We started Petra because we believe the world is safer when utilities are underground. For years, I watched the electrical grid in my home state of California crumble under the pressure of natural disasters. Every fire season in Northern California, we experience rolling blackouts because overhead electrical lines might start fires. So much so that it has become policy to shut off power where utility lines might spark. Texas A&M came out with a report that power lines have caused more than 4000 fires in Texas in the past few years. As I studied the problems facing our utility infrastructure, there was a clear need for overhead electrical lines in fire-prone areas to be placed underground and for our aging water and sewer infrastructure to be rapidly upgraded.
Upon connecting with my co-founder Shivani Tores, we decided that Petra would initially focus on undergrounding electrical lines to reduce the impact of wildfires and storms on lives and property. Our long-term mission was to change the economics of how all utilities were buried underground to make our infrastructure more resilient. Traditional boring methods for utility tunnels are astronomically expensive and arduous because of one simple fact: geology changes, and we haven't had modern tools capable of boring through all types of geology.
The most significant risk for underground contractors is encountering ground conditions they could not anticipate previously. For example, when civil engineers plan the routes for underground conduits, they get borehole samples every hundred or so feet and then produce a report that informs the construction team what type of geology they will encounter. Based on this geological report, the construction and engineering groups will choose a boring machine. But the resolution on these reports is too coarse: sometimes, between 100-ft samples, there are often clay seems or cobbles or other ground conditions that they didn't sample and therefore, didn’t anticipate. If you get this wrong, you often also have chosen the wrong boring machine. And if you chose the wrong boring machine and encounter a nightmare geology, you have a high risk of your machine getting stuck in the ground.
Soft soil changes to the ground with cobblestones which vary to hard rock; there has been no single method that can bore through all geologies at small diameters. This is such a problem that many construction companies append a 30% markup, called a contingency fee, on their jobs for the what-if scenario they hit geology that they cannot anticipate.
On both longer pipeline jobs, this is a huge problem because you run the risk of encountering more types of geologies, especially nightmare ones. But on short haul boring projects it’s also a risky problem because contractors don’t want to run the risk of losing their machine in the ground! It makes sense: why would a contractor jeopardize their expensive - sometimes multi-million dollar equipment - on a short haul job if they run the risk of losing it underground. The opportunity costs of their machinery getting stuck and not earning money on new jobs is too great.
We want to remove the risk from undergrounding jobs and we’re doing this by focusing on building technologies that can bore through all geologies, especially nightmare geologies.
We’re starting first with hard rock. We’ve developed the world’s first non-contact hard rock cutterhead that can bore utility tunnels quickly through previously impenetrable rock (like 44K PSI Sioux Quartzite) using a process called thermal spallation. We thermally shock the rock in a controlled way by blasting it with 1000+ mph of mass flow and heat to break up the rock into tiny little pieces that are then evacuated out of the tunnel using our proprietary spoils removal system. We have developed 10 novel subsystems to support our new cutterhead.
Boring hard rock 60" and below has not been possible—until now. This lack of technical capability has stymied utility providers working in hard rock geologies. Petra's tunneling robot bores through the hardest, most abrasive ground conditions on earth, and it is the first of its kind. Our hard rock method is the 0 to 1 improvement in the industry; it's the thing that no one else can do.
The harder the rock, the more conventional methods struggle. In contrast, Petra is designed for the toughest, nightmare geologies, and we're just getting started.
The US national grid, established more than 40 years ago, wasn't built to withstand climate change or new strains on the system. Without a new approach, the stresses will only get worse. The Energy Information Administration (EIA) projects global energy demand will increase by 50% in the next 30 years, requiring more transmission lines - if we want a resilient infrastructure, power lines must be undergrounded.
Furthermore, we need to increase the number of new utility tunnel installations for water and sewer. There are 240,000 water main breaks a year due to our aging infrastructure in the US. Coastal communities need new sewage lines to replace old septic tanks because rising sea waters are causing them to fail and seep into the ground and pollute waterways. In the future, we will need to bury more fiber bundles to keep up with our data demands, requiring wider diameter conduits, which should be underground if we want to make our communications infrastructure more resilient. And new utilities like green hydrogen are likely going to need new pipes too. In other words, all critical infrastructure is going to have to be undergrounded if we want to keep communities lit, connected and safe.
Petra is the only company solely focused on building new technologies to underground our critical infrastructure at scale.
