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We need two kinds of data to participate in a market:
  • operational metering: readings from the asset to understand and optimize asset usage. We typically need these with as low latency as possible
  • settlement metering: readings from the asset or site boundary meter, which we send to the market operator as proof of delivery
Operational metering always comes from the asset we’re optimising. Settlement metering can also come from the asset (known as asset-metering), but in many markets we’re required to obtain readings from the site boundary meter (boundary-metering). Axle can obtain boundary meter data for consenting households if you don’t already have access to it. In cases where we use asset metering, we may have to pass additional qualification checks to confirm that the metering provided by the asset is sufficiently accurate.
MarketAsset Metering Allowed?
DNO FlexYes
Capacity MarketYes (1.5% accuracy)
DFSYes
WholesaleYes (CoP11 required)
CoP11 is a UK standard which is required to use an asset’s metering in the wholesale market. Axle has extensive experience qualifying assets for CoP11 - please get in touch to discuss how we can qualify your asset

Communicating asset telemetry

The kind of telemetry we gather varies by asset.
  • Charge Power (kW)
  • Plugged in (boolean)
  • State of charge (SOC) (%)
  • Plugged in (boolean)
  • Charge Power (kW)
  • State of charge (SOC) (%)
  • Inverter Power (kW)
  • Grid Power (kW)
  • Solar Power (kW)
  • Power (kW)
  • Temperature (°C)
For sites with a CT clamp installed at the grid boundary, Axle can collect half-hourly CT clamp readings through supported asset integrations.CT clamp data measures site-level grid I/O similarly to a boundary meter, and is treated as such when verifying delivery.

Reading direction and sign convention

When you send readings to the Asset Readings endpoint, the sign of each value tells us its direction. For readings that can flow either way, the convention is positive = import, negative = export:
  • Import means power/energy flowing in — from the grid into the site, or into the battery (charging).
  • Export means power/energy flowing out — out to the grid, or out of the battery (discharging).
All other reading types are unidirectional and must be non-negative. The table below summarises the label values accepted by the endpoint:
Reading (label)UnitSign convention
boundary_import_kwkWPositive = import from the grid, negative = export to the grid
battery_inverter_import_kwkWPositive = into the battery (charging), negative = out of the battery (discharging)
solar_power_kwkWGeneration only — always >= 0
charger_consumption_energy_kwhkWhConsumption only — always >= 0
charger_lifetime_consumption_energy_kwhkWhCumulative lifetime consumption — always >= 0
boundary_lifetime_import_energy_kwhkWhCumulative lifetime import across the site boundary — always >= 0
boundary_lifetime_export_energy_kwhkWhCumulative lifetime export across the site boundary — always >= 0
provisional_consumption_kwhkWhConsumption only — always >= 0
battery_state_of_charge_pct%Between 0 and 100 (inclusive)
battery_stored_energy_kwhkWhAlways >= 0
You can push telemetry to our Asset Readings endpoint, where you’ll find a list of accepted reading types

Obtaining boundary meter data

Axle can obtain boundary meter data on your behalf, with user’s consent and proof of address. Contact us to discuss the best way to incorporate this consent collection into your product.