Backyard solar
Cheap solar project to offset quiescent energy use when the house is unoccupied and there are no other useful options for using the energy.
e.g. hot water good, no car charging, no lights, towel rails, washing, drying etc
Hardware
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Shelly EM version 1 - Underpower URL is set so when load is below 25 Watts the Node-Red flow (See Kick Dump.js (986 Bytes) is kicked to regulate the Dump Load Dimmer switch.
***var absdp = Math.abs(ShellyEM - DumpDeadBand);
DumpPower += (absdp * DumpPgain);
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Two Hubitat Elevation C7 hubs
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eWeLink CUBE running Node-Red in Docker. Seems quite good at more math intensive cyclical workloads. Keeps Hubitat load low and more responsive.
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Dual 100W channel dimmer both in parallel driving a 280W heat lamp. Stays perfectly cool at full power with heat sink added to Triac’s
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AliExpress part Tuya Dimmer Hacked a Hubitat community driver by “Matt Hammond” to get it working with the _TZ3000_kvwrdf47
def cfg = [" _TZ3000_kvwrdf47": [ numEps: 2, joinName: “Tuya Zigbee 2-Gang Dimmer module” ]]
See Greenway Tuya Zigbee dimmer module.groovy (16.2 KB)
Function
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Stop solar export in low load situations, which does happen when the house is unoccupied
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The 2 second update
You can see in the above the dump load a $5 lamp regulates the load so I DON"T export hardly any power.
We produced 2.065kWh dumping 0.255kWh with a single panel generating 371 Watts peak so far today we have only exported 2.4 Watt out of 2.065kWh generated