Tool or service to calculate cost savings?

[sorka]

Is there a tool out there that can import monitoring data and calculate the difference in cost based on total how usage and provide costs if you'd just taken that power off the grid at the time it was used vs what it's actually costing because of solar and time shifting using storage?

It would also need to keep track of what's been fed back to the grid based on TOU rates at that time.

Can Grafana do this? Another tool? Will the API give me the raw data in case I just need to go write my own dashboards in Splunk?

 

[getakey]

you can get pretty close by just taking the TOU rate difference between Off Peak and Peak and multiple by number of kWh you can pull from batteries during Peak. Summer will be different rates than winter. In my case, I am saving ~$7/day in Summer

 

[vickh]

I'm looking for something similar too. I'm only getting 9-10kwh/day and paying $50/mo. here in AZ for a rental. Debating whether I'll continue next year if this continues.

 

[jjrandorin]

I'm looking for something similar too. I'm only getting 9-10kwh/day and paying $50/mo. here in AZ for a rental. Debating whether I'll continue next year if this continues.

Production from Nov - February will be 1/2 or a bit less than half of production from april - june. You likely need to base your decision on a full year of usage, not a few months, especially winter months.

 

[sorka]

So all I really need at a minimum is the house usage since that's all I need to calculate what it WOULD cost me without solar or storage. I can then compare that to my actual PG&E costs over time.

Is there a REST API that will I can use to query house usage? I can get it now by downloading the daily csv data from the app but I won't do that manually every day. Really need an API that I can get hourly home use data for. I could then write a splunk plugin to pull that data daily or whatever makes sense based on the API format and keep a dashboard of what it would have cost using my EV-2A schedule without solar or powerwall.

Can Grafana be customized to do this already?

 

[cwied]

Grafana is just the dashboard tool. I think what you're looking for is influxdb. You can set up telegraf to log the Powerwall statistics into influxdb and then query for the hourly data using influxdb's REST API: InfluxDB API reference | InfluxDB v1.8 Documentation

 

[cwied]

FWIW, here's an example query that would give me today's hourly usage in kWh using my setup:
SELECT (last("load_energy_imported") - first("load_energy_imported"))/1000 FROM "raw"."http" WHERE time >= 1604304000000ms and time <= 1604390399999ms GROUP BY time(1h) tz('US/Pacific')

Applying a TOU rate schedule would probably be possible, but that would require using the newer Flux query language instead of the old InfluxDB query syntax. It would be difficult to handle monthly rate tiers just in a query.