From mining to blooming: Recycling bitcoin mining heat to power flower farming

Sustainable energy series, pt. 6

Introduction

Welcome to the before last article in our sustainable energy series! In the previous five articles, we explored the potential of five different energy sources that are generally labeled sustainable for powering the very energy intensive process of bitcoin mining and other blockchain mining activities. 

For this article, we want to look from a slightly different angle. Bitcoin mining uses large amounts of energy to add blocks to the blockchain and reap the bitcoin reward, but the computers miners use for this also generate a lot of heat. We found two great examples of people using this heat, that is otherwise simply lost, in other processes. In the Netherlands, a flower farmer uses residual heat from mining to heat the greenhouses. Meanwhile in Norway, a miner recycles the generated heat to dry out logs for the timber industry. 

We think these are two great examples of making the most out of the intensive energy use of bitcoin mining. That is why we will briefly explore these two recycling cases, in the hope that this might inspire more miners to find synergies with other sectors and use every bit of electricity as efficiently as possible.

Bitcoin mining heats greenhouses

Greenhouses require a lot of heat

The Netherlands is famous for their greenhouses, which produce a wide variety of vegetables, fruits, and, of course, flowers. Greenhouses require al lot of energy for ventilation, cooling, lighting, and heating. In the relatively cool sea climate, heating is especially important in the months when temperatures are still too low for many fruits and vegetables to be grown outside. Farmers have implemented all kinds of measures to reduce the energy use of greenhouses, such as double-glazed glass, thermal screens and other improvements to insulation. 

And since about a year or two, one flower farmer has another way of saving on energy and gas for heating: he uses residual heat from bitcoin mining. Bert de Groot, founder of Bitcoin Bloem, is the miner behind this idea. He saw an opportunity for both himself and the farmer, by getting access to cheaper energy while also reducing the farmer’s need to use natural gas to heat the greenhouses. It is not only more cost-efficient, but also more climate friendly, because energy is being used more efficiently and the farmer needs less or even none polluting gas heaters.

How does it work?

The process is simple: the bitcoin miner places his mining equipment in the greenhouse and pays the electricity bill for this. Because of the intensive computational processes that bitcoin mining requires, the mining devices produce a lot of heat. This heat is then being released in the greenhouse, where it keeps the temperature nice and warm for the flowers to grow. 

According to De Groot, the Netherlands are definitely a place where more miners could settle in collaboration with farmers with greenhouses.

Bitcoin mining heat dries wood for timber industry

Wood drying profits from mining heat

Whereas the Netherlands is known for its greenhouses, Norway has a large forestry and timber industry. It is in this country that a bitcoin miner, who already uses mainly renewable energy to power their mining activities, saw another opportunity to improve the efficiency of their energy usage. Kryptovault, Norway’s largest data center and bitcoin miner, uses hydropower as energy source for its operations, and the residual heat produced by the mining devices is being used to dry out logs for the timber industry. Moreover, the CEO also has ambitions to start the drying of seaweed with residual heat too.

Wood drying is energy intensive

The drying of logs harvested from the forest might be one of the most energy intensive parts of the timber industry. Timber drying is a crucial step in preparing wood for various applications, such as construction, furniture making, and woodworking. Drying wood before use is important, because excessive moisture in wood can lead to dimensional instability, decay, and the growth of fungi and insects. 

The timber drying process often uses natural gas as energy source, though heat from solar radiation is also being used. Solar radiation, however, is not always sufficiently available. Bitcoin mining devices generate heat 24/7, which is perfect for the drying of wood, reducing the need for natural gas and other additional energy sources.

Other applications of residual heat

The two examples we explored highlight the possibilities of using residual heat from bitcoin mining, to make the best use of all the energy the mining process requires and possibly help other sectors cut back on polluting energy sources. Other potential sectors where heat from bitcoin mining might offer an interesting opportunity include the heating of houses, industry, and water. 

Of course the feasibility of using mining heat for other purposes depends on the scale of the mining operation and the compatibility of the heat output with the requirements of the sector in question. Anyhow, it would be great to see more of such use cases in the future, including developments in technology and infrastructure to make collaborations between bitcoin miners and other sectors easier.

Conclusion

If these examples show one thing, it is that the recycling of heat from bitcoin miners offers an innovative solution to maximize the energy efficiency of the mining process. Of course, finding a way to reduce the energy needs of bitcoin mining should not be halted, but for now, the high energy use is inherent to the mining process. The examples of using the heat from mining in the Netherlands and Norway demonstrate the potential for collaboration between the mining industry and other sectors, leading to cost savings and reduced environmental impact. By optimizing the utilization of energy resources and promoting sustainable practices, these initiatives contribute to a greener and more efficient energy landscape.