Solar PV inverters often have their own web-based monitoring solutions. However some of these do not make it easy to view current generation or consumption due to refresh delays. Out of the box monitoring is usually good for looking at long-term time periods however lacks the granularity to see consumption of appliances over the short term.
Realtime monitoring of Solar generation and net export helps to maximise self-consumption. For example coordinating appliances to make best use of solar PV.
Existing inverter monitoring does not show granular data over recent history – for example, to be able to tell when a dishwasher has finished its heating cycle and whether another high-consumption appliance should be turned on:
This sample android application allows realtime monitoring whilst charting consumption, generation and net export:
The chart shows recent data over time and is configurable for SMA and Enphase inverters. In both cases the local interface of each inverter is used to pull raw data:
Electricity retailers sometimes give the choice of paying a flat rate for electricity, or so called Time of Use (ToU) rate. Time of use pricing usually has peak, off-peak and shoulder prices. This can also vary by time of year and also weekend or weekday.
For the consumer, Time of Use pricing may be beneficial if consumption can be shifted to off-peak hours, but this is potentially offset by more expensive rates during peak times.
Assuming a retailer gives the ability to choose – which one is cheaper?
This web calculator gives the ability to simulate costs based on historical meter data usage and configurable pricing and peak/off-peak definition:
For this demo, home solar PV generation data has been obtained from United Energy’s Energy Easy portal in CSV format. For the sake of convenience in dealing with the raw data which usually comes in half-hourly intervals, this data has been loaded in to a Pentaho data warehouse instance (more details in a later post, perhaps!) and converted to day-by-day figures.
Analysis can help explore whether solar panels are getting less efficient over time, or even determine what a “good” day of production is like in summer vs winter (by looking at the relevant frequency of each in the histogram).
Drag and scroll date region which affects histogram above:
Changeable histogram buckets:
Snap-shotting of one selected date range for visual comparison with another (e.g. summer vs winter comparison):