---
title: Fusion's Next Test Is an Engineering Queue That Runs Four to Six Years
description: Commonwealth Fusion Systems filed to connect its first ARC plant to PJM in April 2026, the first fusion developer to enter a major US grid queue.
author: Darie Nani (Editor-in-Chief)
updated: 2026-07-30T11:30:55.117Z
canonical: https://www.sovereignmagazine.com/article/commonwealth-fusion-pjm-grid-queue-arc
image: https://cdn.nanimediahouse.com/cfs-devens-campus-aerial-69896.webp
categories: Green Tech
content_type: News
region: United States
publication: Sovereign Magazine
schema_type: Article
---

Commonwealth Fusion Systems submitted a generation interconnection request to PJM Interconnection in April 2026, becoming the first fusion power plant developer to ask a major American grid operator for a place on the system. The request starts a series of engineering studies that, on the company's own account, can run four to six years from the start of the study process to the point where electricity is generated.

The application puts the company's first ARC plant, at the Fall Line Fusion Power Station in Chesterfield County, Virginia, through the same process as any other generator. PJM serves about 182,000 megawatts of capacity across 13 states and the District of Columbia, to more than 65 million customers, and about 1,400 generators are already interconnected on its system. ARC is designed to add 400 megawatts.

## The Site, the Permit and the Customers Came First

Before it applied, CFS had chosen the Virginia site, secured a joint development agreement with Dominion Energy, obtained a conditional use permit, and sold the output. Google and Eni, both investors in the company, signed [power purchase agreements](https://www.sovereignmagazine.com/article/meta-s-nuclear-power-play-sets-the-standard-for-ai-s-energy-future) to buy more than half the power the plant will produce, and Google, the first customer, will take half. Dominion advised CFS on navigating PJM's interconnection process under the joint development agreement.

To file the request, CFS had to specify not only the fusion machine but the power delivery side of the plant, including the steam, turbine and generating systems. Ben Byboth, the company's director of power business development and strategy, wrote that submitting it was “one of the long-lead actions that anyone needs to take to truly be serious about providing power in the early 2030s.”

## PJM Studies New Projects in Groups, Not One at a Time

An interconnection application starts engineering studies that test whether the grid can carry the new capacity safely and reliably. Projects are studied as a single group of changes, so PJM can work out which system upgrades the whole batch requires. CFS filed into what it calls PJM's reformed interconnection process, a system meant to speed connections up.

Byboth wrote that PJM will need 66 gigawatts of new power for summertime peak use by 2036, which he put at more than 160 ARC plants' worth of output.

## SPARC Still Has to Show Net Energy

The plant in Virginia depends on a machine in Massachusetts. CFS is finalizing assembly of SPARC, its demonstration machine at its Devens headquarters, whose job is to demonstrate net fusion energy, a milestone the company calls Q>1. SPARC will not generate electricity. That waits for ARC.

The company has posted checkpoints along the way. The US Department of Energy validated its completion of a magnet technology performance test in September 2025. In June 2026 CFS published five peer-reviewed papers on the physics of the ARC power plant, and in July 2026 it was named the first international partner in the UK Atomic Energy Authority's LIBRTI program.

> "In the 2030s, we will put commercial fusion on the grid."
> — Bob Mumgaard, Chief Executive Officer and Co-founder, Commonwealth Fusion Systems

## Four Billion Dollars Behind a Machine Still in Assembly

CFS said on 30 July that it had raised $1 billion in additional equity financing, taking the total raised since its founding in 2018 to $4 billion. The company says that is about 30 percent of all the capital raised by the fusion industry so far, and that the round is the largest single raise by a fusion company since its own $1.8 billion Series B in 2021. It raised $863 million last year.

The investor list now runs to pension funds, sovereign wealth funds, infrastructure investors and industrial corporate partners. CFS says its approach rests on decades of experience and more than 150 tokamaks constructed to date.

More on the company's fusion program is at [cfs.energy](https://cfs.energy).

## FAQ

**Q: How does the PJM interconnection queue work?**
A new generator files an interconnection request, which starts engineering studies checking whether the grid can carry the added capacity safely and reliably. PJM studies projects as a single group of changes rather than one at a time, so it can determine the system upgrades the whole group requires.

**Q: How long does a grid interconnection take?**
Ben Byboth, CFS's director of power business development and strategy, has written that from the start of the study process to the generation of electricity, the process can take four to six years.

**Q: When does CFS say fusion power will reach the grid?**
The company's stated target is the early 2030s for its first plant, ARC, planned for the Fall Line Fusion Power Station in Chesterfield County, Virginia. Its interconnection request went to PJM in April 2026, and the studies that follow can run four to six years.