Configure site energy contracts#
This page is for installers and account managers configuring the commercial contract terms of a site through Configuration > Site > Energy Contracts in the Octave Portal.
Important
If one of the assets on site is controlled by the Octave EMS (e.g. BESS Local Optimizer, Grid Services, PV day-ahead curtailment), these settings directly drive how energy is priced and how the EMS optimizes the energy flows to maximize incremental profits. Make sure the configured contracts match the signed commercial agreements with the energy supplier and DSO. For questions, contact your account manager.
Site energy contracts configuration in the portal
The following video provides a step-by-step guide on how to configure site energy contracts.
The site energy contracts hierarchy#
A site energy contract bundles several commercial inputs that the EMS combines to price every kWh consumed or injected. They follow the same hierarchy as the configuration screen, top to bottom:
- Valid from: effective date of the contract version.
- Grid connection (DSO): connection level and capacity-tariff exposure.
- Offtake Contract: commercial terms for energy consumed from the grid.
- Taxes & Certificates: regulated charges added on top of the offtake price.
- Injection Contract: commercial terms for energy injected into the grid.
- PV contract (optional): separate settlement for on-site PV generation.
Each version is bound to a Valid from date, so historical contracts remain available for back-testing and reporting.
Prerequisites#
Before you configure energy contracts, make sure that:
- The site has a valid postal code in Site Settings. The region (Flanders, Wallonia, Brussels) is derived from it and drives validation.
- You know the site's grid connection level (e.g. 1-26 kV-net in Flanders, BT/MT in Wallonia/Brussels) and whether the connection is peak-measuring.
- You have the signed energy contract from the supplier (offtake / injection prices, multipliers, markups, floor prices).
- You have the latest certificate prices (GSC & WKC) from the energy supplier.
- You have an estimation of the federal excise tax based on the expected yearly offtake volume (see Taxes & Certificates).
Configure the contracts#
Open Configuration > Site > Energy Contracts.
1. Pick or create a contract version#
Use the controls at the top of the screen:
- Selected energy contract: dropdown listing every contract version saved for the site, labelled by their Valid from date.
- ADD NEW CONTRACT: create a new contract version, typically for a future Valid from date (e.g. a renewal or re-negotiation).
- REMOVE THIS CONTRACT: delete the currently selected contract version.
- Valid from: date and time from which the selected contract terms become effective.
Tip
The Selected energy contract, ADD NEW CONTRACT and REMOVE THIS CONTRACT controls become visible once a first contract has been configured.
2. Set the grid connection (DSO)#
In the DSO block, capture how the site is physically connected to the distribution grid:
- Pick the Grid connection level. Allowed values depend on the region:
- Flanders: 1-26 kV-post, 1-26 kV-net, 26-36 kV-post, 26-36 kV-net, ≤1 kV and Laagspanningsnet.
- Wallonia: BT, T-BT, MT, T-MT.
- Brussels: BT and MT.
- Toggle Exposed to Capacity Tariffs? based on the connection agreement. Enabled by default.
Warning
In Flanders, all medium and high voltage connections (1-26 kV, 26-36 kV, ≤1 kV) must keep Exposed to Capacity Tariffs enabled. In Brussels, MT connections must also stay peak-measuring. Disabling these combinations raises a validation error on SUBMIT CHANGES.
3. Configure the offtake contract#
The Offtake Contract captures commercial terms for energy consumed from the grid. Pick the structure that matches the signed agreement:
- Fixed price: flat €/MWh independent of market conditions.
- Quarter-Hourly or Hourly Day-Ahead: indexed on the wholesale day-ahead market, typically called dynamic contracts, with prices that fluctuate every quarter-hour or hour (Day-Ahead Price × multiplier + markup).
- Time of Use: different pricing for peak and off-peak periods. Each period can itself be Fixed price or Day-Ahead.
- Imbalance: indexed on the imbalance market (Imbalance Price × multiplier + markup).
Unsupported contracts
The following contracts are not yet supported:
- Monthly/Quarterly Day-Ahead: contracts based on an arithmetic monthly or quarterly average of the Day-Ahead prices.
- Click/Volume based.
Resulting Formula
The EMS displays the Resulting Formula at the top of the section (e.g. Day-Ahead Price × 1 + 1.74). Use it as a quick sanity check that the inputs match the signed contract.
Finally, fill in the Taxes & Certificates at the bottom of the section: the Contribution for green and power certificates (GSC & WKC) and the Federal Excise Price.
For the federal excise tax on electricity (bijzondere of federale accijns / accise fédérale), the true tariff is calculated on an annual basis according to a degressive rate per consumption bracket (see Article 39 of the applicable legislation). For simplicity, a fixed tariff per MWh is assumed, typically 12 €/MWh. Other fixed costs related to the federal excise tax (e.g. Vlaamse energieheffing) should be ignored.
4. Configure the injection contract#
The Injection Contract captures commercial terms for energy exported to the grid. The same four contract structures are available as for offtake. Two extra parameters are exclusive to injection day-ahead contracts:
- Floor Price: optional minimum guaranteed price. The resulting price is clamped to this value.
- Exposed To Belgian Solar Imbalance Index?: when selected, the BSI Index is subtracted from the price.
5. Configure the optional PV contract#
The PV contract section is optional. Use it only when on-site solar generation is settled under a separate commercial agreement (typically called a Power Purchase Agreement). This section should also be used to add the green certificate price per MWh in case the PV installation still qualifies for green certificates.
Currently only the Fixed price structure is supported:
- Price (€/MWh): the agreed flat price for PV generation.
Leave the section collapsed and unconfigured if PV is settled under the regular grid injection contract.
6. Submit your changes#
When all required fields are filled in:
- Click SUBMIT CHANGES to validate and save the new contract version.
- Click RESET to discard your edits and restore the currently saved values.
If any validation rule fails, the offending fields are highlighted with the corresponding error message. Fix the inputs and submit again.
Field reference#
Grid connection (DSO)#
| Field | Unit | Required | Description |
|---|---|---|---|
| Grid connection level | n/a | Yes | Voltage level at which the site is connected. Allowed values depend on the derived region. |
| Exposed to Capacity Tariffs? | true / false | Yes | Whether the site pays capacity tariffs based on measured peak power. Default: true. |
Day-ahead parameters#
| Field | Unit | Default | Description |
|---|---|---|---|
| Granularity of Day-Ahead Price | n/a | Quarter Hourly | How the day-ahead price is calculated. Choose Quarter Hourly or Hourly. |
| Multiplier | n/a | 1 | Multiplier applied to the day-ahead price. |
| Markup | €/MWh | 0 | Fixed amount added on top of the day-ahead price. |
| Floor Price | €/MWh | n/a | Injection only. Optional minimum guaranteed price. |
| Exposed To Belgian Solar Imbalance Index? | true / false | false | Injection only. Exposure to the BSI Index. |
Time of Use parameters#
| Field | Unit | Default | Description |
|---|---|---|---|
| Peak Contract | n/a | n/a | Nested Fixed price or Day-Ahead contract applied during peak hours. |
| Off-Peak Contract | n/a | n/a | Nested Fixed price or Day-Ahead contract applied during off-peak hours. |
| Peak Start Hour / Peak End Hour | h | 7 / 22 | Peak window each day. The end hour is exclusive. |
| Weekend as Off-Peak | true / false | true | When enabled, Saturday and Sunday are always off-peak regardless of the time. |
| Bank Holidays as Off-Peak | true / false | true | When enabled, Belgian bank holidays are always off-peak regardless of the time. |
Imbalance parameters#
| Field | Unit | Default | Description |
|---|---|---|---|
| Multiplier | n/a | 1 | Multiplier applied to the imbalance market price. |
| Markup | €/MWh | 0 | Fixed amount added on top of the imbalance price. |
Flex parameters (only for BESS)#
| Field | Range | Default | Description |
|---|---|---|---|
| Day-Ahead Contract | n/a | n/a | Underlying day-ahead contract used by the flex formula. |
| Day-Ahead Factor | -1 to 1 | 0 | Exposure to the day-ahead price. Negative values capture the spread between imbalance and day-ahead. |
| Imbalance Factor | 0 to 1 | 1 | Exposure to the imbalance price. |
| BESS Allowed to Inject | true / false | true | Whether the battery is permitted to export energy to the grid. |
Taxes & Certificates#
| Field | Unit | Required | Description |
|---|---|---|---|
| Contribution for green and power certificates (GSC & WKC) | €/MWh | Yes if the offtake contract is configured | In Flanders, both GSC and WKC apply. In Brussels and Wallonia, only GSC applies. |
| Federal Excise Price | €/MWh | Yes if the offtake contract is configured | Federal excise tax on electricity, captured here as a fixed €/MWh equivalent. |
Troubleshooting#
These are common error messages you may encounter when configuring energy contracts.
Cannot validate the energy contracts if the region is unknown
The site has no valid postal code. Open Site Settings, set a correct Belgian postal code, then retry.
Invalid grid connection level for the given region
The selected Grid connection level does not belong to the region derived from the postal code. Pick a level allowed for that region (e.g. BT/T-BT/MT/T-MT in Wallonia).
Medium or high voltage connections in Flanders must be peak measuring
Enable Exposed to Capacity Tariffs? for any 1-26 kV, 26-36 kV, or ≤1 kV connection in Flanders. The same applies to MT connections in Brussels.
The Resulting Formula does not match my contract
Double-check Multiplier and Markup. A common mistake is encoding a percentage tax as a markup instead of converting it to a multiplier (e.g. a 5% tax on offtake is multiplier = 1.05, not markup = 5).
Floor price or BSI index do not appear on my offtake contract
Both Floor Price and the Belgian Solar Imbalance (BSI) Index factor are injection-only parameters and are intentionally hidden on offtake contracts.