be enough for 100 square meters:

6 kW/hour x 24 hours = 144 kW. 144 kW x 30 (days per month) = 4320 kW. Further, if we take the electricity prices in 2018 for the private sector, it will be 1.64 UAH per kWh during the day (and half the price at night), which means, on average, about 1.4 UAH per kWh (about $0.05).

Conventional heating equipment works intermittently: when the house is heated, it is turned off, then switched on again. The mining boiler should work 24 hours a day. Equipment receives $0.08 per 1 kW/h from mining. A typical connection project for a private house with equipment specifications can be found here.

Bitcoin prices fluctuate, however, as long as the “plug” between the cost of electricity and the value of the extracted cryptocurrency remains, such equipment makes sense, says Slobodenyuk. “Now the difference is $0.03. Even if the cost of Bitcoin drops to $3,000, there will be no income, but the equipment will still compensate for the cost of electricity,” he says.