Needs to start a smart airco system on surplus solar power

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1

Hallo,

I want to start a smart control system for my airco Mitsubishi, with 1 multi-split MXZ2F53VF4 unit and 2 inner units MSZ-EF18VGKW and MSZ-EF50VGKW both with integrated WiFi.

They will be installed soon.

I have already “Homewizard app” with P1 meter to read the solar current.

I want to run the airco using the surplus solar power. (cooling in summer and heating in the spring and autumn.

What else do I need and how do I get started?

BR

marc

2

Make sure you install the MelCloud integration for Mitshubishi. Once done you can use automations to trigger based on the P1 meter values.

3

Sounds simple. It may not be.

You’ll need to know when you’re generating excess solar. This will require at least three energy monitoring channels: solar generated, energy being exporting, energy being consumed by the HVAC unit. I’ll reference Open Energy Monitor here.

Under what conditions would the HVAC unit be turned on? When there is an excess? When there is sufficient excess if you know what the HVAC is going to require? And off? When you are importing?

If the HVAC is on and a light is turned on, this may put you into importing, but shortly there after, the light is turned off. How would are transients handled?

How is the comfort vs efficiency to be handled?

Can the energy consumption of the HVAC unit be controlled?

I’ve considered a scenario like the following because I’m on net metering. When I have exported sufficient energy to run the HVAC for 1 hour, I turn on the HVAC. After and hour, I determine the energy exported during that hour. If energy was exported, I continue to run the HVAC for a time that is proportionate to the energy exported. After that time, I redo the calculation and continue to run the HVAC or turn it off for the rest of the day.

In my area we have Time-of-Use metering. Exported energy is “stored” as dollars, meaning if I generate 3kW during the off-peak period, I get back 1kW during on-peak period. Consideration for crossing into another time period should be made.

In my opinion, what you need to get started is a clear understanding of what you’re trying to do. Though, setting up a system that has most of the major elements and then after running for a while, modifying the system to fit your needs, works, too.