○Power Generation and Storage
Power generation and storage should be both sustainable and structurally simple. Therefore, electricity will be generated from the sea, rivers, and land, and shared collectively. This way, life can be sustained entirely through natural energy without the use of depletable resources.
Since Prout Village is not a monetary society, there is no economic activity, and thus no daily massive consumption of electricity driven by competition. With the elimination of economic activity, the amount of electricity required is drastically reduced, leading to a significant decrease in carbon dioxide emissions and serving as a powerful countermeasure against global warming. Prout Village prioritizes the following combination of power systems.
The primary source of electricity is magnesium batteries, developed by Professor Takashi Yabe of the Tokyo Institute of Technology. These batteries consist of thin magnesium plates that can be stored and transported. Electricity is generated by placing magnesium on the negative side and carbon-based material on the positive side, immersed in saltwater.
This battery delivers over 8.5 times the energy of lithium-ion batteries commonly used in smartphones, with a much lower risk of ignition compared to hydrogen fuel. Conventional batteries can power drones for only 30 minutes, but this magnesium battery can keep them flying for two hours. It can also run a golf cart for approximately two hours.
Magnesium is abundantly present in seawater—about 1,800 trillion tons—equivalent to 100,000 years' worth of the current global annual petroleum consumption (10 billion tons). The risk of depletion is extremely low, and it can be utilized globally. After use, the resulting magnesium oxide can be heated above 1,000°C to regenerate magnesium, allowing the battery to be reused.
The same professor has also developed a system that focuses sunlight using mirrors—without electricity—into a laser beam, which then shines on magnesium oxide to separate the oxygen and regenerate usable magnesium. Additionally, he developed a desalination device that extracts both magnesium and salt from seawater.
The magnesium battery used in the experiment measured 16.3 cm in width, 23.7 cm in depth, and 9.7 cm in height. Once water was added, it weighed about 2 kg and produced a maximum output of 250W—enough to power a 450L refrigerator for one hour. By connecting five or ten units, it is possible to supply power to larger equipment. A car equipped with 16 kg of magnesium batteries can travel approximately 500 km.
When seawater is desalinated, both salt and bittern (magnesium chloride) remain. When laser light is applied to this magnesium chloride, magnesium is produced. It is also claimed that magnesium is abundant in desert sand. From 10 tons of seawater, 13 kg of magnesium can be extracted, which corresponds to the electricity consumption of a standard household for one month.
By making magnesium batteries the foundation of daily life, they can be produced from oceans around the world. The risk of depletion is low, they can be stored and transported, and electricity can be used even in remote or harsh environments.
The desalination devices used to produce magnesium require electricity. To supply that electricity, small hydropower generation systems will be established along rivers and streams worldwide. The amount of electricity generated depends on the drop height and water volume. In Japan, for example, the Itoshiro Banba Seiryu Power Plant in Gifu Prefecture generates 125 kW of electricity—enough for approximately 150 households—with just one water wheel utilizing a 111-meter drop.
In addition to small hydropower generation, tidal current generation in seas and rivers will also be utilized. Since ocean waves are in constant motion, tidal current generation can provide a stable electricity supply regardless of day or night. Moreover, its structural simplicity eliminates the need for large-scale facilities, which is a major advantage.
If small to medium-sized wind power systems are added to this, additional power can be generated when the wind is blowing. Various types of wind turbines have been developed, and vertical-axis wind turbines—which rotate horizontally—are particularly suitable as they can harness wind from all directions. In Prout Village, the priority is to establish small- to medium-scale energy systems that each Municipality can manufacture and manage, producing decentralized energy. Therefore, large-scale wind turbines are not the top priority.
The magnesium batteries, small hydropower, tidal current, and wind power systems discussed so far do not emit carbon dioxide during electricity generation. They offer a stable and sustainable method of power generation and contribute to addressing global warming. In addition to these, other energy sources will also be used simultaneously to promote diversification of natural energy.
Furthermore, for electricity generation from sunlight, perovskite solar cells are being considered. These are Mid-tech, rare-metal-free, manufacturable via low-temperature processes, and with chemical treatment, the glass substrates allow almost all internal materials, such as iodine, to be recovered without significant waste.
Silicon-based solar cells, which became widespread in the 2000s, require large amounts of energy and scarce resources during manufacturing, and recycling at the end of their life cycle has many challenges. Therefore, they are not used, as they cannot be considered sustainable in the long term.
Using perovskite solar cells to generate electricity from sunlight, Prout Village installs simple support structures on farmland and places solar panels in the upper space. This agrivoltaic system allows agriculture to continue while moderately shading excessive sunlight, and simultaneously generates electricity.
The magnesium batteries, small hydropower, tidal current power, wind power, and perovskite solar cells described so far all emit no CO₂ or other greenhouse gases during electricity generation, contributing to climate change mitigation and providing stable and sustainable electricity.
In addition, other energy sources are used concurrently to diversify renewable energy sources.
One such source is vacuum-tube solar water heaters, which produce hot water from solar heat for use in baths and kitchens. These units integrate a heat collection section and a hot water storage tank. In Japan, temperatures reach 60–90°C in summer and around 40°C in winter.
Simultaneously, solar heat collection panels are also under consideration. These systems warm air inside the panels to about 50°C using solar heat, and then circulate the warm air through ducts to provide heating for the entire home.
Because these systems utilize solar heat, the orientation and angle at which the water heaters and collection panels are installed is crucial. In Japan, true south is most effective, delivering 100% efficiency; true east and true west can still yield around 80%. A roof angle of 20 to 30 degrees is ideal. These systems can be installed on rooftops or on the ground. When installed on rooftops, roof shapes should be designed to maximize collection surface area. Since solar water heaters and collection panels utilize heat as heat, their structures are simple.
For lighting and other needs in locations without power lines, plant-based power generation and ultra-small hydropower systems are also being considered. Plant-based electricity is generated by inserting two electrodes into the soil, which yields a weak current. However, the output is very small, producing about 1.5 volts from a single setup. In experiments where 100 units were connected, over 100 volts of household electricity was achieved. The optimal electrode pair is magnesium and binchotan charcoal, and no rare metals or underground resources are used.
Additionally, portable ultra-small hydropower devices approximately one meter in length have been developed. These can generate electricity from small streams with a height difference of just one meter, producing 5W with a water flow of 10 liters per second.
In Finland, sand batteries are also in use. These systems convert electricity generated from solar and wind power into heat, which is then stored in sand. An insulated tank, four meters wide and seven meters tall, holds 100 tons of sand. The heat is supplied to nearby areas and used for building heating and heated pools. Sand heated to over 500°C can store energy for several months. The system has a lifespan of several decades. As long as the sand is dry and free from flammable waste, any type of sand can be used, making this feasible in Japan as well.
In Finland, it is estimated that in order to provide heat for an area with 35,000 people, a storage tank 25 meters tall and 40 meters in diameter filled with sand would be necessary. Sand batteries are also structurally simple, consisting of pipes, valves, fans, and electric heaters, and construction costs are relatively low.
In the United States, sand batteries are also being developed. In these systems, silica sand is heated to 1,200°C and stored in an insulated concrete container. When converting the stored heat into electricity, the heat is used to boil water, generating steam that spins a turbine—a type of water wheel with multiple blades. This turbine is connected to a generator, which produces electricity. When converting heat to electricity, such equipment is required.
In addition to these, solid biomass is also used. This refers to solid fuel made by drying and compressing plant materials such as wood, rice straw, and weeds into pellets or briquettes. Burning these fuels generates heat or electricity. The system is simple and easy to maintain. While carbon dioxide is emitted during combustion, it is considered carbon neutral because the plants absorb carbon dioxide during their growth. Especially when unused local resources such as weeds are utilized, this becomes a highly sustainable and safe energy source.
These constitute the main methods of power generation and storage in Prout Village. They are either zero or carbon-neutral in emissions, do not rely on rare metals or depletable resources, and represent a decentralized model of energy production.
Main Methods of Power Generation and Storage in Prout Village
○Power‑Generation & Storage Methods Not Adopted in Prout Village
Below is a summary of existing technologies that Prout Village intentionally avoids, together with the key reasons.
Power Generation and Storage Methods Not Adopted
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