How would you approach this design?

[craigcurtin]

Hey Guys,

As part of our home automation and energy consumption we are trying to make everything a little smarter and use more of our "free" solar energy.

We currently have 15KW of panels on our house and during Summer produce just under 100KW/h of solar per day. We use a number of tools to capture the data re solar performance and to then push this to Influx for storage and trending.

I am just in process of integrating the Solcast API into our system so we can get insights into how much power we are predicted to produce for upcoming days.

So we have a number of loads that we need to run on a daily basis - some we will call discretionary and others are "mandatory" - so for instance running the pool filter is not required every day but is a nice to have (we can get by with 3 days of no filter for instance with no noticeable difference in the water quality), whereas running the dishwasher everyday is required.

I am slowly building profiles of some of our loads (such as Washing machine, dishwasher and clothes dryer) to enable more fine grained control - but at the moment each of these has to be started manually - but can be interrupted - in the case of the washing machine, it will then require manual intervention to restart, whereas the clothes dryer and dishwasher will just continue on their way.

We will shortly be moving from Gas Hot water to Electric (run through the Solar) as well as moving from Gas Hydronic heating for the house to an Electric Heatpump.

So i am looking for ideas in how to implement an energy queueing and pool system to enable me to most effectively schedule our daily loads.

In my mind i have an idea of an "energy bucket" that various loads will be able to draw from based upon their "priority level" and their ability to be paused without intervention.

This energy bucket would be created overnight based on the output from the Solcast API for the next days Solar (and with maybe some looking further forward to following days) and would then either send emails to manually kick things off at certain times (such as a load of washing and then the dryer) or would automatically run certain loads (such as the Pool Cleaner, Pool Filter, Heat pump system, Reverse Cycle AC etc etc)

Anyone got any thoughts on the best way to start crafting something like this - or any magic nodes they have seen out there that might help ?

Craig

[krambriw]

Just some thoughts; If your household has "lifestyle schemas" that would match any such profile, well...
Anyway sounds like you have at least some stuff that could be automated in correlation with smart price profiles, like the pool cleaning/heating

• how will you create the "bucket"? Install Tesla batteries in the basement?
• how does the electricity price vary during 24 hours? Weekdays? Weekends?
• does your electricity provider offer a smart price API?
• is your price plan sensitive to high peak consumptions during certain hours (Peak rates)?

My neighbour installed solar panels, I think two years ago, with the target to "at no cost" charge the familys two Tesla cars. When I chatted with him the other day, I asked about how this whole thing worked out. He said, no, he was not charging the cars, instead he was selling the electricity generated and charging the cars during night, then buying electricity very cheap. So in his opinion, in overall, it was a good business (In my country you can have various agreements with your electricity provider, one type is where the price fluctuates during the day, like the spot market)

I think you will soon find that installing the electrical heatpump will be the biggest win overall. Is it an air-to-air thing or is it a more sophisticated type where you drill a deep hole in the ground? When we replaced & installed a more efficient heatpump in our house, the total electricity consumption dropped 50%, it's amazing. We do not schedulte any heating, we keep the same temperature constantly even if we are away a couple of weeks. There are calculations that says you will consume more energy if you regulate the temperature up/down. Don't know if the same would be applicable for cooling (AC systems)

[BartButenaers]

@craigcurtin

I am slowly building profiles of some of our loads (such as Washing machine, dishwasher and clothes dryer)

Hi Craig,
I had started a similar discussion some time ago. I learned a LOT from it, but I didn't manage yet to build something because I cannot find an open source hvac system that contains a profile scheduler, which also allows my wife to turn on a device immediately (and thus resulting in a reschedule of all other profiles). Seems to be an international wife related problem

[craigcurtin]

Thanks for the answers

1. Yes it does suit our lifestyle as we both work from home and run our businesses from here - so for instance at the moment based on the Solcast API for forecast power useage i will send an email at 7AM each day - something like - Dishwasher on at 9AM, a load of washing at 11AM, Pool pump coming on automatically at 11AM, Suggest the clothes dryer at 2PM etc

2. Yes our provider offers a smart API - our provider basically provides us with Spot prices - which is where this whole thing comes from - we can get charged upto $16/Kwh if something goes wrong in the wholesale market, but we can also sell Solar back to the grid at the same price - so we had a system failure in our state last week and we sold $55 of electricity back to the grid in the space of an hour.

3. Ultimately yes we intend to install batteries - probably the middle to the end of this year - and these will rely on this bucket concept as well - but with an override for the Power API and price peaks etc - so their default programming would be the minimize/remove grid usage, with the ability to over ride to tell them to dump a massive amount of power to the grid when the prices are advantageous.

In Australia we have an abundance of Solar and wind - so the ability to sell back to the grid for high prices (with a high Solar Feed In Tariff) is starting to disappear. With our current provider we only get very low Solar FITs but they do enable us to participate in the Wholesale spot market.

The Heat pump we get will only be Air to Air - we are on a large Sandstone shelf - so the ablity to lay coils or drill bores is not available.

The way we heat our house at the moment is through a large (5000l) insulated water tank - this is heated during the day via Solar coils on the roof and as required topped up during the day and in the evenings with a Gas fired boiler.

We intend to replace the gas boiler with the heatpump - and hopefully be able to run it during the day to supplement the solar coils and bring the tank to a higher temperature - and essentially "bank" some heat into the Slab and the storage tank.

Craig

[craigcurtin]

Yes i think it will need to be more than just a HVAC scheduler - my wife is an accountant - so if i tell her it will save money then she is all for it !!

Just got to get the back end logic right and then think about the front end.

Most of our appliances are dumb so can not be controlled through an app etc - so any bits that i add on that make life easier - like reminding that the Washing machine has finished for instance and then prompting if nothing done for a period - are all wins.

Craig