It is arguable that meter data isn't a good fit for RDF and SPARQL. Given a conservatively estimated hundred meters with half-hourly readings you're looking at 4800 readings a day, and at ~5 triples per reading you're at 8 million triples per year.
Compounding the problem is the difficulty of retrieving data for date ranges, as this would require custom indexing in one's query processor.
We define a meter:Meter, which is a physical metering device. In most cases we don't care or know about them.
We also have a meter:MeterPoint, which is the concept of