Bugger all solar predicted for today, so the battery is charging while electricity prices are cheap.
About 20p/kWh right now. Jumping to 50p later this evening.
@Edent this feels like something you could price out in battery cycles/projected degradation vs rate history - any idea what the break even point will be?
@Orb2069
It is, of course, complicated.
Our battery was a bit under £3k.
If it can save £1 per day, it'll break even in about 8 years.
If electricity prices go up, break even comes down.
It is guaranteed for 7 years of cycles - but properly managed batteries seem to exceed that.
@Edent It might be worth pondering how much the Demand Flexibility Service ("Octoplus") service is worth, and how much dumping at peak is worth vs the affect on your average (Baseline) figure. (Based in the last 10 recorded non-scheme days)
We're not in peak DFS season at present, but the DFS payouts are £2.25/kWh for both reduction vs baseline and export.
@Edent Congratulations! I use a radiator convection heater instead of using the natural gas furnace. I save a lot of money although I don't have a specific dollar amount.
@steveworkman it's a Moixa battery. It automatically reads the energy prices from the Octopus API and sets a charging schedule based on my predicted usage.
No manual intervention.
@Edent I might try removing some grid lines before making the plot line thicker, esp the vertical lines, perhaps reduce to hourly increments or even 3 or 6 hourly. Also, if you do choose to shade the area under the line you could use white horizontal lines over that area in preference to the horizontal grid lines.
@Edent mind if I ask what the eink screen is you're using? I've got a hankering to do some in-home display stuff, so looking at options for eink and other panels.
@Edent nice. I'd have to go battery-only at least initially due to planning permission (I'm in an unfathomably classified heritage area), which would require 29 recharage/discharge cycles per month of a 9kwh battery costing £6k with a 7p kwh dip and 45p kwh peak to break even in 5 years.
@Edent this looks awesome. I have been wondering how beneficial solar panels would be given UK weather but never thought about being able to charge the battery during off peak hours.
@Edent what are you planning for control of when to charge? I have a Home Assistant AppDaemon script which I’ve been using to control a Growatt inverter. It’s early days yet but seems to be working well. I’d be happy to share.
@boffbowsh
My battery manages it all for me automatically. It has a built in sensor to see how much in importing or exporting, it knows the prices and weather forecast. So no need for manual intervention.
@Edent Also interested in how you get on. We have a solar PV array and a battery, but are just on the SV Octopus tariff for import and Outgoing Octopus for export.
@billgoats Based on my back-of-a-fag-packet calculations, we should be able to offset some of our usage.
Ideally, charge up the battery overnight, use solar in the day, discharge at the evening peak.
If you haven't seen already, you might be interested in Intelligent Octopus Go (EV charging) or Intelligent Octopus Flux (Battery & Solar) which optimise the assets for you 🙂 Compatible car/battery/inverter required, however.
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