April 15, 2026

Episode 23: Rami El Geneidy (EnergyHub) - What It Really Takes to Build and Exit in Energy Flexibility

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Episode summary

Rami El Geneidy, Technical Director at EnergyHub and exited co-founder of Kapacity.io, discusses energy flexibility, heat pump control, and the startup journey on Episode 23 of Scaling Green Tech, a podcast by Adopter.

El Geneidy traces how Kapacity.io grew from PhD research at the London-Loughborough Centre for Energy Demand Studies, through Conception X and Y Combinator, to acquisition by EnergyHub. Kapacity.io built technology to reduce energy costs and emissions from heat pumps in commercial and residential buildings. The company validated demand by selling building readiness surveys before the product existed, then built first for commercial real estate before pivoting to residential heat pumps when per-building integration barriers limited growth. To crack the conservative energy company market, Kapacity.io first released a consumer product that demonstrated real cost savings to homeowners - then used that proof to sell through energy companies. After five years, the founders accepted an acquisition by EnergyHub, where the two companies' visions for energy flexibility at scale aligned.

This episode is relevant for energy technology founders building hardware-adjacent software, PhD researchers considering the startup route through programmes like Conception X or Y Combinator, and climate tech operators navigating pivots, fundraising timing, and acquisition decisions.

Guest profile

Rami El Geneidy is a Technical Director at EnergyHub and the exited co-founder of Kapacity.io. He studied at Aalto University in Helsinki, where he met his future co-founders. After university, he worked in wind power before completing a PhD at the London-Loughborough Centre for Energy Demand Studies. His research focused on smart control algorithms and building energy flexibility. He is also a certified air-to-air heat pump installer in Finland.

Kapacity.io was a Y Combinator-backed startup (2021 remote batch) that controlled heat pumps in residential and commercial buildings to reduce energy costs and emissions through energy flexibility. The company was acquired by EnergyHub after approximately five years of operation. Prior to the acquisition, Kapacity.io pivoted from commercial real estate to residential heat pump control, selling through energy companies rather than direct to consumers.

Find Rami on LinkedIn.

Key takeaways

  • Kapacity.io validated demand before building its product by selling building readiness surveys - assessments of whether smart controls could be implemented in a given building. This generated revenue and tested willingness to pay from day one.
  • Commercial real estate buildings behave like "snowflakes," according to El Geneidy. Each has unique automation systems, interfaces, and engineering requirements, making software-only control products difficult to scale without significant per-building integration work.
  • Residential heat pump systems are more uniform than commercial building systems, which made them a more scalable market for Kapacity.io. Commercial buildings offer more kilowatts per installation and were the company's original focus, but the residential pivot enabled faster growth.
  • Energy companies are conservative, low-margin businesses where risk-taking is not typical. Kapacity.io built credibility by first releasing a consumer product that demonstrated real electricity cost savings to homeowners, then used that proof to sell to energy companies.
  • Heat pump adoption in Europe is held back by high upfront capital costs and stranded investment in existing gas and oil infrastructure. The installation and servicing industry is also underdeveloped in markets like the UK and Germany - unlike the Nordics, where no legacy gas network existed.
  • Building stock renews at approximately 1-2% per year. Regulation targeting new builds alone would theoretically take around a hundred years to affect the full existing stock. Smarter funding schemes such as heat pump leasing are critical to accelerating uptake.
  • Hardware access remains a significant barrier for software startups in the heat pump space. Manufacturers' systems sit behind contracts rather than open APIs, unlike the relatively open access model of LLM providers such as OpenAI.

topics covered

  • Explaining Kapacity.io and energy flexibility in buildings
  • From Aalto University and wind power to a PhD in energy demand
  • Conception X and formally founding the company
  • Selling building surveys as early validation
  • Y Combinator and the two things a startup needs to do
  • Charging from day one and why free pilots are dangerous
  • Pivoting from commercial real estate to residential heat pumps
  • Building credibility through a consumer product before selling to energy companies
  • The acquisition by EnergyHub and founder decision-making under uncertainty
  • Barriers to heat pump adoption across Europe and the UK
  • Opportunities for AI and LLMs in the heat pump and installer space
  • Hardware access as a bottleneck for software startups
  • Advice for PhD researchers considering the startup path

Frequently asked questions

What is energy flexibility in buildings?
Why are heat pumps less popular than electric vehicles?
What is Conception X?
How can AI help scale heat pump adoption?
Why do software startups struggle with hardware integration in the heat pump market?

About Scaling Green-Tech

Scaling Green-Tech by Adopter is a podcast for people shaping the future of climate technology - founders, investors, and ecosystem leaders at the forefront of adaptation and resilience solutions. As part of Adopter’s mission to accelerate the adoption of high-impact climate innovation, the podcast aims to amplify real voices and practical insights that can help others navigate the startup journey. These conversations go beyond the hype to bring real, unfiltered stories - the wins, the roadblocks and everything you need to know in between.

Read the full transcript here
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