It’s been a little while since I’ve posted and, for that, I apologise.
I’ve taken on an exciting role with a new Aussie website called One Step Off The Grid which features the stories of ordinary people all over the world who are…well, going off-grid. It’s a sister publication to Renew Economy which some of you might be familiar with. I’ll be sharing some of those stories on this site; if you have an off-grid or good grid-connect story, let me know.
In the meantime, I wanted to share some stats from our system through June 2015, which is of course the dead of Melbourne winter. Not as cold as some parts of the world, but still pretty chilly!
The state of charge (SOC) of our battery bank looked something like this:
You can see that we had a run of a few cloudy days where the batteries haven’t quite floated – got to 100%. However, despite the batteries (lead acid) being 3 years old, we’re still not dropping low enough for it to be an issue. (If we were, we’d organise a back up generator that would charge them up.)
While we were aware of the days when we didn’t float, we didn’t really change our energy-guzzling habits – TV was on and we still reheated our warming soup in the microwave!
So…if you’ve been wondering (like many others) how we cope through winter, this should answer a few questions for you. Of course, if there’s anything else you’d like to know, don’t hesitate to get in touch!
(I know, I know and I’m sorry. But couldn’t help the GoT reference…and neither can the other thousand journos writing about anything to do with our approaching cold months.)
I’m often asked what happens at our place during winter. The answer is simple – pretty much the same as what happens during summer.
Solar panels need light, not heat. Therefore, as long as we get some sunlight throughout the day the battery bank will float (reach 100% state of charge). I’ve often been surprised by just how efficient the panels are at harvesting power to top up the battery bank.
What does change slightly during a Melbourne winter, is I check the weather report each day. Here’s what popped up today.
Melbourne’s weather this week
While a run of those little grey cloud symbols is slightly disconcerting, with very little power being pulled in the house during the day, the chances are there’s enough light around for the battery bank to float.
But what if there’s not?
a) the battery will have a lower state of charge (SOC), usually around 95-97% until the next sunny day.
b) we could connect a back-up generator that would float the batteries – while our system is set up to connect a gennie, we haven’t done so because we’ve never been low enough to warrant the $7k purchase cost.
I think that running out of power is a concern for people thinking about going off-grid (it was for me when we started this process a few years ago). However, in two and a half years and coming into our third Melbourne winter, we’ve never been lower than 92% SOC.
As we enter this cloudy week, I’m planning to keep a record of SOC…watch this space!