Energy Hub: solar and EV charger monitoring

The brief

Energy Hub is an MFB Solutions product, not client work. It started with a very specific problem on our own installation.

Anyone with a solar plant and an EV charger usually ends up with several separate tools: the manufacturer’s inverter portal, the charger’s app and a spreadsheet for everything those tools do not show. None of them answered the question we cared about: are we charging the car with our own surplus or paying for grid power, and what does it cost us?

We wanted one place that sees both the plant and the charger, and that can line up charging with generation on its own.

The approach

We read data directly from the equipment. The inverter is read over Modbus, and the charger connects to the system over OCPP 1.6J, the standard chargers use to talk to management systems. Data goes into our own database rather than through somebody else’s cloud, so we can keep and process it however we need.

The charging logic runs on top of that data. The system tracks how much the plant is producing above household consumption and adjusts charging power to match. When there is not enough sun, charging pauses or drops to an agreed minimum, depending on the selected mode.

The app can be set up for a plant and a charger together, or for just one of the two. One account can hold several locations, and only a user with the manager role can change prices and alarm settings.

What we delivered

• A live dashboard: generation, consumption, energy flow through the day and charger status
• Charging modes such as solar only and a combination of minimum power plus solar
• Starting and stopping a charge from the app, without walking to the charger
• A seven-day generation forecast and an hourly forecast for the next 48 hours, based on the plant’s location
• Tariff settings (single or dual rate) and the feed-in price for surplus, used to calculate savings
• An estimate of avoided CO₂ and daily self-sufficiency
• Weekly and monthly views, month-to-month comparison, plus export and a monthly report
• Notifications and alarms, for example when the inverter stops reporting or the charger reports a fault
• A log of OCPP messages for diagnosing the charger
• Sign-in with email, Google or Apple

Technology

The interface is a web application that installs on a phone like any other app, through the add to home screen option, and then opens full screen. On Android the app is also published on Google Play, and on iPhone it installs from the home screen, without the App Store. Generation and consumption time series are stored in a database built for that kind of data, and the charger can also connect over an encrypted connection.

The outcome

Several separate tools have been replaced by one, and car charging lines itself up with what the plant is producing. Energy Hub is also our testing ground for industrial protocols such as Modbus and OCPP, knowledge we use on client integrations too.

This is a private installation, so access is behind a login. The link leads to a sign-in screen, not to the dashboard.