(06.10.2025, 12:51)RomansP Wrote: Hi!

We have rewritten script (old script will not work properly), because of a change
in time intervals (previously electricity price was per hour, now per 15 minutes).

Here is a new script:

Code:

https = require('ssl.https')
json = require('json')
ltn12 = require('ltn12')

country = 'lv' -- Latvia
--country = 'fi' -- Finland
--country = 'lt' -- Lithuania
--country = 'ee' -- Estonia

current_price_addr = '40/1/18'
cheapest_hour_addr = '40/1/16'
cheapest_hour_price_addr = '40/1/17'
costliest_hour_addr = '40/1/19'
cosltiest_hour_price_addr = '40/1/20'
cheapest_time_addr = '40/1/14'
cheapest_price_addr = '40/1/15'
costliest_time_addr = '40/1/21'
costliest_price_addr = '40/1/22'

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 = os.time({year = current_date.year, month = current_date.month, day = current_date.day, hour = 23, min = 59, sec = 59})
local current_ts = os.time()

previous_date = os.date('%F', os.time() - 24*60*60)
next_date = os.date('%F', os.time() + 24*60*60)

url = 'https://dashboard.elering.ee/api/nps/price?start='.. previous_date ..'T00%3A00%3A00.999Z&end=' .. next_date ..'T00%3A00%3A00.999Z'

mac = 0
io.readfile('/sys/class/net/eth0/address'):gsub('%x%x', function(v)
  mac = mac * 256 + tonumber(v, 16)
end)

response = {}
res, code = https.request({
  url = url,
  protocol = 'tlsv12',
  headers = {
    ['user-agent'] = 'LM ' .. mac
  },
  sink = ltn12.sink.table(response)
})

if res and code == 200 then
  data = json.pdecode(table.concat(response))
else
  log('request error', res, code)
  return
end


min_price = 99999
max_price = -1
min_price_timestamp = 0
max_price_timestamp = 0
current_price = nil


hourly_prices = {}
for h = 0, 23 do
  hourly_prices[h] = { sum = 0, count = 0 }
end

if not data or not data.data or not data.data[country] then
  log('No data for country: ' .. country)
  return
end

for _, record in ipairs(data.data[country]) do
  local timestamp = record.timestamp
  local price = record.price

  if timestamp >= day_start_ts and timestamp <= day_end_ts then
   
    if price < min_price then
      min_price = price
      min_price_timestamp = timestamp
    end
   
    if price > max_price then
      max_price = price
      max_price_timestamp = timestamp
    end

    local record_time = os.date('*t', timestamp)
    local hour = record_time.hour
    if hourly_prices[hour] then
      hourly_prices[hour].sum = hourly_prices[hour].sum + price
      hourly_prices[hour].count = hourly_prices[hour].count + 1
    end
  end
 
  if current_ts >= timestamp and current_ts < (timestamp + 15 * 60) then
    current_price = price
  end
end

--log('--- Current Status ---')
if current_price then
  --log('Current 15-min price: ' .. current_price .. ' EUR/MWh')
  grp.write(current_price_addr, current_price) -- float
else
  log('Could not determine current price')
end


min_avg_price = 99999
max_avg_price = -1
cheapest_hour = -1
costliest_hour = -1

for hour, data in pairs(hourly_prices) do
  if data.count > 0 then
    local avg_price = data.sum / data.count
    --log(string.format("Hour %02d:00 - Avg Price: %.2f", hour, avg_price))
   
    if avg_price < min_avg_price then
      min_avg_price = avg_price
      cheapest_hour = hour
    end

    if avg_price > max_avg_price then
      max_avg_price = avg_price
      costliest_hour = hour
    end
  end
end

cheapest_hour_time = {}
cheapest_hour_time['wday'] = current_date['wday']

--log('--- Cheapest Hour Today ---')
if cheapest_hour ~= -1 then
  --log(string.format('Hour: %02d:00 - %02d:59', cheapest_hour, cheapest_hour))
  --log(string.format('Average Price: %.2f EUR/MWh', min_avg_price))
  cheapest_hour_time['hour'] = cheapest_hour
  grp.write(cheapest_hour_addr, cheapest_hour_time)
  grp.write(cheapest_hour_price_addr, min_avg_price)
else
  log('Could not calculate the cheapest hour.')
end

costliest_hour_time = {}
costliest_hour_time['wday'] = current_date['wday']

--log('--- Costliest Hour Today ---')
if costliest_hour ~= -1 then
  --log(string.format('Hour: %02d:00 - %02d:59', costliest_hour, costliest_hour))
  --log(string.format('Average Price: %.2f EUR/MWh', max_avg_price))
  costliest_hour_time['hour'] = costliest_hour
  grp.write(costliest_hour_addr, costliest_hour_time)
  grp.write(cosltiest_hour_price_addr, max_avg_price)
else
  log('Could not calculate the costliest hour.')
end

cheapest_time = {}
cheapest_time['wday'] = current_date['wday']

--log('--- Cheapest 15-min Interval Today ---')
if min_price_timestamp > 0 then
  local min_price_time = os.date('*t', min_price_timestamp)
  --log('Price: ' .. min_price .. ' EUR/MWh')
  --log('Time: ' .. string.format('%02d:%02d', min_price_time.hour, min_price_time.min))
  cheapest_time['hour'] = min_price_time.hour
  cheapest_time['minute'] = min_price_time.min
  grp.write(cheapest_time_addr, cheapest_time)
  grp.write(cheapest_price_addr, min_price)
else
  log('Could not find minimum price for today')
end

costliest_time = {}
costliest_time['wday'] = current_date['wday']

--log('--- Costliest 15-min Interval Today ---')
if max_price_timestamp > 0 then
  local max_price_time = os.date('*t', max_price_timestamp)
  --log('Price: ' .. max_price .. ' EUR/MWh')
  --log('Time: ' .. string.format('%02d:%02d', max_price_time.hour, max_price_time.min))
  costliest_time['hour'] = max_price_time.hour
  costliest_time['minute'] = max_price_time.min
  grp.write(costliest_time_addr, costliest_time)
  grp.write(costliest_price_addr, max_price)
else
  log('Could not find maximum price for today')
end