Add solcast support (#322)

* add solcast support

* Fix typo

* Fix solcast with single site

* Prefer "case" over "if"

* Use .env.test.local to record solcast response

* Cleanup Loop class, add test for 100% test coverage

* Fix tests by adding fake solcast config

---------

Co-authored-by: Georg Ledermann <[email protected]>

.env.example

@@ -1,6 +1,8 @@
 # Forecast.solar configuration
 # http://doc.forecast.solar/api:estimate
 
+# see .env.solcast.example for details on using solcast.com.au
+
 # latitude of location, -90 (south) … 90 (north)
 FORECAST_LATITUDE=50.123
 

.env.solcast.example

@@ -0,0 +1,29 @@
+# solcast.com configuration
+# https://toolkit.solcast.com.au/
+
+# first, create a free account on https://toolkit.solcast.com.au/ and create a "site" for your PV system
+# up to two strings are supported, both will be assigned an ID that looks like "1234-5678-9abc-def0"
+
+# use solcast
+FORECAST_PROVIDER=solcast
+
+# copy api key from solcast account
+SOLCAST_APIKEY=secret-solcast-api-key
+SOLCAST_SITE=1111-2222-3333-4444
+
+# Update interval in seconds (beware of the rate-limit!)
+FORECAST_INTERVAL=8640
+
+# for multiple strings:
+# FORECAST_CONFIGURATIONS=2
+# SOLCAST_0_SITE=1111-2222-3333-4444
+# SOLCAST_1_SITE=5555-6666-7777-8888
+
+# InfluxDB configuration
+INFLUX_HOST=eu-central-1-1.aws.cloud2.influxdata.com
+INFLUX_SCHEMA=https
+INFLUX_PORT=443
+INFLUX_TOKEN=the-secret-token-from-influxdata
+[email protected]
+INFLUX_BUCKET=my-bucket-name
+INFLUX_MEASUREMENT=Forecast

.env.test

@@ -16,3 +16,6 @@ INFLUX_TOKEN=my-token
 INFLUX_ORG=my-org
 INFLUX_BUCKET=my-bucket
 INFLUX_MEASUREMENT=my-forecast
+
+SOLCAST_APIKEY=fake-api-key
+SOLCAST_0_SITE=111-2222-3333-4444

.gitignore

@@ -1,2 +1,2 @@
-.env
+.env*
 coverage/

README.md

@@ -5,15 +5,17 @@
 
 # Forecast collector
 
-Collect solar forecast data from https://forecast.solar and push it to InfluxDB.
+Collect solar forecast data from https://forecast.solar or https://solcast.com.au and push it to InfluxDB.
 
 ## Usage
 
 1. Make sure your InfluxDB database is ready (not subject of this README)
 
 2. Prepare an `.env` file (see `.env.example`) with your InfluxDB credentials and some details about your PV plant (Geo location, azimuth, declination etc.)
 
-   You find details about the params on the [forecast.solar API documentation](https://doc.forecast.solar/api:estimate).
+   Find details about the underlying APIs here:
+   * [forecast.solar API documentation](https://doc.forecast.solar/api:estimate).
+   * [solcast API documentation](https://docs.solcast.com.au/) in the Legacy/Hobbyist section
 
 3. Run the Docker container on your Linux box:
 

Rakefile

@@ -2,7 +2,7 @@ require 'rubygems'
 require 'bundler'
 require 'rake/testtask'
 require 'dotenv'
-Dotenv.load('.env.test')
+Dotenv.load('.env.test.local', '.env.test')
 
 Rake::TestTask.new :test do |t|
   t.libs << 'test' << 'app'

app/config.rb

@@ -1,8 +1,11 @@
 Config =
   Struct.new(
+    :forecast_provider,
     :forecast_configurations,
     :forecast_solar_apikey,
     :forecast_interval,
+    :solcast_configurations,
+    :solcast_apikey,
     :influx_schema,
     :influx_host,
     :influx_port,
@@ -41,6 +44,7 @@ def validate_url!(url)
     def self.from_env(options = {})
       new(
         {}.merge(forecast_settings_from_env)
+          .merge(solcast_settings_from_env)
           .merge(influx_credentials_from_env)
           .merge(options),
       )
@@ -58,9 +62,18 @@ def self.influx_credentials_from_env
       }
     end
 
+    def self.solcast_settings_from_env
+      defaults = single_solcast_settings_from_env
+      {
+        solcast_configurations: all_solcast_settings_from_env(defaults),
+        solcast_apikey: ENV.fetch('SOLCAST_APIKEY', nil),
+      }
+    end
+
     def self.forecast_settings_from_env
       defaults = single_forecast_settings_from_env
       {
+        forecast_provider: ENV.fetch('FORECAST_PROVIDER', 'forecast.solar'),
         forecast_configurations: all_forecast_settings_from_env(defaults),
         forecast_interval: ENV.fetch('FORECAST_INTERVAL').to_i,
         forecast_solar_apikey: ENV.fetch('FORECAST_SOLAR_APIKEY', nil),
@@ -79,13 +92,27 @@ def self.single_forecast_settings_from_env
       }
     end
 
+    def self.single_solcast_settings_from_env
+      {
+        solcast_site: ENV.fetch('SOLCAST_SITE', ''),
+      }
+    end
+
     def self.all_forecast_settings_from_env(defaults)
       config_count = ENV.fetch('FORECAST_CONFIGURATIONS', '1').to_i
 
       (0...config_count).map do |index|
         ForecastConfiguration.from_env(index, defaults)
       end
     end
+
+    def self.all_solcast_settings_from_env(defaults)
+      config_count = ENV.fetch('FORECAST_CONFIGURATIONS', '1').to_i
+
+      (0...config_count).map do |index|
+        SolcastConfiguration.from_env(index, defaults)
+      end
+    end
   end
 
 ForecastConfiguration =
@@ -120,3 +147,14 @@ def self.from_env(index, defaults)
       }
     end
   end
+
+SolcastConfiguration =
+  Struct.new(
+    :site,
+  ) do
+    def self.from_env(index, defaults)
+      {
+        site: ENV.fetch("SOLCAST_#{index}_SITE", defaults[:solcast_site]),
+      }
+    end
+  end

app/forecast.rb

@@ -2,8 +2,6 @@
 require_relative 'config'
 
 class Forecast
-  BASE_URL = 'https://api.forecast.solar'.freeze
-
   def initialize(config:)
     @config = config
   end
@@ -13,9 +11,16 @@ def initialize(config:)
   def fetch_data
     hashes = []
 
-    (0...config.forecast_configurations.length).each do |index|
-      print "  #{index}: #{uri(index)} ... "
+    len =
+      case config.forecast_provider
+      when 'forecast.solar'
+        config.forecast_configurations.length
+      when 'solcast'
+        config.solcast_configurations.length
+      end
 
+    (0...len).each do |index|
+      print "  #{index}: #{uri(index)} ... "
       begin
         hashes.append(current(index))
         puts 'OK'
@@ -27,53 +32,16 @@ def fetch_data
     accumulate(hashes)
   end
 
-  private
-
-  def current(index)
-    # Change mapping:
-    #   "result": {
-    #     "watts": {
-    #       "1632979620": 0,
-    #       "1632984240": 28,
-    #       "1632988800": 119,
-    #    .....
-    #   =>
-    #   { 1632979620 => 0, 1632980640 => 28, 1632981600 => 119, ... }
-
-    forecast_response(index).dig('result', 'watts').transform_keys(&:to_i)
-  end
-
-  def uri(index)
-    URI.parse(formatted_url(index))
-  end
-
-  def base_url
-    [BASE_URL, config.forecast_solar_apikey, 'estimate'].compact.join('/')
-  end
-
-  def raw_url
-    "#{base_url}/:lat/:lon/:dec/:az/:kwp" \
-      '?damping=:damping_morning,:damping_evening' \
-      '&time=seconds'
-  end
-
-  def parameters(index)
-    cfg = config.forecast_configurations[index]
-    {
-      lat: cfg[:latitude],
-      lon: cfg[:longitude],
-      dec: cfg[:declination],
-      az: cfg[:azimuth],
-      kwp: cfg[:kwp],
-      damping_morning: cfg[:damping_morning],
-      damping_evening: cfg[:damping_evening],
-    }
-  end
-
-  def formatted_url(index)
-    raw_url.tap do |url|
-      parameters(index).each { |key, value| url.sub!(":#{key}", value) }
+  def accumulate(hashes)
+    result = hashes[0]
+    (1...hashes.length).each do |index|
+      hashes[index].each do |k, v|
+        result[k] ||= 0
+        result[k] += v
+      end
     end
+
+    result
   end
 
   def forecast_response(index)
@@ -86,16 +54,4 @@ def forecast_response(index)
       throw "Failure: #{response.value}"
     end
   end
-
-  def accumulate(hashes)
-    result = hashes[0]
-    (1...hashes.length).each do |index|
-      hashes[index].each do |k, v|
-        result[k] ||= 0
-        result[k] += v
-      end
-    end
-
-    result
-  end
 end

app/forecast_solar.rb

@@ -0,0 +1,56 @@
+require 'net/http'
+require_relative 'config'
+require_relative 'forecast'
+
+class ForecastSolar < Forecast
+  BASE_URL = 'https://api.forecast.solar'.freeze
+
+  def uri(index)
+    URI.parse(formatted_url(index))
+  end
+
+  def current(index)
+    # Change mapping:
+    #   "result": {
+    #     "watts": {
+    #       "1632979620": 0,
+    #       "1632984240": 28,
+    #       "1632988800": 119,
+    #    .....
+    #   =>
+    #   { 1632979620 => 0, 1632980640 => 28, 1632981600 => 119, ... }
+
+    forecast_response(index).dig('result', 'watts').transform_keys(&:to_i)
+  end
+
+  private
+
+  def base_url
+    [BASE_URL, config.forecast_solar_apikey, 'estimate'].compact.join('/')
+  end
+
+  def raw_url
+    "#{base_url}/:lat/:lon/:dec/:az/:kwp" \
+      '?damping=:damping_morning,:damping_evening' \
+      '&time=seconds'
+  end
+
+  def parameters(index)
+    cfg = config.forecast_configurations[index]
+    {
+      lat: cfg[:latitude],
+      lon: cfg[:longitude],
+      dec: cfg[:declination],
+      az: cfg[:azimuth],
+      kwp: cfg[:kwp],
+      damping_morning: cfg[:damping_morning],
+      damping_evening: cfg[:damping_evening],
+    }
+  end
+
+  def formatted_url(index)
+    raw_url.tap do |url|
+      parameters(index).each { |key, value| url.sub!(":#{key}", value) }
+    end
+  end
+end

app/loop.rb

@@ -3,6 +3,8 @@
 
 require_relative 'flux_writer'
 require_relative 'forecast'
+require_relative 'forecast_solar'
+require_relative 'solcast'
 
 class Loop
   def initialize(config:)
@@ -17,14 +19,17 @@ def self.start(config:, max_count: nil)
 
   def start(max_count)
     self.count = 0
-    forecast = Forecast.new(config:)
+    forecast = make_forecast
     loop do
       self.count += 1
-      puts "##{count} Fetching forecast"
+      now = DateTime.now
+      puts "##{count} Fetching forecast at #{now}"
       push_to_influx(forecast.fetch_data)
       break if max_count && count >= max_count
 
-      puts "  Sleeping for #{config.forecast_interval} seconds ..."
+      next_request = DateTime.now.to_time + config.forecast_interval
+      puts "  Sleeping for #{config.forecast_interval} seconds (until #{next_request}) ..."
+
       sleep config.forecast_interval
     end
   end
@@ -40,4 +45,13 @@ def push_to_influx(data)
     FluxWriter.push(config:, data:)
     puts 'OK'
   end
+
+  def make_forecast
+    case config.forecast_provider
+    when 'forecast.solar'
+      ForecastSolar.new(config:)
+    when 'solcast'
+      Solcast.new(config:)
+    end
+  end
 end

app/main.rb

@@ -17,7 +17,14 @@
 config = Config.from_env
 
 puts "Using Ruby #{RUBY_VERSION} on platform #{RUBY_PLATFORM}"
-puts "Pulling from api.forecast.solar every #{config.forecast_interval} seconds"
+host = case config.forecast_provider
+       when 'forecast.solar'
+         'api.forecast.solar'
+       when 'solcast'
+         'api.solcast.com.au'
+       end
+
+puts "Pulling from #{host} every #{config.forecast_interval} seconds"
 puts "Pushing to InfluxDB at #{config.influx_url}, " \
        "bucket #{config.influx_bucket}, " \
        "measurement #{config.influx_measurement}"