Geothermal Power

The geothermal power system beneath Horizon City represents both the origin story of the city and a testament to Benjiro Takahashi's visionary genius. What began as an ambitious renewable energy project with no market for its excess power became the foundation for Benjiro's revolutionary concept: a vertical city with multiple levels, all powered by the energy drawn from the Earth itself. This vision transformed what might have been a failed investment into the eighth wonder of the world—a self-contained, self-powered metropolis that would redefine urban living.

Technical Overview

The geothermal power system operates on a relatively simple principle, as explained by Jack, a ToxPower technician:

"They drilled a quarter mile into the rock and installed high-temperature pipes leading to tanks at the bottom made from a proprietary meta-material comprised of titanium, tantalum, nickel, and tungsten. The idea was you could pump in water, and when it reached the bottom, it would flash to steam, which would power those turbines."

This closed-loop system consists of several key components:

1. Deep Thermal Wells: Quarter-mile deep shafts drilled into natural thermal vents
2. High-Temperature Pipes: Constructed from proprietary meta-materials capable of withstanding extreme heat
3. Steam Turbines: Massive 30-foot tall turbines that convert steam pressure into electrical energy
4. Water Pumps: Self-powered pumps that maintain the water cycle
5. Storage Tanks: Enormous containers for the cooled water before it returns to the thermal wells

The system is designed to be self-sustaining, with the energy generated by the steam powering the pumps that keep the water flowing. Power output can be regulated by adjusting the speed of the water pumps, allowing for flexible energy production based on demand.

Historical Development

The geothermal power plant was established in 2038, predating Horizon City by eight years. As Jack explains:

"The site was initially a geothermal power plant in 2038, trying to take advantage of the natural thermal vents in the area."

The initial investment of 10 billion yen came from a small group of investors, including Jules Hope, who would later become one of the founders of Horizon City. The plant was designed to capitalize on the unusually active thermal vents in the region, which promised to provide virtually unlimited clean energy.

However, the project soon encountered a fundamental problem: there was no market for the excess energy being produced. The remote location made power transmission to existing population centers prohibitively expensive, and without customers, the massive investment seemed destined to become a financial disaster.

This crisis of purpose led to an innovative solution that originated with Benjiro Takahashi. As he explained to Akina in their first meaningful conversation:

"Not many domes, one! One city sized dome, four cities tall, stacked on top of each other! All sharing infrastructure, all of it connected, all of it powered by the energy in the ground! Forever!"

Benjiro's vision was revolutionary—instead of a traditional city with sprawling horizontal development, he proposed a vertical metropolis with multiple levels, all powered by the geothermal energy that was already being produced in excess. This would solve two problems simultaneously: creating a market for the excess energy and maximizing land use efficiency.

The key technological breakthrough that made this vision possible was Benjiro's development of programmable metamaterials. As he explained:

"Programmable metamaterial. The structure doesn't have to be able to withstand the stresses all the time, so it can store that energy up like a battery, and when shear stresses are applied... it will actually heal itself."

This self-healing property allowed for architectural designs that would have been impossible with conventional materials, enabling the construction of a city-sized dome with multiple vertical levels.

What began as a 10 billion yen investment by two people expanded into a multi-trillion yen international consortium as Benjiro's vision of Horizon City took shape. The geothermal plant, originally conceived as an end in itself, became the foundation for a much grander project—a self-contained, self-powered city that would represent the pinnacle of human engineering achievement.

The Cooling Problem

Despite its initial promise, the geothermal system revealed a fundamental flaw over time: the thermal vents were cooling faster than they could naturally replenish. As Jack explains:

"As the city grew, ToxPower did its best to scale with the growing demand for power. They tapped more rock, but they had initially chosen the hottest location, and each additional turbine yielded less and less as they moved outward from the prime spot. It wasn't until twenty years in they realized the site was cooling too. They were sucking more heat out than was being put back in. It's down about fourteen percent now from where we started and losing half a percent each year."

This gradual decline in efficiency created an existential threat to Horizon City. The entire justification for the city's existence—to consume the power generated by the plant—was undermined by the plant's inability to meet the growing demand. This crisis ultimately led to the development of Feynman Batteries as an alternative energy source, though this solution was kept hidden from the public.

Engineering Innovations

Despite its ultimate limitations, the geothermal plant drove significant technological advancement. The need to contain and channel extreme heat led to the development of specialized meta-materials for the pipes and tanks. These materials, based on Benjiro Takahashi's programmable metamaterials, could withstand temperatures that would melt conventional metals.

The plant also pioneered advanced turbine designs that maximized energy extraction from steam, as well as self-regulating pump systems that maintained optimal flow rates without external control. These innovations found applications beyond power generation, contributing to Horizon City's infrastructure and ToxPower's diversification into materials science.

As Jack notes:

"ToxPower is first and foremost an engineering company that sells power as one of its products. We've made more from our meta-materials division in recent years than we have in selling power."

This pivot from energy production to materials science and engineering represents ToxPower's adaptation to the limitations of its original business model—a pattern that would repeat with the development of Feynman Batteries.

Current Status

Today, the geothermal system continues to operate beneath Red Level, though at significantly reduced capacity. It has lost approximately 14% of its original output and continues to decline at a rate of 0.5% per year. While still functional, it has been largely supplemented by the secret Feynman Batteries, which provide the bulk of Horizon City's power.

The massive infrastructure of turbines, pipes, and pumps occupies a significant portion of the space beneath Red Level, which is why Red Level has less vertical space than the other levels of Horizon City. As noted in "Weapon":

"ToxPower, at least the bulk of it, was located under the Red level. The other levels in Horizon City had ample vertical space with high-rise towers, but Red level was almost a fifth of the vertical space due to it being built on top of the power plant that was the lifeblood of the city."

This physical constraint has shaped the development of Red Level, contributing to its crowded, industrial character compared to the more spacious upper levels.

Public Perception vs. Reality

For most citizens of Horizon City, the geothermal plant represents the city's commitment to renewable energy and self-sufficiency. The public narrative celebrates the ingenuity of harnessing natural thermal energy and the engineering prowess that made Horizon City possible.

What remains hidden is the plant's gradual failure and the desperate measures taken to compensate for it. The development of Feynman Batteries—with their potentially catastrophic risks—was a direct response to the limitations of geothermal power, yet citizens remain unaware of this transition.

This gap between public perception and reality exemplifies the broader pattern of secrecy and control that characterizes Horizon City's governance. The geothermal plant, once a symbol of sustainable innovation, has become part of an elaborate deception maintained by ToxPower and the Horizon City Board.

Legacy and Symbolism

The geothermal power plant embodies the origin story of Horizon City—a tale of visionary genius, technological innovation, and human adaptation. What began as Benjiro Takahashi's ambitious concept of a vertical city powered by the Earth's natural energy evolved into a marvel of engineering that redefined urban living.

The initial vision was revolutionary: "One city sized dome, four cities tall, stacked on top of each other! All sharing infrastructure, all of it connected, all of it powered by the energy in the ground! Forever!" This dream represented the pinnacle of sustainable design—a self-contained ecosystem that would harness natural energy to support human civilization indefinitely.

However, the cooling of the thermal vents revealed the limitations of even the most brilliant visions when confronted with physical reality. This challenge led to further innovation in the form of Feynman Batteries, demonstrating both the ingenuity and the potential dangers of pushing technological boundaries.

In this sense, the geothermal plant is not merely a technology but a symbol of Horizon City itself—born from visionary genius, made possible by revolutionary materials science, and ultimately revealing both the promise and the limitations of human ambition. The gap between Benjiro's original vision of eternal geothermal power and the reality of depleting thermal vents mirrors the broader themes of Horizon City: the tension between idealistic visions and practical realities, and the lengths to which humanity will go to maintain its technological achievements.