Heliogen

Cleantech / solarUSA

New to Unitard

📉 Public < $1B

Peak $2 BillionRecorded estimate

~-99%

from peak

🦄
Became a unicorn
2021
📈
Peak valuation
$2 Billion ’21
💔
Became a Unitard
2022
💸
Last valuation estimate
~$20M

Current status

Trades on the OTC market; agreed to be acquired by Zeo Energy in 2024

The rise & fall

7 moments · 2013–2024

The key moments, with employee sentiment along the way.

2013

Founded at Idealab

Bill Gross's concentrated-solar startup: fields of AI-steered mirrors focusing sunlight into extreme industrial heat.

Wikipedia

Nov 2019

Out of stealth with a Bill Gates halo

Announces mirror-field temperatures hot enough for industrial processes, with Gates among the backers.

CNBC

Dec 2021

The peak: a ~$2B SPAC listing$2B

Merges with Athena Technology Acquisition Corp and hits the NYSE at the crest of the cleantech-SPAC wave.

Reuters

2022–23

Commercialization stalls

The technology is slow to leave the test field, and the stock begins a roughly 99% slide.

Reuters

2022

Slips out of the club

Less than a year after listing, the market cap is under $1B.

Macrotrends

2022–24

From the inside · Glassdoor reviews, 2022–24

Glassdoor reviews from the slide described constant strategy churn — engineers said the company kept switching between receiver technologies without shipping a finished product — and traced repeated layoffs and leadership turnover after the founder's exit to eroding focus and morale.

2024

Zeo Energy absorbs what's left

After the ~99% collapse pushed the shares onto the OTC market at a roughly $15M micro-cap, Heliogen agrees to merge with Zeo Energy at a tiny valuation.

Reuters

💬 entries paraphrase anonymous, unverified reviews posted publicly on Glassdoor ↗; dated facts carry their source.

How it happened

Heliogen was a Bill Gates-backed cleantech startup using fields of AI-controlled mirrors to concentrate sunlight to extreme temperatures for industrial heat and green hydrogen. It went public on the NYSE in late 2021 via a roughly $2B SPAC merger, but its technology was slow to commercialize and the stock collapsed about 99% onto the OTC market before Zeo Energy absorbed it in 2024.

Source: Reuters / BizTimes / stockanalysis (Bill Gates-backed concentrated-solar-power startup; went public via a ~$2B SPAC merger with Athena Technology Acquisition Corp in late 2021; technology and commercialization stalled, the stock collapsed ~99% and was pushed to the OTC market; agreed to merge with Zeo Energy in 2024 at a tiny valuation)