Timeline for Equipment to throttle energy consumption of 220V AC device (Solar+grid)
Current License: CC BY-SA 4.0
8 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Jul 27, 2023 at 7:13 | comment | added | bobflux | No that won't work, if solar produces 500W and the load draws 1000W, on/off control like this will result in periods being billed for 500W import when on, and 500W export when off. | |
| Jul 26, 2023 at 23:00 | comment | added | Harper - Reinstate Monica | OK well then nothing more to it, you can just have a contactor and a timer that runs your water heater for 30 seconds every 5 minutes. Heck I would just use a triac, and hold it gate full on for the entire 30 seconds. (so no wave shaping). | |
| Jul 26, 2023 at 20:28 | comment | added | bobflux | If you use a duty cycler which passes complete periods, then it won't work, because on the periods it's on, it will import, and on the periods it's off, it will export, and these end up in two different counters that do not cancel. Pretty much everyone around here who does solar found out the hard way lol. If it averaged power over a reasonable duration like one second then it would be possible to use a duty cycler, which would be a better option, cheaper and cleaner. | |
| Jul 26, 2023 at 20:25 | comment | added | bobflux | They do run separate counters for import and export. Energy is counted per-period, and at the end of the period, depending on sign, the period's energy is added to import counter or export counter. There is no other way to handle reactive power, which flows back and forth every period yet is not billed. If it worked as you say, within the period, then every X capacitor in the house would be metered as importing power during half the period then exporting power the other half! | |
| Jul 26, 2023 at 19:17 | comment | added | Harper - Reinstate Monica | Citation needed on that, I think. I'm fairly sure they run two separate tallies for energy export and energy import, within that period. If what you say is so, OP doesn't even need a dimmer, just a duty cycler that runs the water heater 6 seconds out of every minute (or 10% of the interval measured by the meter). That wouldn't make much noise. One way to find out! | |
| Jul 26, 2023 at 19:02 | comment | added | bobflux | Smartmeters measure and bill energy per-period. Otherwise it would not be possible to bill only active power and not reactive power. So yes indeed, oldskool phase cut dimming will absolutely work with non net metering. Makes a ton of noise though. | |
| Jul 26, 2023 at 18:37 | comment | added | Harper - Reinstate Monica | The dimmer won't work. The problem is time. When the triac is gated off, all the solar will export to the utility. When the triac is gated on, all the solar will go to the water heater and it will draw the remainder from the utility. And OP does not have net metering, that being the entire issue at hand! | |
| Jul 26, 2023 at 15:11 | history | answered | bobflux | CC BY-SA 4.0 |