# Volcast - Solar Forecast

> Accurate solar production forecasts for PV systems, up to 7 days ahead. (iPhone/iPad app by Michal Bartosiak.)

- Source: https://appshunter.io/ios/app/volcast-solar-forecast/id6758962799 (this page in markdown: same URL + `.md`)
- Developer: [Michal Bartosiak](https://appshunter.io/developer/1876033141)
- Category: Weather, Utilities
- Price: Free with in-app purchases
- Age rating: 4+
- Requires: iOS 15.1 · 69 MB
- Languages: American English
- Released: 2026-03-24
- Data updated: 2026-09-07
- Monetization: freemium
- User reviews in markdown: https://appshunter.io/ios/app/volcast-solar-forecast/id6758962799/reviews.md

## What is Volcast?

Maximize your solar investment with Volcast – the ultimate PV production forecast tool.
 
Stop guessing when the sun will power your home. Volcast provides an accurate, hour-by-hour solar production forecast for your PV system, covering today and the next 7 days. Designed by solar owners for solar owners, Volcast helps you align your energy-heavy tasks with peak production windows to maximize self-consumption.
 
SMART HOME & HOME ASSISTANT INTEGRATION
Volcast features a professional REST API for Home Assistant users. Export your forecast data directly to your HA dashboards to automate your smart home based on solar availability.
 
ADVANCED PHYSICS-BASED ENGINE
We combine real-time satellite irradiance data with a high-fidelity physics engine. We account for:
 
Multi-String Support: Perfect for complex east-west or multi-roof systems.
 
Bifacial Panels: Specialized modeling for modern modules.
 
AI Auto-Calibration: Our algorithms learn your system's performance over time.
 
Horizon Profiling: Accounts for shading from terrain and obstacles.
 
KEY FEATURES:
 
7-Day Precise Forecast: Hour-by-hour power prediction.
 
Hourly View Toggle: Switch each hour between forecast, actual production, and the difference at a tap.
 
Multi-Device Sync: Production history and calibration stay in sync across every device you sign in on.
 
Notification Center: Evening forecasts, snow warnings, and peak window alerts.
 
Privacy First: Secure processing, no ads, no third-party tracking.
 
PLANS & PRICING:
 
Free: 48-hour high-accuracy forecast.
 
Premium (monthly or yearly): Full 7-day forecast, AI calibration, and Home Assistant API access. Start with a 7-day free trial.

Terms of Use: https://volcast.app/terms
Privacy Policy: https://volcast.app/privacy

Subscriptions automatically renew unless cancelled at least 24 hours before the end of the current period. You can manage subscriptions in your App Store account settings.

## Key features

- 7-day hour-by-hour solar forecast
- Smart home integration (Home Assistant API)
- Advanced physics-based modeling
- AI auto-calibration
- Multi-string and bifacial panel support
- Notification Center alerts

## Pricing and in-app purchases

Base price: Free.

**Subscriptions**

| Subscription | Price | Period |
| --- | --- | --- |
| Volcast Premium · Monthly | $4.99 | per month |
| Volcast Premium · Yearly | $39.99 | per year |

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| Volcast Premium Lifetime | $44.99 | one-time |


## Recent user reviews (2 of 2)

All indexed reviews: https://appshunter.io/ios/app/volcast-solar-forecast/id6758962799/reviews.md

### 5/5 — Great Solar Forecast app

*2026-04-24*

Best solar forecast app I have found.

Allows multiple panel strings that face different directions which none of the others allow.

Better it integrates live with Home Assistant which feeds back “actual” PV production and allows the app to automatically refine and improve its forecasting.

Probably the best part is it’s 100% setup on your phone no website logins required 

Having your solar forecast on your phone is great and allows household planning for running your solar / battery system, lets you plan solar surpluses EV charging 

Nice app 👍

### 5/5 — Brilliant for Forecasting

*2026-04-21*

Honestly, this is exactly the app I’ve been looking for to check my solar forecast. 

It’s clear, easy to use and has a bunch of features. The fact that it learns from your previous production and adjusts the forecast is an absolute game changer!

Bonus points for the Home Assistant integration too!

## Frequently asked questions about Volcast

### What is Volcast's free forecast accuracy?

The free version of Volcast provides a high-accuracy solar production forecast for 48 hours. This allows users to plan their immediate energy needs effectively.

### What are the benefits of Volcast Premium?

Volcast Premium offers a full 7-day forecast, advanced AI calibration for personalized system performance learning, and access to the Home Assistant API for smart home integration. A 7-day free trial is available.

### How does Volcast handle different solar panel setups?

Volcast supports multi-string configurations, ideal for complex east-west or multi-roof systems, and specialized modeling for bifacial panels. This ensures accurate forecasts regardless of your system's complexity.

### Does Volcast have ads?

No, Volcast is privacy-first and does not contain advertisements. It ensures secure processing without ads or third-party tracking.

### How often is Volcast updated?

The app was last updated on June 13, 2026, with version 1.4.2. This indicates a consistent development cycle for improving features and accuracy.

### What devices is Volcast available on?

Volcast is available on iPhone, iPad, and iPod, making it accessible to a wide range of Apple users with solar installations.

### How can I cancel my Volcast Premium subscription?

Subscriptions automatically renew unless cancelled at least 24 hours before the end of the current period. You can manage your subscriptions directly within your App Store account settings.

### What kind of alerts does Volcast offer?

Volcast's Notification Center can provide evening forecasts, snow warnings, and alerts for peak solar production windows, helping you stay informed and optimize energy usage.

## Version history (last 5 releases)

### 1.5.0 — 2026-07-09

• Consistent forecast numbers everywhere — the daily total in the header,
  widgets and calibration screen now always matches the hourly chart, and
  no longer shifts around after you log your production
• More accurate forecasts — better freezing-weather handling, snow cover
  now carries across forecast days, and improved low-sun modeling
  (biggest gains on winter days and early mornings)
• Compass fix — "Measure from nature" now reads your panel direction
  correctly on tilted surfaces and in the Southern Hemisphere
• Ground-mounted systems get a more accurate horizon by default
• Instant fixes — we can now deliver small improvements over the air,
  without waiting for a store update
• Stability and reliability improvements

### 1.4.2 — 2026-06-13

Smarter calibration
Forecast adjustments now build up gradually from real measurements — fixing a mid-day under-prediction that affected some users.

Fresh forecast every morning (Premium)
Overnight server-side refresh means your forecast is already updated before you open the app.

No more stuck loading screen
The app now recovers gracefully if the initial forecast load fails, instead of getting trapped on the splash screen.

Fixed: navigation to Settings and Calibration
Tapping Settings or Calibration from the forecast screen now always navigates correctly — previously it could leave you stuck with no way to switch tabs.

Edit horizon obstacles by tapping them
No need to delete and re-enter. Also fixed: 360° obstacles (0°–360°) now apply correctly.

Bug fixes: calibrated values in the past-hours chart, "already owned" purchase error now offers Restore.

### 1.4.1 — 2026-05-26

• Bug fix: 7-day and 16-day forecast charts could show different values for overlapping days after a config change. Now in sync.
• New (Premium): Preview Mode in the obstacle editor. Forces a recompute so you can quickly iterate and find the obstacle sweet spot.

### 1.4.0 — 2026-05-21

• New monthly and yearly plans with a 7-day free trial. Lifetime stays available for a limited time.
• Manage your subscription from Settings → Subscription.
• New hourly view toggle: forecast, actual, or difference (Δ).
• Production history now syncs across all your devices.
• Major forecast accuracy fix for installations with terrain shadowing.
• Notification language fix for some users.
• Plus dozens of UI and copy improvements.

### 1.3.0 — 2026-04-16

• Italian language support — now in 13 languages 
• Real-time nowcast correction for Home Assistant users 
• Dashed forecast line on production chart for easy comparison 
• Hourly forecast now shows kWh instead of kW
Fixes:
• Fixed curtailment text cut off on iOS
• Push notifications sent in user's chosen language
• Locale-aware date formatting in extended forecast
• Translation and precision improvements

## Related topics

[solcast](https://appshunter.io/ios/topics/solcast) · [solar energy forecast](https://appshunter.io/ios/topics/solar-energy-forecast) · [softwrench](https://appshunter.io/ios/topics/softwrench)

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-09-07.*