GoodWe Solar Monitor

A static single-page web app for monitoring a GoodWe solar inverter in real-time. Connects to the SEMS Portal API and Elering Nord Pool API through a CORS proxy, displaying live production data, spot electricity prices, weather, and inverter details.

No backend required — runs entirely in the browser, hosted on GitHub Pages.

Features

• Real-time power output with auto-refresh (5 min day / 30 min night)
• Today, monthly, and lifetime generation stats
• Today's hourly spot price chart (Nord Pool via Elering API)
• Spot price income estimation using sunrise/sunset-aware daylight hours
• Weather conditions from SEMS API (translated to Estonian/English)
• Inverter details (AC phases, DC strings, temperature)
• Dark theme, responsive layout
• Bilingual UI — Estonian (default) and English, switchable via header toggle
• Login with SEMS Portal credentials, optional "remember me"
• Silent token refresh every 25 minutes

Prerequisites

Before you begin, you'll need:

1. A GoodWe inverter registered on SEMS Portal
2. Your SEMS Portal credentials (email + password)
3. Your Power Station ID (UUID) — find it in SEMS Portal → Plant Settings
4. A Cloudflare account (free tier is fine) to deploy the CORS proxy

Set Up Your Own Instance

Step 1: Deploy the CORS Proxy (Cloudflare Worker)

The app cannot call the SEMS and Elering APIs directly from the browser due to CORS restrictions. A small Cloudflare Worker acts as a proxy.

1. Go to Cloudflare Dashboard → Workers & Pages → Create Worker
2. Name it something like sems-proxy
3. Paste the following code and click Deploy:

export default {
  async fetch(request) {
    // Handle CORS preflight
    if (request.method === 'OPTIONS') {
      return new Response(null, {
        headers: {
          'Access-Control-Allow-Origin': '*',
          'Access-Control-Allow-Methods': 'POST, OPTIONS',
          'Access-Control-Allow-Headers': 'Content-Type',
        },
      })
    }

    if (request.method !== 'POST') {
      return new Response('Method not allowed', { status: 405 })
    }

    try {
      const { url, headers, body, method } = await request.json()

      if (!url) {
        return new Response(JSON.stringify({ error: 'Missing url' }), {
          status: 400,
          headers: { 'Content-Type': 'application/json' },
        })
      }

      const fetchOptions = {
        method: method || 'POST',
        headers: headers || {},
      }

      // Only include body for POST requests
      if (fetchOptions.method === 'POST' && body) {
        fetchOptions.body = JSON.stringify(body)
      }

      const response = await fetch(url, fetchOptions)
      const data = await response.text()

      return new Response(data, {
        status: response.status,
        headers: {
          'Content-Type': 'application/json',
          'Access-Control-Allow-Origin': '*',
        },
      })
    } catch (err) {
      return new Response(JSON.stringify({ error: err.message }), {
        status: 500,
        headers: {
          'Content-Type': 'application/json',
          'Access-Control-Allow-Origin': '*',
        },
      })
    }
  },
}

4. Note your worker URL (e.g. https://sems-proxy.<your-subdomain>.workers.dev/) — you'll enter this on the login screen

Tip: Cloudflare Workers free tier allows 100,000 requests/day — more than enough for personal use.

Step 2: Fork and Configure the App

1. Fork this repository
2. Update vite.config.js — change the base path to match your repo name:

   export default defineConfig({
     // ...
     base: '/your-repo-name/',
   })

3. Enable GitHub Pages in your repo settings: Settings → Pages → Source → GitHub Actions

Step 3: Deploy

Push to main and GitHub Actions will automatically build and deploy to GitHub Pages.

The deployment workflow (.github/workflows/deploy.yml) handles everything: install → build → upload to GitHub Pages.

Alternatively, run locally:

npm install
npm run dev

Step 4: Log In

Open your deployed app and enter:

• Email — your SEMS Portal email
• Password — your SEMS Portal password
• Power Station ID — the UUID from SEMS Portal → Plant Settings
• CORS Proxy URL — your Cloudflare Worker URL from Step 1

Tech Stack

• React 19.2
• Vite 7
• Tailwind CSS 4
• Recharts 3
• Lucide React (icons)
• Cloudflare Worker (CORS proxy)

Internationalization (i18n)

The app supports Estonian and English. Estonian is the default language. A language toggle button (EN/ET) is available in the header and on the login screen. The selected language is persisted in localStorage.

Translation files are located in src/i18n/:

• et.js — Estonian translations
• en.js — English translations

Weather conditions from the API are also translated via keyword matching.

Development

npm install
npm run dev          # Dev server at localhost:5173
npm run build        # Production build to dist/
npm run preview      # Preview production build

Or with Docker:

docker compose up --build

How the Proxy Works

The app sends all API requests as POST to your proxy URL with a JSON body:

{
  "url": "https://eu.semsportal.com/api/v2/...",
  "headers": { "Content-Type": "application/json", "Token": "..." },
  "body": { ... }
}

For Elering (GET requests):

{
  "url": "https://dashboard.elering.ee/api/nps/price?start=...&end=...",
  "method": "GET"
}

The proxy forwards the request and returns the response with CORS headers added.

License

MIT