In addition to tracking electric consumption I also graph cost as this is more meaningful to the rest of the family. We are switching to Octopus where they have a variable tariff that is billed in 1/2 sessions all different. The billing rates are set the previous day some time after 16:00 UTC when the wholesale electricity generation auction has taken place. The rates are available for download and I have set up a node-red flow to get them as a json object.
Is it possible to combine this with the consumption as logged by emoncms to produce a daily cost?
If so any thought on the best/simplest way to achieve this?
I will continue to calculate the daily cost of the fixed tariff so we can see if the variable tariff does in fact save us money. We will do our best to make use of the lowest cost periods which will be predictable. I am already (with help from others) setting up a node red flow that will switch sonoff sockets and relays so we can run the dishwasher, washing machine and tumble dryer at least cost. We will also add in battery charging which will be added at some time as with solar charging and low tariff charging this becomes more attractive.
If any one else is thinking of switching to Octopus send me a PM and I can provide a link that gives £50 credit on sign up.