Energy management for solar and battery storage

What is a home energy management system?

A home energy management system, or HEMS, connects generation, storage, consumption and the grid connection. It does more than collect readings: it turns them into a current installation state. Only when power, direction, timestamps and device quality agree can energy management reliably determine whether solar power is being used directly, stored in a battery or imported from the grid.

GridFusion implements this task locally and without tying its core to one vendor. The Energy Engine knows no Solakon, Shelly or other vendor class. It receives only normalised data and capabilities. Protocols, authentication, scaling and sign conversion remain inside their respective drivers. This protects the core from vendor-specific assumptions and allows multiple meters, batteries, inverters or solar arrays.

How measurements become a safe energy decision

1. Measure energy locally

A suitable meter measures energy flow at the grid connection. Inverters, battery storage and other devices provide the values their documented interfaces actually expose. GridFusion assigns every device a generic role and explicitly reports connectivity, data age, quality and available capabilities.

2. Normalise and validate values

Power is processed internally in watts and time as UTC epoch milliseconds. Comparisons remain independent of presentation, time zone and vendor format. Freshness, plausibility and completeness are checked before any control decision. If grid metering is stale or invalid, no new battery command is created. A safe state takes priority over a supposedly optimal action.

3. Evaluate the complete energy state

The Energy Engine considers more than one reading. It combines available solar surplus, household consumption, grid import or export, battery state, configured limits and current data quality. Prices and forecasts may add context, but they can never replace local measurement.

4. Derive a bounded decision

A decision must remain within documented power, state-of-charge and timing limits. Direction changes, ramps and device capabilities are taken into account. A driver may only advertise functions documented for the exact model. Where an authoritative source is missing, the uncertain feature remains disabled and marked for verification.

5. Protect control once more

Solakon writes have an additional single central Safety Gate. Unless solakon_write_enabled is explicitly active, every write attempt ends with “Write disabled”. A web interface, cloud feature or remote request cannot bypass that gate. Read-back, timeouts and an independent device fail-safe remain necessary even after controlled approval.

Combining solar self-consumption and battery storage

Self-consumption optimisation means using as much locally generated energy on site as practical without exceeding technical limits. Simply charging the battery whenever a brief surplus appears is not enough. The system has to determine whether the reading is stable, whether battery capacity remains available and whether stronger solar production is expected later in the day.

A battery is not a lossless energy source. Charging and discharging losses, permitted state of charge and available power affect its value. GridFusion models these as generic battery properties. Vendor-specific translation happens exclusively in the driver, keeping optimisation understandable when another storage product is added later.

Dynamic electricity prices: every interval matters

Dynamic tariffs may change every quarter hour or use other interval lengths. Looking only once per hour can therefore be inaccurate. GridFusion is designed for variable intervals and negative prices, and keeps wholesale and retail prices separate. A price provider supplies normalised time windows; local control decides whether they are usable and fresh enough for the specific installation.

A low price is not itself a charging command. Battery capacity, efficiency, expected solar production, consumption and valid local measurements belong in the same assessment. Provider traffic runs outside the local control path. If a service cannot be reached, measurement and safe local operation continue.

GridFusion only uses price sources whose technical and legal use has been reviewed for the product. Providers that require a personal supply contract or cannot be used cleanly for this purpose are not presented as general product data sources.

Weather and solar forecasts as optional planning inputs

A solar forecast can help reserve battery capacity for expected generation or make expensive grid imports less likely. GridFusion models one or more physical solar arrays using confirmed orientation and capacity. Provider data is validated, cached and reduced to a generic forecast state before the Energy Engine or user interface consumes it.

A forecast is never a measurement. It has an age, quality and uncertainty. If it is missing, implausible or fully expired, it must not cause aggressive control. Actual generation and the forecast can be compared over time to assess quality for each installation. Device-specific model building runs only on the central server and only after local consent; Control 7 neither trains nor executes an AI model.

What happens during an internet, device or storage outage?

Robust energy management has to cover more than normal operation. If internet access fails, new prices, weather data, backups or updates may be unavailable. Local measurement and control remain separate. If the relevant meter or a controlled device stops delivering fresh values, however, the system changes to a safe and visible state and creates no new setpoint.

A missing SD card must not block the energy path either. Historical records pass through bounded queues to the Storage Manager. Under pressure, the newest relevant samples are retained and losses are exposed through metrics. GridFusion does not automatically format storage media and never sacrifices configuration to make room for history.

Explore the relevant GridFusion topic

The feature overview separates current system components, pilot validation and planned extensions. Compatibility explains how devices are verified and added as drivers. Practical guidance for setup, prices, forecasts, privacy and troubleshooting is available in the knowledge base.