HelioPeak Blog

Technical articles about solar monitoring, PVOutput, home batteries, and the data behind residential solar, written by Sven, developer of HelioPeak.

15 articles · written from Belgium for everyone running residential PV

Article 01 Installation

What to consider before installing solar panels

The pre-installation decisions that quietly shape your solar system's 25-year performance. Orientation, inverter sizing, panel …

9 min read
Article 02 Economics

Self-consumption versus feeding back to the grid

Net metering is phasing out, capacity tariffs are in, dynamic contracts are real. How to think about self-consumption versus gr…

9 min read
Article 03 Monitoring

Why a smartphone app changes how you understand solar production

Data without context decays in days. How a well-designed solar monitoring app turns raw production numbers into pattern recogni…

9 min read
Article 04 PVOutput

What is PVOutput.org, and why solar owners keep coming back

PVOutput has been quietly hosting residential solar data for over 15 years. Why this Australian platform became the European ho…

5 min read
Article 05 PVOutput

Getting your data into PVOutput

Direct push, auto uploader, Home Assistant bridge, custom scripts, manual entry. The five ways to get your inverter data into P…

9 min read
Article 06 Monitoring

Setting up consumption monitoring

How to add consumption monitoring to your solar setup in Belgium. P1 port readers, Shelly Pro 3EM, and inverter CT clamps compa…

9 min read
Article 07 HelioPeak

How HelioPeak fits into the picture

What HelioPeak is, what it isn't, and the design decisions behind a privacy-first native iOS app for solar monitoring. Honest a…

18 min read
Article 08 Equipment

Home batteries in 2026

A real-world comparison of Sonnen Battery 10 and three Marstek Venus E v3 units. Wall-mounted versus plug-in, German engineerin…

18 min read
Article 09 Data

Reading your solar charts: what the numbers actually mean

The metrics that turn solar data into useful diagnostics. Specific yield, performance ratio, peak power, and how to read daily …

15 min read
Article 10 Data

Estimates versus reality

Three kinds of estimates, real-world losses, the first-year disappointment myth, and how to build your own performance baseline…

13 min read
Article 11 Diagnostics

How to spot a failing solar panel before your installer does

From data signatures to visual inspection, from optimiser failures to encapsulant browning. Spotting solar panel problems early…

20 min read
Article 12 Reflections

A year of data: what the seasons taught me

What several years of solar data taught me about the Belgian seasons. The dark months, the April-May surprise, the summer plate…

14 min read
Article 13 Apps

Solar monitoring on iOS: comparing the options in 2026

An honest comparison of the four PVOutput iOS apps in 2026: PV Output by McDonald, PVOutput Plus, MyPVOutput, and HelioPeak. Wi…

14 min read
Article 14 Privacy

The privacy question: what data does a solar monitoring app actually need?

What a solar app really needs to function, what it commonly collects beyond that, and the practical questions to ask of any app…

15 min read
Article 15 Behind the scenes

Building HelioPeak: lessons from indie iOS development

The story behind HelioPeak: starting without Swift experience, building with AI assistance, getting the first hundred users, an…

15 min read