Scheduling My Electricity Usage

This is what ends up driving me nuts about IoT - these should be the kinds of low-hanging fruit that are already solved.

Dishwasher, laundry, etc, should be able to ask the house when the most sensible time to run this load is. For grid-tied that could be off-peak, or even better, an API from your energy supplier. For off-grid, this could be during surplus generation once the batteries are already charged, etc.

Or perhaps we're midwinter and it makes more sense to run one today and the other tomorrow.

Instead they're more worried about making sure my dishwasher can re-order Genuine Partner-Brand Tablets, so I never have to worry about running out of Genuine Partner-Brand Tablets. Reducing my energy usage only seems to matter when it's legislated, but that kickback from Partner-Brand pays off every day.

I set my heat pump to only work between 9:30 and 16:00(since I got floor heating it keeps house warm over night and concrete works as storage). I set 200L boiler(inside heatpump) to heat water between 12:00 and 14:00 and we never run out of hot water. I charge car either between 12:00 and 15:00 or between 01:00 and 05:00, depending being sunny day. Dishwasher is on timer to run at 01:00. Washer runs around 12:00. All this is doable when working from home.

Hardest part avoding peaks is cooking diner… But even then induction is pretty efficent.

Meanwhile I did a fire course and the firefighter running it said "never leave applicances on over night or unattended" (rule 2 after "always close doors").

Not that I always do not do so (the dishwasher and washing machine in particular), but the coming millions of cars drawing double digit kilowatts at night out of domestic electrical systems is probably going to cause a few fires.

While I don't care about the whole carbon boogeyman spectacle I do care about minimising our environmental impact as well as dependency on, well, as many external things as I can. One of those things is electrical power so I put about 14.5 kW worth of solar panels on a barn roof, connected to a 10kW hybrid inverter [2]. Since I don't like external dependencies I do not use the supplier's "cloud-based" management feature - Fronius Solar Web for those who care about such details - and disallow the thing access to the 'net. Instead I made my own system based around OpenHAB [1], a bunch of ESP8266 microcontrollers hooked up to things like the utility power meter (which has a handy P1/HAN port just for that purpose), a heat pump, a water heater, a small heater in the feed storage etc. The thing gets hourly electricity prices for today and tomorrow and creates a schedule to enable/disable devices based on demand, price and energy production from the inverter. Once I had everything set up it has worked fine without the need for intervention. This does not yet include the washing machine and dishwasher since these devices do not offer an easily automatised interface and because scheduling their use also depends on what we put in them and when we want them to clean those things. I just check the graphs to decide when to switch them on which works fine, no need for more automation.

Our electricity rates - both use as well as returns for power we deliver to the net - vary by the hour. Using the interface to the utility meter and the inverter I get readings every 10 seconds, the inverter also tells me the net frequency so it is easy to see whether the net is overloaded (frequency clearly below 50 Hz) or oversupplied (clearly above 50 Hz).

[1] ...but I have not yet connected a battery since a) we can sell overproduction and b) batteries are still too expensive. I expect battery prices to go down once enough used electric car batteries enter the market.

[2] https://www.openhab.org/

More utilities are rolling out time of use rates to encourage consumers to use electricity during off peak hours.

Even if you don’t have a direct financial incentive, it’s better for the environment to shift your usage to off peak times. The duck curve comes to mind.

Since heating/cooling is the largest share of usage, I try to run a schedule with good setbacks and pre-heat/cool during before peak hours. I try to do laundry during the day and run the dishwasher at night after peak hours — morning would probably be better but our dog hates it.