No There is no provision for individual IoTaWatt to combine their local datalogs. You would need to use one of the data upload services to send it to an external database.
I’m pretty sure you can do this with Emoncms, but I saw where they gave you short-shrift as is customary over there if you mention IoTaWatt. Their product line often results in multiple “nodes” reporting data that is combined. But you are now officially in the outcast group that cannot get answers to any questions because you have an IoTaWatt. I’m running into more and more folks that get their IoTaWatt running very quickly then run into a wall trying to understand Emoncms. Sad.
But moving on, I’d recommend you look into sending your data to an instance of influxDB. That is becoming very popular with IoTaWatt users and uploading is fully supported. You will need to establish an instance of influxDB, and one of several reporting and visualization packages available like grafana.
I’d prefer that some of the more knowledgeable users here on this forum take a few minutes to help you with this if you can’t find what you need on the internet.
Another approach might be to reduce the number of inputs that you need to 14. I don’t know how many circuits you have, but there are ways to combine multiple circuits into a single IoTaWatt input. You can pass multiple conductors through a single CT and/or combine multiple CTs together into one input using a simple commodity headphone splitter. I’m currently revamping the documentation site and will have a section on how to do that soon. With a single IoTaWatt, you can upload your generation and consumption to PVoutput, which is a simple, reliable and free service to handle PV output vs generation data.
There is also the possibility that you could get larger CTs that are designed to go on bussbars.