Now is the winter of our discontent
Made glorious summer by this sun of York;
And all the clouds that lour’d upon our house
In the deep bosom of the ocean buried.
– Gloucester, Richard III (William Shakespeare)
OK so perhaps I’m using that a bit out of context; where Glouceser is speaking on a time of unhappiness past, I’m in the middle of winter, and I’m fairly discontent!
Mainly because it is one of the coldest winters in Sydney for about 20 years so far, with some record days in terms of low temperatures. I’m not even going to type that much because a warm bed is calling me.
— Nick Pfitzner (@NickPfitzner) June 25, 2016
Frost isn’t unusual for Sydney, of course, particularly in the western suburbs. But it has hit a little earlier than I remember, and daytime temperatures are staying in the mid-teens, or around 60oF.
This is Australia for goodness’ sake! We don’t DO cold.
That attitude is reflected in our lack of double glazing for standard housing. If I had the money, I’d give it some serious thought.
What it has meant for the UTP household is an increase in imported power as we run that (cursed) ducted air conditioner for heat.
Here are some of the dials, edited to exclude GridCredits/Battery, from Reposit Grid Portal, Wednesday 29 June.
This is the general pattern on a bright winter’s day – we get up and consume a whack of energy in the morning, with the ducted heating adding to the breakfast needs. The green spikes on the top right are around 5kW consumption, mostly import.
The Powerwall is typically exhausted by morning in this weather, due to evening heating requirements. This is utterly necessary to prevent widespread misery, wailing, and gnashing of teeth.
I’m not even complaining about the heater usage because brass monkeys are getting distinctly uncomfortable. Its that cold.
Get the ice scraper, Edgar… and the thermals…
You can see from the Reposit data screenshot that the solar generation is still kicking a fair amount of butt on the bright days, with the light hitting the panels from around 0730 hours through to around 1630 hours here. It’ll get up to around 3.8kW in the middle of the day.
That is a fairly good amount of power considering we’re in the shorter daylight period of the year. A week earlier, right around the equinox, I did 21.5kWh which is pretty schmick. Either side of that, it was closer to 12.5kWh as intermittent cloud interrupted my flow.
I’m even exporting a few kWh because the battery is still filling up before midday. On cloudy days, I’ll turn the pool equipment off to save about 1.5kWh of electricity as well. So while its not all gravy, its still cheaper than having no solar/Powerwall at all!
Its just addressing those morning and evening heater requirements that is the issue, and even with the thermostat set to 19oC, there is a fair bit of juice needed to kick the old girl off.
I’m getting a meter changeover done so that I can move to time-of-use. This will take full advantage of Reposit’s ability to charge the battery off-peak and deploy that power when I need to head off peak running.
Speaking of which – first bill due in the next week, so expect excitement!