Class: ElectricityRate

Inherits:
Object
  • Object
show all
Defined in:
app/models/electricity_rate.rb

Overview

Per-state / per-utility electricity-rate lookups powered by the NREL
Utility Rates API. Used by the heat-loss and operating-cost calculators
on the public website to estimate "$/year to run this floor heater"
given a customer's location.

See Also:

Constant Summary collapse

US_API_URL =

See: http://developer.nrel.gov/docs/electricity/utility-rates-v3/ for API details

'https://developer.nrel.gov/api/utility_rates/v3.json'.freeze
US_API_KEY =

Key used for us api.

'pNYthBjsnd8WKS85K9qkg6mkZ2gISU6iPchwqdKi'.freeze
CAN_RATE_BY_PROVINCE =

Updated December 2025
Source: https://offgridsolarsystem.ca/blog/Canada-electricity-rates.html (July 2025)
IMPORTANT: These are MARGINAL rates (Tier 2 / Step 2) for provinces with tiered pricing.
Floor heating is additive consumption, so customers pay the higher tier rate, not the blended average.

  • BC: Step 2 rate (14.08¢) used instead of Step 1 (11.72¢)
  • QC: Tier 2 rate (10.7¢) used instead of blended average (7.8¢) per Hydro-Québec Rate D
  • ON: Mid-peak TOU rate (15.7¢) used as representative rate for additional heating load
{
  'AB' => 0.258,  # Alberta - includes delivery & admin charges
  'BC' => 0.141,  # BC Hydro Step 2 rate (14.08¢ rounded)
  'MB' => 0.102,  # Manitoba Hydro
  'NB' => 0.139,  # NB Power
  'NL' => 0.148,  # NL Hydro / Newfoundland Power
  'NS' => 0.183,  # Nova Scotia Power
  'NT' => 0.410,  # NTPC (high due to diesel generation)
  'NU' => 0.354,  # Qulliq Energy Corp
  'ON' => 0.157,  # Ontario - mid-peak TOU rate (Nov 2025)
  'PE' => 0.184,  # Maritime Electric
  'QC' => 0.110,  # Hydro-Québec Tier 2 rate (~10.7¢)
  'SK' => 0.199,  # SaskPower
  'YT' => 0.187   # Yukon Energy / ATCO Electric
}.freeze
US_RATE_BY_STATE =

https://www.saveonenergy.com/electricity-rates/electricity-rates-by-state/ as of 12/2024, updated 3/4/2025

{
  'AL' => 0.1491,
  'AK' => 0.2238,
  'AZ' => 0.1520,
  'AR' => 0.1174,
  'CA' => 0.3055,
  'CO' => 0.1516,
  'CT' => 0.2816,
  'DE' => 0.1668,
  'DC' => 0.1626, # This one i don't know it's not from that table, i used the average
  'FL' => 0.1420,
  'GA' => 0.1349,
  'HI' => 0.4234,
  'ID' => 0.1097,
  'IL' => 0.1599,
  'IN' => 0.1442,
  'IA' => 0.1243,
  'KS' => 0.1385,
  'KY' => 0.1328,
  'LA' => 0.1170,
  'ME' => 0.2629,
  'MD' => 0.1815,
  'MA' => 0.3122,
  'MI' => 0.1841,
  'MN' => 0.1405,
  'MS' => 0.1344,
  'MO' => 0.1157,
  'MT' => 0.1187,
  'NE' => 0.1078,
  'NV' => 0.1488,
  'NH' => 0.2362,
  'NJ' => 0.1949,
  'NM' => 0.1426,
  'NY' => 0.2437,
  'NC' => 0.1349,
  'ND' => 0.1021,
  'OH' => 0.1598,
  'OK' => 0.1152,
  'OR' => 0.1412,
  'PA' => 0.1760,
  'RI' => 0.2531,
  'SC' => 0.1387,
  'SD' => 0.1241,
  'TN' => 0.1304,
  'TX' => 0.1542,
  'UT' => 0.1102,
  'VT' => 0.2229,
  'VA' => 0.1446,
  'WA' => 0.1183,
  'WV' => 0.1451,
  'WI' => 0.1631,
  'WY' => 0.1178
}.freeze
ALL_STATES_AND_PROVINCES =

All states and provinces.

CAN_RATE_BY_PROVINCE.merge(US_RATE_BY_STATE).freeze
CAN_AVERAGE_RATE =

Canadian average rate - used as fallback when province cannot be determined.
This is a weighted average biased toward Tier 2/marginal rates to better reflect
the cost of additional consumption like floor heating.
Updated December 2025 based on provincial rates above.

0.175
US_AVERAGE_RATE =

US average rate - updated March 2025
Source: https://www.saveonenergy.com/electricity-rates/electricity-rates-by-state/

0.1626
RATES_BY_COUNTRY =

Rates by country.

{
  'USA' => US_AVERAGE_RATE,
  'CAN' => CAN_AVERAGE_RATE
}.freeze
RATES_BY_COUNTRY_ISO =

Rates by country iso.

{
  'US' => US_AVERAGE_RATE,
  'CA' => CAN_AVERAGE_RATE
}.freeze
POSTAL_CA_REGEXP =

This regexp can handle regional postal code as well as full canadian postal codes

/^([ABCEGHJ-NPRSTVXY]\d[ABCEGHJ-NPRSTV-Z])([ -]?\d[ABCEGHJ-NPRSTV-Z]\d)?$/i
POSTAL_US_REGEXP =

This one handles US with +4 optional

/^(\d{5})(-{0,1}\d{4})?$/

Class Method Summary collapse

Class Method Details

.get_average_for_locale(locale = I18n.locale) ⇒ Object 



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# File 'app/models/electricity_rate.rb', line 204

def self.get_average_for_locale(locale = I18n.locale)
  country_iso = locale.to_s.last(2)
  RATES_BY_COUNTRY_ISO[country_iso]
end

.get_average_rate_for_country_iso_state_code(country_iso, state_code) ⇒ Object 



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# File 'app/models/electricity_rate.rb', line 121

def self.get_average_rate_for_country_iso_state_code(country_iso, state_code)
  {
    'US' => US_RATE_BY_STATE,
    'CA' => CAN_RATE_BY_PROVINCE
  }[country_iso]&.dig(state_code)
end

.get_average_rate_for_locale(locale = I18n.locale) ⇒ Object 



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# File 'app/models/electricity_rate.rb', line 128

def self.get_average_rate_for_locale(locale = I18n.locale)
  case LocaleUtility.locale_to_country_iso(locale)
  when 'US'
    US_AVERAGE_RATE
  when 'CA'
    CAN_AVERAGE_RATE
  end
end

.get_average_rate_for_locale_as_money(locale = I18n.locale) ⇒ Object 



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# File 'app/models/electricity_rate.rb', line 137

def self.get_average_rate_for_locale_as_money(locale = I18n.locale)
  case LocaleUtility.locale_to_country_iso(locale)
  when 'US'
    Money.from_amount(US_AVERAGE_RATE, 'USD')
  when 'CA'
    Money.from_amount(CAN_AVERAGE_RATE, 'CAD')
  end
end

.get_by_lat_lng(lat, lng) ⇒ Object 



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# File 'app/models/electricity_rate.rb', line 209

def self.get_by_lat_lng(lat, lng)
  get_from_location([lat, lng], :coordinates)
end

.get_from_location(location, search_type) ⇒ Object 



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# File 'app/models/electricity_rate.rb', line 162

def self.get_from_location(location, search_type)
  res = {}
  res[:location] = location
  res[:search_type] = search_type

  # Try to find location with state code first
  geo = Geocoder.search(location).find { |g| g.country_code.present? && g.state_code.present? }
  # Fall back to just country if no state code
  geo ||= Geocoder.search(location).find { |g| g.country_code.present? }

  if geo
    iso_country = ISO3166::Country[geo.country_code]
    res[:country_iso3] = iso_country&.alpha3
    res[:country_iso] = iso_country&.alpha2
    res[:currency_code] = iso_country&.currency_code || 'USD'
    res[:state_code] = geo.state_code
    res[:postal_code] = geo.postal_code if geo.respond_to?(:postal_code)

    # Try state/province rate first, then country rate
    res[:average_rate] = ALL_STATES_AND_PROVINCES[res[:state_code]] if res[:state_code]
    if res[:average_rate]
      res[:precision] = :state_or_province
    elsif (res[:average_rate] = RATES_BY_COUNTRY_ISO[res[:country_iso]])
      res[:precision] = :country
    end
  end

  if res[:average_rate]
    # Money is expressed in the destination country value
    rate_money = Money.from_amount(res[:average_rate], res[:currency_code])
    res[:currency] = rate_money.currency.iso_code
    res[:currency_symbol] = rate_money.currency.symbol
    res[:status] = :ok
  else
    # Return OK with no rate - let the client keep its current value
    res[:status] = :ok
    res[:message] = 'No electricity rate data available for this location'
    res[:average_rate] = nil
  end
  res
end

.get_from_postal_code(code) ⇒ Object

Some test code
J9X4M2 - Quebec
60047 - Lake Zurich
J9X%204M2 - Poorly formatted postal code
J9X region code



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# File 'app/models/electricity_rate.rb', line 151

def self.get_from_postal_code(code)
  require 'cgi'
  clean_code = CGI.unescape(code)
  # Scan for canadian first
  postal_code = clean_code.to_s.scan(POSTAL_CA_REGEXP).join.presence&.upcase
  # For US zips, only use the 5-digit base (strip +4 suffix) since Geocoder doesn't handle ZIP+4
  postal_code ||= clean_code.to_s.match(POSTAL_US_REGEXP)&.captures&.first
  Rails.logger.debug { "ElectricityRate: Looking up postal code #{postal_code}" }
  get_from_location("#{postal_code}, North America", :postal_code) # patch pending more thorough international support top avoid, for e.g., an IA zip code being returned as Kuala Lumpur
end