Generation system
This guide shows how to utilise FlatPeak to calculate and report cost savings and export revenue for systems that generate energy, such as solar photovoltaic (PV) installations or wind turbines.
Design
Once the customer completes the Connect flow, or if you imported their tariff:
To calculate the cost-benefit of your system’s operation:
- Supply your customer’s premises when your system generates (supplied energy).
- Export surplus energy to the grid.
To determine the savings and earnings achieved by your system:
- Log supplied energy to meter-records API under the IMPORT tariff.
- Log exported energy to the meter-records API under the EXPORT tariff
- When you want to display savings and earnings, call the cost-calculation API to get the value of energy your system has supplied and exported.
Implementation
Log supplied energy
Log supplied energy
When your system supplies the energy it generates to your customer’s premises, log it as if it were supplied from the grid. This is so it can be priced at the value of the grid import tariff at the time, enabling you to demonstrate the savings your system creates.
Where monitored, exported energy to the grid (i.e. not consumed by the property first) should first be substracted from the generation readings. This enables the accurate calculation of both value streams, the value of avoided grid energy and the value of payments received for energy exported to the grid.
Submit meter records from your system to meter-records API at device-level, setting direction=EXPORT and tariff_rate=IMPORT:
Log exported energy (where monitored)
Log exported energy (where monitored)
When your system exports energy to the grid, log it using the export tariff. To make this measurement, you will place a CT clamp or Meter on the property power feed in the configuration that measures exported energy (export CT clamp / Meter).
- Log export energy to meter-records API, at location-level (i.e. with no
device_id), settingdirection=EXPORTandtariff_rate=EXPORT.
Display savings and earnings
Display savings and earnings
Step 1 - Get monetary value of supplied energy:
Call the cost-calculation API and make request on device-level setting direction=EXPORT, tariff_rate=IMPORT and aggregation=DAY. The response will include the monetary value of energy that your system supplied to your customer’s premises.
Step 2 - Get monetary value of exported energy:
Next, call the cost-calculation API and make a request on the location-level, covering the same time period and using the same aggregation value. The response will include the monetary value of energy your system exported to the grid.
Step 3 - Calculate savings and earnings:
The sum of the tariff.value figures in the two above requests will represent savings plus earnings achieved by your system.
The example below covers a day period and works out as follows:
- Supplied 24.5KWh of energy at total value of €6.86;
- Exported 16.9KWh of energy at total value of €2.03;
- Calculate savings as
€6.86grid costs avoid, plus export revenue of€2.03making a saving of €8.89 savings.