Or the introduction in to how combining Bitcoin mining and Stirling engines can help humanity become a type I civilisation on the Kardashev scale
In 1964 Soviet Russian astronomer Nikolai Kardashev proposed a method for comparing the level of technological advancement for hypothetical space-faring civilisations. In the Kardashev scale civilizations are categorised in to three types: Type I civilisation is able to utilise all the energy resources of its home planet, Type II of its solar system, and type III of its galaxy. Using this method of measurement, our human civilisation is not yet on the radar, but as the quest for utilizing renewable energy sources accelerates, we are rapidly approaching level I, or mastery of our planetary resources. In this article I will probe how Bitcoin mining could help us reach the status of a planetary civilisation.
By now most people have at least heard of Bitcoin – the peer-to-peer payment network that became a global phenomenon and sparked the cryptocurrency revolution. Bitcoin is such a multi-dimensional thing, it’s very difficult to describe it in it’s totality: it’s technological, it’s social, it’s economic and it’s changing the way people transact with each other on the fundamental protocol level; people can now transact with each other directly, peer-to-peer, without a trusted third-party, such as a bank.
We can look at Bitcoin as a currency, as a protocol, as a public ledger, or we can look at it as a sort of a social movement, a global network of people connected through the internet, but for now, let’s think of it as a giant decentralised network of computers that spans the globe. In fact this network is more powerful than the most powerful supercomputers in the world. But the thing about such a network of computers is, that it takes a lot of electricity to run it. Right now Bitcoin miners are using about about as much electricity, as the country of Chile. Bitcoin mining has gone from zero, to 0.31 percent of the total world electricity consumption in less than ten years. Currently, one Bitcoin transaction consumes approximately 1012 KiloWatthours of electrical energy, or the equivalent of 34 U.S. households power consumption for one day. What to make of this?
These numbers may be seen as impressive, demonstrating the huge size and computing power of the Bitcoin network, but the electricity consumption can also be seen as a form of madness. Do we really need to spend this much energy to run a digital peer-to-peer monetary system with no trusted third parties, or could this be done in a more energy efficient manner? Well, it probably could be done, but should it be done? What could be the justification for a Proof of Work system, that spends such vast quantities of electricity? Answer: to catalyse innovation in power production, energy storage, and electricity generation.
In Bitcoin mining, which is the process by which transactions are verified and added to the public ledger, and also the means through which new bitcoins are created, the miners compete against in solving a difficult cryptographic puzzle. This takes a lot of electricity, and thus the profit of the miners depends on how much they have to pay for that electricity. And the price of that electricity depends on how effectively it is produced. So this theoretically gives the miners an incentive to solve the key problem facing humanity: the problem of energy. How do we get cheap energy for the growing human population, while transitioning from fossil fuels to renewable energy sources? Bitcoin mining incentivises the optimisation of energy gathering and electric power generating systems.
Bitcoin Mining Hardware
When it comes to Bitcoin mining hardware, laptops and PCs have been out-compteded by ASICs, or Application Specific Integrated Circuits. Ultimately the success of these specifically designed computers is based on the fact that they are more energy efficient than graphics cards or cpus in solving the cryptographic puzzles.
Not only the hardware of mining, but also the energy sources and electricity production methods have developed: miners have set up operations in places like Iceland, where cheap geothermal energy and free cooling arctic air is available. Bitcoin miners in China are using hydropower plants in Tibet, to utilise the potential energy of water streaming down hill from the Himalayas. In Russia, companies are selling Bitcoin miners as heaters, which help consumers cut their heating bill in the cold winter. In the future, how will the ingenious and entrepreneurial human minds, incentivised by competition and monetary rewards, solve the questions of energy gathering, energy storage, electric power generation and – and this is what I’m especially interested in – energy recycling – involved in Bitcoin mining?
Energy Recycling – Stirling Engine
Let us entertain some futuristic ideas and sketch a vision for the future of energy systems and the role of Bitcoin mining in them. As I began seriously thinking about this problem during this past spring, my mind focused on one key issue. Bitcoin mining generates a lot of heat, and energy needs to be used to cool the machines. Thus cold climates are preferable, because the amount of energy needed for cooling the machines will be lower.
Having lived most of my life in the cold Nordic country of Finland, I began to think how the cold winter could be utilised in Bitcoin mining. This led me to discover the Stirling Engine, which converts a temperature differential in to mechanical work.
What intrigued me the most about this engine, was the fact that it operated based on a temperature differential. I was fascinated by youtube videos, showing a small toy version of the engine working in room temperature, using nothing but ice as “fuel”.
Optimising Bitcoin Mining
So, the idea for an optimal BTC mining system started to form in my mind. Instead of having to use energy to cool the mining computers, we could use the abundantly available snow and ice in Finland, but in addition to that advantage we could take the waste heat from the mining computers, and use the temperature differential to create electricity with a Stirling engine. This electricity could then be fed back to the mining computers, creating an infinite loop of energy. In designing such a system, many practical engineering problems would have to be solved, and those engineering issues might be a good topic for a further article, but for now let us discuss the idea on a theoretical level.
So, to find out whether this idea is viable, we should try to find out the energy efficiency of such a system. The maximum theoretical efficiency of a Stirling engine is defined by the Carnot cycle, named by the French physicist Sadi Carnot, and is expressed by the formula:
Efficiency = 1-(Temperature(cold)/Temperature(hot))
Meaning, that the lower the cold temperature, and the higher the high temperature, the more efficient the engine will be. The way to approach total efficiency of 1, is to either get the cold temperature to absolute zero, or the hot temperature in to infinity.
So, let’s say we get 80 celsius heat from the miners, and -30 celsius heat from the ambient cold weather during the winter. We’ll have to translate the temperatures in to Kelvins, and thus we’ll get a theoretical efficiency for the engine, which is:
1-(243/353)=0.3116, or about 31% efficiency.
So, from 1 unit of energy we’ll be able to recycle 0.3116 units, and from that we can recycle 31 percent again, and again ad infinitum. This means, that the total efficiency of the system can be calculated as an infinite geometric sum, where ratio r is the efficiency of the system in capturing heat from the miners and turning it back in to electricity with, and a1 is the initial energy fed in to the system.
Infinite Geometric Sum = a1/(1-r)
Now, in this case, we can use the value “1”, for a1, meaning 1 unit of energy, and for r, we’ll use the efficiency of our Stirling engine. When we put this efficiency in to the formula for an infinite geometric sum, we’ll get
1/(1-0.3116) = 1.452674897.
This means that of the 1 unit of electrical energy put in to Bitcoin mining, we can theoretically recycle 45%, and use again for more mining. If we increase the temperature difference, for example by using liquid nitrogen to cool the cold side of the stirling engine, or burning biogas to heat the hot side, we can reach a much larger theoretical efficiency for the recycling process. And, purely theoretically speaking, the closer that efficiency gets to 1, the closer the amount of work we can do with a single unit of energy gets to infinity, as the same energy does work over and over again. Currently these kinds of efficiencies are not realistic, since there’s friction, and other such losses which lower efficiency. We have to assume though, that our ability to design these heat energy recycling, electricity generating systems will keep on improving.
Stirling Engine Properties
But let’s look at some of the properties of the Stirling engine, which make it so promising for many applications in increasing energy efficiency. Because the Stirling engine uses an external heat source, it can use any fuel, any heat source, and, if the heat energy is first stored in some medium, even many different fuels at the same time. This makes many available energy sources viable for utilisation simultaneously. An optimal energy system could utilise all the energy on a given piece of land: geothermal, solar, biomass, biogas, waste heat, or anything else. Likewise any source of cold can be used, from cold water, to ice, to cold air, to liquid air, or liquid nitrogen.
So, with this kind of a system, a Bitcoin miner could utilise all the energy available at his mining property: the heat from the sun in the summer, the geothermal heat of the ground, and the chemically stored energy in the biomass of his land. This could mean wood, special crops grown for fuel, wood-waste from industrial use of wood, and agricultural waste. Such a facility would be self-sufficient and sustainable when it comes to it’s energy and electricity needs, but it could also produce food locally, even all year round, in in-door greenhouses utilising automated vertical hydroponic or aeroponic farming.
Energy Gathering and Storing
The important thing is the energy gathering and storing, the capacity to convert that energy in to electrical power, and the ability to recycle that energy back in to electricity. Should it become more profitable to use more energy on growing a specific crop, or in some specific industrial activity, or simply selling energy in to the grid, than using it on Bitcoin mining, it could be done easily.
These kinds of power plants, factories, mining operations, farms, or really what we are talking about is sustainable and self-sufficient off-the-grid villages could pop up all around the world, and they could harness the energy of the sun, the geothermal energy inside the earth, the biological waste that is produced by human and animal life, and the waste heat from their cryptocurrency mining, or any other industrial processes, which could be anything from producing liquid nitrogen, to baking bread or making craft beer.
A globally connected, decentralised network of these kinds of energy systems, self-sustainable cryptocurrency mining eco-villages, could function as a launching platform for the Holy Grail of energy gathering. Giant rockets could be launched, accelerating directly towards the sun from the earth, then opening their massive sun-sails, slowly slowing down, getting as close to the sun as possible, in order to gather as much energy from the sun as possible, and then slowly return back home to earth with that most precious of cargo: pure energy.
Eventually we will build a so-called “dyson-sphere” around the sun, capturing all it’s energy to power our expansion throughout the Milky Way, and then beyond it to other galaxies.