Based on [node-red-contrib-solar-power-forecast-plus] (https://flows.nodered.org/node/node-red-contrib-solar-power-forecast-plus) (https://github.com/jdefunes/node-red-contrib-solar-power-forecast-plus)

Thanks to Jacobo De Funes.

node-red-contrib-solar-forecast-plus

A Node-RED node to forecast the power output (in watts) of a solar array of panels under ideal conditions at a specified time.

Input message payload requires a timestamp for calculation of solar power output at time specified. Timestamp can be current time or any time from the past or future. Can also receive on object the parameters for dynamic requests (see Input below) which, if in request, will override parameters entered on the Configuration page.

Uses the suncalc to calculate the current sun position. Power forecast is adjusted for panel tilt, orientation, altitude, panel area, number of panels and panel efficiency.

Configuration

• Name
• Latitude & Longitude - physical location of the solar array.
• Panel Tilt - degrees (0..89.999) relative to horizontal (0).
• Panel Orientation - compass bearing in degrees from North (0..359.999).
• Altitude - panel(s) location in metres above sea level.
• Panel Area - surface size of a single panel in m^2.
• Number of Panels - number of panels in the array.
• Panel Efficiency - the conversion efficiency (usually 15.0% to 25.0%) of panel(s) under ideal conditions.

Input

msg.payload can contain:

• tilt - panel(s) tilt (0.89.999)
• orientation - panel(s) orientation or azimuth (0..359.999)
• altitude - metres above sea level
• panels - number of solar panels in the array
• lat - latitude of solar array
• lon - longitude of solar array
• area - surface size of a single panel in m^2
• efficiency - panel conversion efficiency
• ts - timestamp

Output

msg.payload contains:

• timestamp: Timestamp of calculation
• powerforecast: Forecast of electrical power (in watts) generated by the system under ideal conditions.

See PV Education for details of calculation.