Case study

Taming the sun with PV flexibility in Switzerland

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As solar adoption accelerated across Switzerland, Romande Energie saw an opportunity rather than a problem. Together, we built a flexibility platform that aggregates and steers distributed PV in real time, turning decentralised assets into a reliable portfolio resource. What began as a focused pilot has evolved into a scalable solution, now rolling out to end consumers and laying the foundation for a more balanced, resilient energy system.

Facts and figures

Powernaut & Romande Énergie

Facts and Figures

Type: Energy retailer

Location: Switzerland

Sites: Full injection and self-consumption sites

Assets Managed: Solar installations

Business Target: MVP by January 2026

Forecast Accuracy: ~12 kWh average error per quarter-hour for 1.35 MWp pool

Key Result: Validated technical and business case for distributed PV portfolio self-balancing

Context

Switzerland’s energy scene is very active, with utilities racing to integrate growing renewables like solar without upsetting the grid or their portfolios. All this is happening at the time when legislation is catching up, and market liberalisation and energy communities are a hot topic.

Problem

As more customers installed solar panels, Romande noticed rising balancing costs. They saw this growth not as a problem, but as an opportunity to apply the extra flexibility from these small, spread out solar installations for balancing their portfolio.

Approach

The collaboration was agile, beginning with a proof of concept on three PV sites following an RFP win, tested alongside longtime incumbents in the flexibility space. This scaled to a minimum viable product with deep integration into Romande’s trading and billing systems.

ShortBalancedLong
+3.8 MWopen position, closed by steering the solar pool
Imbalance is settled against the portfolio every quarter hour

The challenge

As more customers installed solar panels, Romande saw imbalance costs rise. Managing a growing number of small, distributed PV assets made real-time control increasingly complex.

The key challenge was clear: how to precisely monitor, pool, and steer distributed solar installations without compromising customer self-consumption or operational reliability.

“The problem we had was connecting and steering many decentralised assets, especially solar.”
Patrick Biro, Venture Architect at Romande Energie
  1. ForecastPV and load, day ahead
  2. Nominatethe portfolio position
  3. Steerdistributed solar in real time
  4. Closethe gap before settlement
Nominate the position, then close it with flexibility

The solution

Powernaut’s workspace allowed Romande to aggregate distributed PV installations and operate them as a single, controllable portfolio. At the heart of the solution: real-time portfolio self-balancing, smart disaggregation down to site level, accurate day-ahead and intraday forecasting, and direct integration with trading and billing systems.

“Powernaut allowed us to steer all these assets as if they were one power plant.”
Patrick Biro, Venture Architect at Romande Energie

Implementation

The collaboration followed a pragmatic, step-by-step approach focused on proving value early.

  1. Proof of concept. After winning a competitive RFP, Powernaut and Romande launched a PoC across three PV sites, covering both full-injection and self-consumption setups.
  2. Real-world testing. Manual activations, forecast accuracy, and steering stability were tested under live conditions, alongside incumbent flexibility providers.
  3. From PoC to MVP. The success of the pilot paved the way for a full MVP, deeply integrated into Romande’s trading and billing operations.
Before100%
After30%
Imbalance cost before and after, 70% lower

The impact

The results validated both the technical and commercial case for distributed PV flexibility.

High-precision portfolio control

Average deviations of just around 12 kWh per quarter-hour across a 1.35 MWp solar pool.

Lower imbalance risk and costs

By actively steering distributed PV in near real time, Romande significantly reduced exposure to imbalance penalties and improved portfolio self-balancing.

A platform built to grow

What started with solar is ready to expand to batteries, EVs, and heat pumps, providing a future-proof flexibility backbone as asset diversity increases.

Value reaching end consumers

Better portfolio control and integrated flexibility enable more competitive pricing and ensure customers benefit directly from the energy transition.

“If energy and flexibility aren’t integrated, it’s the consumer who gets less value and higher costs.”
Patrick Biro, Venture Architect at Romande Energie

Collaboration

From day one, the collaboration was hands-on and iterative. By testing ideas early, aligning closely with trading and operations teams, and focusing on real-world constraints, Powernaut and Romande Energie were able to move quickly from pilot to production.

The future

With a scalable flexibility platform in place, Romande is positioned to grow both the volume and variety of assets under management.

What started with solar is becoming the foundation for a broader distributed flexibility strategy, one that supports the grid, the portfolio, and the people connected to it.