---
title: "Mazama Energy’s $135M: Series B, Grants, or Both?"
description: "Mazama announced $135 million of new capital on September 17, 2026, including an oversubscribed Series B led by Centaurus and Doerr Capital. Axios reports Series B funding and grants. Valuation was not disclosed. Newberry’s 331°C well is the proof; commercial power is not."
date: 2026-09-18T00:00:00.000Z
source: https://venturecapitaltracker.com/2026-mazama-energy-135m-series-b-superhot-geothermal
---

# Mazama Energy’s $135M: Series B, Grants, or Both?

> Mazama announced $135 million of new capital on September 17, 2026, including an oversubscribed Series B led by Centaurus and Doerr Capital. Axios reports Series B funding and grants. Valuation was not disclosed. Newberry’s 331°C well is the proof; commercial power is not.

**[Mazama Energy](/startup/mazama-energy)** announced **$135 million of new capital** on **September 17, 2026**, **including an oversubscribed Series B** led by **Centaurus Capital** (John Arnold) and **Doerr Capital**. [Khosla Ventures](/fund/khosla-ventures) and [Gates Frontier](/fund/gates-frontier) returned. ConocoPhillips and Shell Ventures joined. **Valuation was not disclosed.** [GlobeNewswire](https://www.globenewswire.com/news-release/2026/09/17/3364060/0/en/mazama-energy-raises-135-million-to-scale-the-world-s-hottest-engineered-geothermal-system.html) and [Canary Media](https://www.canarymedia.com/articles/geothermal/mazama-energy-raises-135m-oregon-geothermal) treat $135 million as a **bag that includes Series B**. [Axios](https://www.axios.com/pro/climate-deals/2026/09/17/mazama-energy-superhot-geothermal) says **Series B funding and grants**. [TechCrunch](https://techcrunch.com/2026/09/17/khosla-backed-mazama-energy-just-raised-135m-to-drill-deeper-into-super-hot-rock-geothermal/) called it a Series B. Do not flatten that into “$135 million of priced equity.”

Hottest disclosed EGS well, still pre-power. The money is to prove 15 MW horizontal wells — not to match [Fervo](/startup/fervo-energy)’s public offtake.

## Key facts

| Field | Detail |
| --- | --- |
| Company | [Mazama Energy](/startup/mazama-energy) ([mazamaenergy.com](https://mazamaenergy.com)) — Frisco/Dallas; Newberry, Oregon field |
| Amount | **$135M new capital** including Series B (company). Axios: **funding and grants** |
| Leads | Centaurus Capital, Doerr Capital. ** |
| Returning | [Khosla Ventures](/fund/khosla-ventures) (incubator), Gates Frontier |
| Strategics | ConocoPhillips, Shell Ventures |
| Also named | SiteGround Capital, H. Barton Asset Management, Rothschild Foundation |
| Technical print | 629°F / **331°C** EGS (2025); second well **10,350 ft** ~**80%** faster |
| Next | Project **Ceres** (DOE-supported): **15 MW**/well; power test **2027** |
| Company targets | **>10 GWe** Newberry resource (vs Khosla’s **5 GW** comment last year); **200 MW** first site by **2030** |
| Valuation / ARR / offtake $ | **Not disclosed** |

## What the wells actually show

Mazama is not selling steam from a natural aquifer. It fractures hot, dry rock and wants **supercritical** fluid around **750°F / 400°C**, which it says can deliver **up to 10×** conventional geothermal output per well. CEO Sriram Vasantharajan told Canary that superhot rock is “almost essential” for geothermal to compete with fossil fuels.

The 2025 Newberry well is a **temperature record**, not a PPA. Ceres is the commercial blueprint: horizontal wells, DOE support, drilling later this year, testing early next year. Rig time matters — Canary notes **>$100,000/day**. An 80% faster second well is the operating tell, if it holds at 15,000 feet.

## Mazama vs Fervo (and storage)

| | [Mazama](/startup/mazama-energy) | [Fervo](/startup/fervo-energy) | [Form Energy](/startup/form-energy) |
| --- | --- | --- | --- |
| Status | Private, pre-power | Public **FRVO**; sells power | Private; iron-air storage |
| Job | Superhot EGS at Newberry | EGS at cooler commercial temps | Multi-day batteries |
| Last print | **$135M bag**, Sep 2026 | IPO ~**$1.89B**, May 2026 | **$750M** Series G, Aug 2026 |

Same “firm clean watts for AI load” tape. Different product. Form stores; Mazama and Fervo try to **generate**. Fervo already cleared a public-market diligence bar Mazama has not.

Canary places **Sage Geosystems** (Texas pilot power) and **Quaise** (also Newberry; ~$180M in August, not covered here) on the same map. Do not treat those as Mazama closes.

## What is not proven

- Equity vs grant split inside **$135M**.
- Valuation, offtake, interconnection, or well cost at 400°C.
- Whether **10 GWe** resource potential becomes **200 MW** by 2030.
- Independent verification of “hottest EGS” beyond company/Khosla claims.

## Practical takeaway

- **Founders (geothermal):** Sell **well productivity and time-to-depth**, not terawatt TAM. Arnold’s quote is about innovation required — not a signed offtake.
- **Investors:** Diligence the **grant mix** and whether Ceres produces electrons, not just hotter rock.
- **Operators:** Relevant if you need **24/7** western U.S. clean supply and can wait past a 2027 demo.

### Sources

1. [GlobeNewswire — Mazama $135M](https://www.globenewswire.com/news-release/2026/09/17/3364060/0/en/mazama-energy-raises-135-million-to-scale-the-world-s-hottest-engineered-geothermal-system.html)
2. [TechCrunch](https://techcrunch.com/2026/09/17/khosla-backed-mazama-energy-just-raised-135m-to-drill-deeper-into-super-hot-rock-geothermal/)
3. [Canary Media](https://www.canarymedia.com/articles/geothermal/mazama-energy-raises-135m-oregon-geothermal)
4. [Axios Pro](https://www.axios.com/pro/climate-deals/2026/09/17/mazama-energy-superhot-geothermal)

**By:** [Venture Capital Tracker](https://venturecapitaltracker.com/editorial-policy)

**Editorial note:** AI tools assisted with research, structure, or drafting. Venture Capital Tracker retains human editorial responsibility for factual accuracy, relevance, and source quality before publication.