Connecting a Fronius inverter

What you’ll need

• A Fronius inverter that’s already paired with a Solar.web account at solarweb.com.
• REST API access enabled on your Solar.web account. Installer-tier accounts have this by default; homeowner-tier accounts may need to request it once from Fronius support (see the troubleshooting section below).
• About three minutes to generate the access keys.

Generating your access keys in Solar.web

1. Sign in at solarweb.com with your usual Solar.web account.
2. Click the user icon in the top-right corner and choose User settings.
3. In the left navigation, pick the API(or REST API) tab. If you don’t see this tab, your account doesn’t have API access enabled yet — jump to the troubleshooting section below.
4. Click Create new key. Give it a recognisable name like solarprod so you can recognise it later if you ever audit your keys.
5. Solar.web will show you two strings: an AccessKeyId (short, public-ish identifier) and an AccessKeyValue(long secret). Copy both somewhere safe — the secret is only displayed once.
6. From the same Solar.web page, also note your PV System ID. It looks like a UUID (00000000-0000-0000-0000-000000000000) and identifies which system you want solarprod to pull from when you have more than one. Single-system users have only one; pick that.

How to connect in solarprod

1. Go to your Account page in solarprod.
2. Find the Cloud inverter card and pick Fronius Solar.web from the provider dropdown.
3. Paste your AccessKeyId, AccessKeyValue, and PV System ID into the three fields. Click Connect.
4. solarprod will run a small probe call against the Solar.web Query API to confirm the keys are valid and the PV System exists, then save the credentials and show your system name.
5. From this point on, every time you run a forecast, solarprod pulls the latest snapshot (battery state of charge, current solar power, current load) from your inverter and uses it to anchor the simulation.

What we read from your inverter

solarprod only ever reads data from your inverter — the Query API is read-only by design, so even if we wanted to we couldn’t change settings, dispatch the battery, or do anything that affects how your system runs. Specifically, we ask Fronius for:

• Current solar power — what your panels are generating right now.
• Battery charge — how full your battery is, as a percentage and converted to kWh against the capacity in your solarprod layout.
• Battery power flow — whether the battery is currently charging or discharging, and at what rate.
• Grid power flow — whether you’re currently importing from the grid or exporting to it, and at what rate.
• Household load — how much power your house is consuming right now.

We don’t pull historical data unless you explicitly ask for the day-chart overlay that compares yesterday’s forecast to what actually happened. We never read personal information, account settings, billing details, or anything else.

Privacy and credentials

Both the AccessKeyId and the AccessKeyValue are held only encrypted — we use Fernet symmetric encryption with a key derived from solarprod’s deployment session secret. The ciphertext sits on your account row in the database; the keys are only ever decrypted in-process, for the duration of a single outbound call to Solar.web, and are never logged, never printed in error traces, and never sent to anyone other than Fronius themselves.

Because Fronius uses long-lived API keys instead of password-based logins, solarprod never sees your Solar.web password. This is genuinely the safer model and is part of why we prefer the Solar.web Query API over the equivalents for some other vendors.

You can disconnect at any time from the same card on the Account page. Disconnecting removes the encrypted keys and the PV-system selection from solarprod immediately. The keys you created in Solar.web aren’t deleted by that — for extra peace of mind, you can also revoke them inside Solar.web’s API tab, which permanently invalidates them on Fronius’s side.

Troubleshooting

• No API tab in User settings — your Solar.web tier doesn’t have REST API access enabled yet. In our experience the fastest route is:
  1. Ask your solar installer. This is Fronius’s own preferred path: installers have privileged access via the Fronius Solar.SOS portal and can toggle REST API access on for systems they commissioned, usually within minutes, without having to go through Fronius support at all. Just tell them: “Please enable REST API access on my Solar.web account so I can use a third-party forecasting tool.” Fronius’s auto-responder to homeowners says exactly this: contact your installer first.
  2. If you can’t reach your installer (out of warranty / company gone / they don’t reply), email Fronius PV-Support directly. The Australian address is [email protected] (other regions: substitute usa, uk, etc., or use the contact page for your country). Expect their first reply to redirect you back to your installer anyway, so try option 1 first if you possibly can.
  3. Phone Fronius AU on +61 3 8340 2900 (Mon–Fri business hours, AEST/AEDT) if you can’t reach the installer and the email auto-replies aren’t routing you to a human.
• “Invalid AccessKey” — the most common cause is pasting only the ID without the Value, or pasting them swapped. Re-open the API tab in Solar.web and copy each string fresh. (You can’t see the secret a second time, so if you didn’t copy it, create a fresh key and use those.)
• “PV System not found” — the PV System ID belongs to a different Solar.web account than the keys, or it was copied from a different system. Double-check the UUID in Solar.web’s dashboard URL when viewing the system you want.
• Snapshot looks stale — the Solar.web Query API caches for up to 5 minutes, so very recent changes at your meter may take a moment to show up.
• I’d rather use the inverter’s local API — some Fronius inverters (GEN24 in particular) expose a local Solar API on your home network at http://<inverter_ip>/solar_api/v1/. solarprod doesn’t use that today because we run in the cloud and can’t reach your LAN. If you’d prefer the local path we’d need to ship a small relay agent on your network — let us know if that’s a deal-breaker and we’ll queue it up.