EarthGrid™ Plasma Tunnel-Boring Technology 

Challenges in the Power Grid:

The United State’s current power grid infrastructure is grappling with the challenges of transitioning to renewable energy sources. The American Society of Civil Engineers (ASCE) rates the current infrastructure at a concerning grade of C-, with ratings typically in the D range. This underperformance, coupled with the abandonment of 80% of proposed solar and wind projects due to congestion and lack of transmission infrastructure, underscores the urgent need for innovation. EarthGrid proposes the deployment of plasma tunnel boring robots as a viable solution to underground utility lines quickly and less expensively. These robots promise speeds up to 100 times faster and cost reductions of up to 90% compared to traditional tunnel boring methods. 

Plasma Tunnel Boring Technology:

To comprehend the innovation behind EarthGrid’s technology, it is essential to delve into the mechanics of tunnel boring. Traditional methods involve the use of mechanical drills, but EarthGrid’s approach employs torches powered by plasma created from electricity and airflow. This plasma, with temperatures ranging from 10,832 to 18,033 degrees Fahrenheit, enables the machines to bore rapidly through various geological formations via vaporization and spallation. 

The machines’ ability to operate at depths ranging from 10 to 100 feet below the surface is a key advantage, allowing them to navigate beneath the existing maze of underground utilities. The plasma torches’ efficiency in vaporizing materials ensures continuous progress, even when encountering challenging terrains like clay, where traditional methods might face delays. 

Advantages of Plasma Boring:

The speed and cost-effectiveness of EarthGrid’s plasma drilling technology stem from its adaptability to diverse geologies without slowing down. Conventional methods can experience delays when confronted with different terrains, leading to increased project timelines and costs. EarthGrid’s plasma torches, however, boast the capability to bore through various materials seamlessly. 

The cost-effectiveness of EarthGrid’s technology is further exemplified by lower operating costs compared to traditional methods. There is no need for frequent changes of drill bits and cutter heads, resulting in reduced downtime. The incorporation of robotics minimizes the need for a large workforce, and the absence of drilling mud and chemicals simplifies the waste disposal process. 

Addressing Safety and Environmental Concerns:

One notable concern surrounding plasma drilling is the extreme heat generated by the process. However, EarthGrid has implemented sophisticated measures to manage this heat effectively. Ground-penetrating radar is employed to meticulously map the underground infrastructure, ensuring that the plasma torches avoid existing utilities and structures. 

The heat generated during plasma drilling dissipates through a phase change when the rock melts, resulting in tunnel walls that maintain temperatures between 50-70 degrees Celsius. This is crucial, as it ensures that the heat is not intense enough to melt pipes or significantly impact the surrounding environment. Furthermore, the utilization of a vacuum removal system and air jets helps dissipate the heat efficiently, minimizing its impact on the surrounding areas. 

Approximately 35% of the energy converted into heat during the process is absorbed by the water from the torque’s body, and another percentage is transferred into the rock. To address the rest, EarthGrid incorporates a concrete/shotcrete mixture specifically designed to work with heated walls, further contributing to the overall efficiency of the process. 

Versatility Across Geologies:

EarthGrid’s plasma drilling technology has undergone extensive testing across a variety of geological conditions, showcasing its adaptability and efficiency. Notably, the technology has demonstrated exceptional speed, surpassing traditional boring techniques, especially when dealing with challenging rocks like basalt. 

In instances where the drilling encounters soil, such as glacial fill-ins, EarthGrid’s technology proves its versatility. The rapid vaporization of organics leaves a crust that can be managed through additional construction techniques, such as shotcreting the tunnel walls. The technology has been successfully tested in wet soil, mixed surfaces, and soil with natural gas injections. 

Innovative Business Models:

EarthGrid introduces two innovative business models—BOOM (Build, Own, Operate & Maintain) and BADASS (Boring And Drilling As a Simple Service)—providing clients with flexibility in project engagement. The BOOM model allows EarthGrid to build the tunnel, which clients can then own and lease to power companies, covering permitting and financing. In contrast, the BADASS model involves EarthGrid building the tunnel and clients paying per cubic meter, essentially subscribing to a Boring As A Service (BAAS) model. 

This level of flexibility in business models adds a layer of customization to suit the unique needs of different projects. The models not only facilitate the construction of tunnels but also offer options for long-term partnerships and revenue-sharing arrangements. 

Regulatory Approvals and Expansion Plans:

EarthGrid’s strategic approach includes obtaining utility status and a Certificate of Public Convenience and Necessity (CPCN) in 37 states, with plans for further expansion. This strategic positioning enhances the likelihood of obtaining Right of Way (ROW) permits, a critical component for projects involving underground conduits and utility lines. 

The utility status and CPCN empower EarthGrid in negotiations with state departments of transportation (DOT), such as Caltrans, for favorable considerations in ROW access. This advantage becomes particularly crucial when navigating the complex web of regulations associated with underground construction beneath public roads.

As EarthGrid expands its reach, plans are in place to deploy lines underneath basalt formations for offshore wind and solar projects. Additionally, the vision extends to building an inter-continental supergrid, connecting North America to Europe through high-voltage DC powerlines. Partnerships and Memorandums of Understanding (MOU), such as the one with SOO Green, further solidify EarthGrid’s position in the evolving landscape of renewable energy infrastructure. 

Infrastructure Reinforcement and Power Consumption:

Concerns related to seismic activity and power consumption are integral considerations in EarthGrid’s approach. Collaborating with partners, the company ensures the design of appropriate tunnel linings to withstand seismic events while maintaining operational efficiency.

The significant power requirements of plasma drilling are addressed through meticulous planning and mobile substations. Traditional tunnel boring methods, which are slower, use approximately 20MW of power. EarthGrid employs mobile substations connected to transmission lines, with 3-5 trucks transporting switchgear and transformers to the site. The choice of a 21kv power supply for smaller machines and 69kv or higher for larger machines optimizes power delivery, and unspooling cables for resplicing is a testament to EarthGrid’s commitment to operational efficiency. 

Depth Challenges and Cityscapes:

The unique challenges presented by cityscapes, including the depth of storm sewers and the unpredictability of municipal infrastructure, necessitate nimble solutions. Municipalities often lack accurate records of storm sewer locations, making it challenging to plan around these obstacles. EarthGrid addresses this challenge through the use of ArcGIS solutions for co-location, effectively mapping the underground landscape. 

City challenges also include the ability to navigate beneath buildings and structures without causing disruptions. EarthGrid’s plasma drilling technology proves to be more nimble in terms of turning radius, with a range of 6-8 meters, allowing it to maneuver through tight spaces in urban environments. 

Personnel Safety and Environmental Monitoring:

Safety is a paramount concern during tunnel-boring operations. EarthGrid implements strict safety measures, prohibiting any personnel from entering the tunnel while the tunnel-boring robot is in operation. Access is provided through vertical shafts, ensuring a safe entry point for maintenance and emergency situations. 

The use of electric carts for maintenance purposes minimizes the need for human presence within the tunnel during operations. Additionally, noxious gases generated during the plasma drilling process are continuously monitored to safeguard personnel health and well-being. 

Infrastructure Access and Shaft Design:

Addressing concerns about access and manholes, EarthGrid adopts a unique approach. Instead of traditional manholes, the company utilizes shafts strategically placed every couple of miles along the tunnel. These shafts serve multiple purposes, including providing access for maintenance personnel, ventilation, and emergency exits. 

Access shafts are equipped with climbing ladders, safety harnesses, and ventilation systems to ensure the safety and well-being of personnel. Larger access shafts, especially in long tunnels, may feature elevators with slanted ramps, accommodating electric carts traveling at speeds of 25-40 mph. Alternatively, tracks with rails can facilitate the movement of a mini-train, transporting supplies efficiently. 

Waste Management and Environmental Impact:

One significant advantage of plasma drilling over traditional methods is its eco-friendly approach to waste management. Unlike horizontal directional drilling (HDD), which utilizes lubricants and generates wastewater, plasma drilling produces spoils consisting solely of rock. This eliminates the need for expensive wastewater transport and presents an opportunity to reuse the rock. 

The repurposing of spoils into sand for shotcrete and concrete mixtures contributes to the construction industry, providing a sustainable solution for road and infrastructure development. The absence of harmful drilling chemicals further minimizes the environmental impact, aligning with EarthGrid’s commitment to responsible and sustainable construction practices.