Nordpool electricity - Printable Version

Code:
-------------------------------------------------

-- PRICE CALCULATION -Change these

-------------------------------------------------

vat        = 1.255

marginal  = 0.42

electricity_tax = 2.82752

night_tariff = 0.89

day_tariff = 1.87



function add_costs(base_price, hour)

  local tariff



  -- Night tariff 22:00–07:00

  if hour >= 22 or hour < 7 then

    tariff = night_tariff

  else

    tariff = day_tariff

  end



  return base_price * vat + marginal + tariff + electricity_tax

end



https = require('ssl.https')

json = require('json')

ltn12 = require('ltn12')



country = 'fi'



current_price_addr        = '35/5/12'

cheapest_hour_addr        = '35/5/13'

cheapest_hour_price_addr  = '35/5/14'

costliest_hour_addr       = '35/5/15'

cosltiest_hour_price_addr = '35/5/16'



-------------------------------------------------

-- Helper: format numbers to "xx.xx snt"

-------------------------------------------------

-- Format for KNX (string with unit)

local function fmt2s(x)

  if type(x) ~= "number" then return x end

  return string.format("%.3f snt", x)

end



-- Format for storage (pure number)

local function fmt2num(x)

  if type(x) ~= "number" then return x end

  return tonumber(string.format("%.5f", x))

end



-------------------------------------------------

-- DATE SETUP

-------------------------------------------------

local current_date = os.date('*t')



local day_start_ts = os.time({

  year  = current_date.year,

  month = current_date.month,

  day   = current_date.day,

  hour  = 0, min = 0, sec = 0

})

local day_end_ts = day_start_ts + 24 * 3600



local tomorrow_start_ts = day_start_ts + 24 * 3600

local tomorrow_end_ts   = tomorrow_start_ts + 24 * 3600



local current_ts = os.time()



-------------------------------------------------

-- FETCH DATA

-------------------------------------------------

local previous_date = os.date('%F', os.time() - 24 * 3600)

local next_date     = os.date('%F', os.time() + 24 * 3600)



local url =

  'https://dashboard.elering.ee/api/nps/price?start=' ..

  previous_date .. 'T21%3A00%3A00Z&end=' ..

  next_date .. 'T23%3A59%3A59Z'



local mac = 0

io.readfile('/sys/class/net/eth0/address'):gsub('%x%x', function(v)

  mac = mac * 256 + tonumber(v, 16)

end)



local response = {}

local res, code = https.request({

  url = url,

  protocol = 'tlsv12',

  headers = { ['user-agent'] = 'LM ' .. mac },

  sink = ltn12.sink.table(response)

})



if not (res and code == 200) then

  log('request error', res, code)

  return

end



local data = json.pdecode(table.concat(response))

if not data or not data.data or not data.data[country] then

  log('No data for country: ' .. country)

  return

end



-------------------------------------------------

-- PROCESS TODAY + TOMORROW

-------------------------------------------------

local hourly_prices_today = {}

local today_hours = {}

local tomorrow_entries = {}



for h = 0, 23 do

  hourly_prices_today[h] = { sum = 0, count = 0 }

end



for _, record in ipairs(data.data[country]) do

  local timestamp = record.timestamp

  local lt = os.date('*t', timestamp)

  local hour = lt.hour

  local price = add_costs(record.price * 0.1, hour)



  -- TODAY

  if timestamp >= day_start_ts and timestamp < day_end_ts then

    local d = hourly_prices_today[hour]

    d.sum = d.sum + price

    d.count = d.count + 1

  end



  -- TOMORROW (15-min entries)

  if timestamp >= tomorrow_start_ts and timestamp < tomorrow_end_ts then

    tomorrow_entries[#tomorrow_entries + 1] = {

      timestamp = timestamp,

      price = price

    }

  end

end



-------------------------------------------------

-- CURRENT PRICE

-------------------------------------------------

do

  local ch = tonumber(os.date('%H', current_ts))

  local d = hourly_prices_today[ch]

  if d and d.count > 0 then

    grp.write(current_price_addr, d.sum / d.count)

  end

end



-------------------------------------------------

-- TODAY HOURLY AVERAGES

-------------------------------------------------

for h = 0, 23 do

  local d = hourly_prices_today[h]

  if d.count > 0 then

    today_hours[h+1] = d.sum / d.count

  else

    today_hours[h+1] = "Ei hintaa"

  end

end



-- WRITE TODAY → 35/6/0..23 (numeric)

for h = 0, 23 do

  grp.checkwrite('35/6/' .. h, today_hours[h+1])

end



-------------------------------------------------

-- TOMORROW: 15-min → hourly

-------------------------------------------------

local tomorrow_segments = {}



do

  local total_quarters = #tomorrow_entries

  local full_segments = math.floor(total_quarters / 4)



  for seg = 0, full_segments do

    local base = seg * 4 + 1

    if tomorrow_entries[base + 3] then

      local ts = tomorrow_entries[base].timestamp

      local h = os.date('*t', ts).hour



      local s = 0

      for j = base, base + 3 do

        s = s + tomorrow_entries[j].price

      end



      tomorrow_segments[#tomorrow_segments + 1] = {

        hour = h,

        price = s / 4

      }

    end

  end

end



local seg_count = #tomorrow_segments

local tomorrow_hours_stored = {}



-------------------------------------------------

-- WRITE TOMORROW → 35/7/0..23 (STRING "xx.xx snt")

-------------------------------------------------

for h = 0, 23 do

  local seg_idx = nil



  if seg_count == 24 then

    seg_idx = h + 1

  elseif seg_count == 23 then

    if h <= 2 then seg_idx = h + 1

    elseif h == 3 then seg_idx = nil

    else seg_idx = h end

  elseif seg_count == 25 then

    if h <= 2 then seg_idx = h + 1

    elseif h == 3 then seg_idx = 4

    else seg_idx = h + 2 end

  else

    if h + 1 <= seg_count then seg_idx = h + 1 end

  end



  local value = "Ei hintaa"

  if seg_idx and tomorrow_segments[seg_idx] then

    value = fmt2s(tomorrow_segments[seg_idx].price)

  end



  grp.checkwrite('35/7/' .. h, value)

  tomorrow_hours_stored[h+1] = value

end



-------------------------------------------------

-- DST EXTRA HOUR → 35/7/25

-------------------------------------------------

if seg_count == 25 and tomorrow_segments[5] then

  grp.checkwrite('35/7/25', fmt2s(tomorrow_segments[5].price))

else

  grp.checkwrite('35/7/25', "Ei hintaa")

end



-------------------------------------------------

-- DAY AFTER TOMORROW FIRST HOUR → 35/7/24

-------------------------------------------------

local day_after_tomorrow_price = "Ei hintaa"



do

  local start_ts = tomorrow_end_ts

  local end_ts = tomorrow_end_ts + 3600



  local sum = 0

  local count = 0



  for _, record in ipairs(data.data[country]) do

    local ts = record.timestamp

    if ts >= start_ts and ts < end_ts then

      local lt = os.date('*t', ts)

      local p = add_costs(record.price * 0.1, lt.hour)

      sum = sum + p

      count = count + 1

    end

  end



  if count > 0 then

    day_after_tomorrow_price = fmt2s(sum / count)

  end

end



grp.checkwrite('35/7/24', day_after_tomorrow_price)