Hybrid systems

[slowbutsure]

Hi,

Yesterday I did a training course for Hybrid inverters. I was surprised and taken back by the idea of Smart loads. Where if the grid is working then everything is powered (combination of grid, imverter and battery) but if the grid goes down only certain loads are powered from the battery. This requires some rewriting and looks complicated.

Anyone done this or have any thoughts on it? Thanks.

 

[MaikaiLifeDIY]

I've not personally done it, but you essentially map out what each circuit runs and when you enter an off-grid situation, which circuits a opened and which ones are closed. There might even be more sophisticated ones where they monitor the current flow and open the circuit if it exceeds a threshold.

It's also possible to accomplish this without smart loads because nearly every hybrid inverter with communication ability can signal when the grid is up or down. This communication can be captured and acted on with various home automation to do many things. For example, if the grid goes down you could automate raising your thermostat temperature in the summer months, or maybe just turning the AC off altogether for some period of time. You could also make it more complicated and say only raise the temperature if the batteries get below X % SOC rather than just arbitrarily take action simply because the grid is down.

Many devices today have embedded firmware and software that once power is lost require some level of user input to reconfigure them or they need to be shut down from within their interfaces and not have the power simply disconnected. I'd rather put everything (if possible) on standby and not have to reset a clock or input settings or reconnect stuff to WIFI/Bluetooth/Zwave etc, all at once when power is restored.

Smart loads are a neat way to sell more gear and equipment that is probably really reliable and in certain situations makes a lot of sense, but In my home, I'll handle the intelligence of maintaining critical loads myself with automation that lets me do more than pull the plug.

 

[slowbutsure]

I've not personally done it, but you essentially map out what each circuit runs and when you enter an off-grid situation, which circuits a opened and which ones are closed. There might even be more sophisticated ones where they monitor the current flow and open the circuit if it exceeds a threshold.

It's also possible to accomplish this without smart loads because nearly every hybrid inverter with communication ability can signal when the grid is up or down. This communication can be captured and acted on with various home automation to do many things. For example, if the grid goes down you could automate raising your thermostat temperature in the summer months, or maybe just turning the AC off altogether for some period of time. You could also make it more complicated and say only raise the temperature if the batteries get below X % SOC rather than just arbitrarily take action simply because the grid is down.

Many devices today have embedded firmware and software that once power is lost require some level of user input to reconfigure them or they need to be shut down from within their interfaces and not have the power simply disconnected. I'd rather put everything (if possible) on standby and not have to reset a clock or input settings or reconnect stuff to WIFI/Bluetooth/Zwave etc, all at once when power is restored.

Smart loads are a neat way to sell more gear and equipment that is probably really reliable and in certain situations makes a lot of sense, but In my home, I'll handle the intelligence of maintaining critical loads myself with automation that lets me do more than pull the plug.

Thanks. The reason they use smart loads here is for the company selling the system to protect the battery so that after it’s installed the user doesn’t add an two AC units and shorten the life of the battery when there is a brown out. Do you think that’s valid? Is there a simpler way to protect the battery? Thanks.

 

[DIYrich]

Smart load can also be a poor man's load control. Put heavy loads on the smart load. When grid goes down, smart load disconnects, and large loads turn off. When you want to run a large load on battery, you turn off the other large loads, energize the smart load, and turn on the device you want.

 

[slowbutsure]

Smart load can also be a poor man's load control. Put heavy loads on the smart load. When grid goes down, smart load disconnects, and large loads turn off. When you want to run a large load on battery, you turn off the other large loads, energize the smart load, and turn on the device you want.

Instead of smart loads to protect the battery I was thinking of just putting a smaller breaker on the ac output of the system. And maybe decreasing the depth of discharge.

 

[robby]

There are a couple of smart loads panels on the market. I have been eyeing the always to be released next quarter Sol-Ark panel.
My understanding is that it intelligently tracks and stored data on the appliances consumption taking factors like temperature and the time of year and builds a predictive profile on its consumption that is used if utility goes down.
It factors in your personal preferences and keeps what you must have running powered on but luxury items that are free on your secondary list may come on at the times when you need them if the SOC is high enough to allows it.

 

[Steve777]

Smart load panels can certainly help manage the loads in a grid down or low power situation. However several of the new inverters have multiple load outputs which can be controlled. So you can have a general load panel which will get turned off when power is below a set level, and a critical load panel which will continue receiving power for longer, and possibly more. A couple of new inverters which have this feature I've seen are the new Watt247/Amen solar and the upcoming Midnite AIO.

I believe it was Robin of Midnite who said that smart load panels were an expensive way to accomplish load shedding, which is why Midnite had built that into their new inverter. I expect this feature will be included in more and more inverters in the future. I just makes sense to do and is not that costly a feature to add to the inverter.

 

[MaikaiLifeDIY]

Thanks. The reason they use smart loads here is for the company selling the system to protect the battery so that after it’s installed the user doesn’t add an two AC units and shorten the life of the battery when there is a brown out. Do you think that’s valid? Is there a simpler way to protect the battery? Thanks.

If you've got LifePo4 batteries and you have your inverter monitoring the SOC on the battery bank with shutdown thresholds enabled, you don't need smart loads to protect a battery. Smart loads aren't about battery protection, they're about reducing non-essential loads during offline usage.

 

[slowbutsure]

If you've got LifePo4 batteries and you have your inverter monitoring the SOC on the battery bank with shutdown thresholds enabled, you don't need smart loads to protect a battery. Smart loads aren't about battery protection, they're about reducing non-essential loads during offline usage.

That was my thought. It didn’t make sense to me when they said it. Thanks for the confirmation.