Year Of The Powerwall

Let’s get straight to it: 50 cents per day.

That is what I paid for electricity over the 350 days of billing I have since the Powerwall was installed, and my electricity provider changed over.

This is important to note, as the two weeks up to change of provider meant I wasn’t getting any export benefits from my solar panels. Mugged!

The saving is over the $2000 mark, but for the sake of round numbers, let’s call it $2000.

Year Of The Powerwall
OK, so not exactly this good, but pretty good…

To put in perspective what money means to my family: our recent road trip, to central and southern NSW, cost almost exactly that. Essentially, I got my little summer break for free.

Facts And Figures

According to the billing received by Diamond Energy over the 350 day period:

  • Import total was 1349.830kWh (or 3.857kWh / day)
  • Export total was 3807.403kWh (or 10.878kWh / day)

Not quite the 1:3 ratio I was looking for, but that figure is probably no longer simple to calculate, which I’ll explain below.

From the SolarEdge web portal, I have the following factoids:

  • Lifetime energy: 9.1MWh
  • CO2 emissions saved: ~3400kg
  • Equivalent trees planted: 11
  • Light bulbs powered for a day: ~26,200

That is kind of the feelgood stuff, despite the Powerwall not necessarily being “green” as people might imagine.

As with anything, there is a carbon cost associated with production. The early iterations of any battery product are going to be a little bit on the dirty side.

As one example: Lithium ore needs to be shipped from the mine to the refining facility. The refined lithium is then shipped to the cell production facility, which may or may not need shipping to the final place the Powerwall was built.

Tesla are addressing this with “vertical integration” of production, particularly for their cars, but also batteries in general. This means more processes can be done at one site, reducing shipping costs (and therefore carbon c0st) of transporting components.

Other Factors Considered

Keen observers will remember that in October I got more solar panels. That took my total system size to 6.5kW of panels. I just heard a bunch of critics trumpet “AHA!” but keep in mind, I still only have a 5kW inverter.

Therefore the maximum power I can generate is limited to 5kW, though the peak time lasts a bit longer on a sunny day.

It is hard to quantify what effect this has on the system, beyond saying “there is more solar capacity”. As the new panels are oriented WSW they’re not always going to be ruling the roost in terms of efficiency.

Its also a smaller factor than it otherwise would be, having been installed four months out of the year. Granted, they were the sunnier months.

Another consideration is my move to Time Of Use tariffs in the first week of August. This has an effect on two areas of my billing.

If I’m smart enough to “game” the tariffs, and avoid doing anything during peak time, I can save a lot. Unfortunately peak time coincides with oven and air conditioner use, so that’s not always possible.

The billing and the import numbers above will be affected by Reposit Power managing tariff arbitrage. When I import power now, it might be a result of my needs being bigger than the system output, the battery being empty, or because Reposit sees a cloudy day and wants to import some at a cheaper rate.

Putting together the new panels and move to TOU, a better time to revisit this might be October this year. That way, I’d have a true idea of what I can really save with all components working together.

The Vagaries Of Billing

Those out for a bargain will know to shop around with their electricity companies, and see how best to maximise their savings.

Whether that is through generous sign-up rebates, or big discounts for paying on time or via direct debit. It all adds up, and people without solar or batteries can benefit if they do their research.

As I pay such low amounts anyway, discounts don’t add up to much. Pay-on-time discount across the year was $20, and paying by Direct Debit discount was $17.62.

The bigger benefit was referring people on to Diamond Energy, which netted me $105 across the year. Against that, I paid $22 (inc GST) application fee with Diamond, so the benefit was more like $83.

If we add that $83 back onto the billing, it goes from 50 cents per day to 75 cents per day.

I pay about $1 a day to connect to the electricity network, so its still good. There are even a few dollars in GridCredits unaccounted for at this point.

Year Of The Powerwall

When I say “Year Of The Powerwall” I’m not speaking only to the year I’ve had. This year, 2017, marks the landing of Powerwall version 2 in Australia, and overseas.

I’ll level with you: I haven’t really spoken much about PW2 since the launch, because I’m still experiencing some angst.

Year Of The Powerwall
So hot right now…

I thought I’d done OK with my battery, then in the same year, Tesla brings out one TWICE as good.

C’mon Elon… I thought we were mates!

Overall though, this is a good thing. I think we’re about to see the domestic battery market kick off in 2017, with Tesla in front. That is quite amazing, given the prediction was market maturation in 2020. We’re three years ahead!

Talking to a few people getting quotes and installing them, right now there are very few people price-competitive per kWh.

As the manufacturers in Korea and China start their own uplift via vertical integration, prices are going to keep sliding, and competition increase.

This can only be a good thing for the consumer, for the grid, and for energy security and stability moving forward.

And any consumer who is getting a Powerwall 2: I think a zero electricity bill is well within reach.

If you factored in selling power back to the Grid out of the battery, which I think will replace solar feed-in tariffs eventually, you could even turn a small profit.

As always, user experience may vary. Its up to you to make the most out of your investment.

An Addendum

As I wrote earlier in the month, we have had some heat wave conditions here in Sydney, with outside temperatures getting into the high 40s (120oF). That was kind of insane, but it kicked off some GridCredits for me, which is also a good thing.

As we’re moving toward more extreme weather events, having a flexible and robust grid, with user storage available for emergencies, will be important.

South Australian Storms

I’ll keep this pretty short, because the South Australian Storms are consuming a lot of media attention at the moment. This article is a bit of a linkstorm, because people have said most of this more eloquently than I could.

You can pretty much sum up the situation with this tweet:

The state of South Australia here has been hit by what is being described as a 50 year storm. The damage you see in the picture above has contributed to the entire state losing power.

As this article explains, tornadoes brought down critical infrastructure, and the network was brought down as a safety measure. Note that tornadoes aren’t a very common occurrence in Australia.

South Australia is connected to the state of Victoria for power sharing, as part of the South East grid. If the interconnector stayed up, and started demanding power from Victoria, it had knock-on implications for the whole grid.

The Good

Despite the magnitude of the disaster, there are some silver linings to the South Australian storms.

It puts battery storage at the forefront of maintaining a decentralised power supply. One household had their Powerwall running the house until power came back, thanks to Natural Solar.

Reposit Power also had a customer request for power, in preparation for the storm. Why not use the grid import facility of Reposit to grab power before the storm hits? That way, even threats to infrastructure won’t hurt the average household.

While most people can see themselves getting a battery in blackout hotspots, most would never have considered the magnitude of such an event.

Though, in fairness, I suppose most people haven’t seen a storm this big.

The Bad

Of course, it didn’t take some peanuts long to have a crack at the high percentage of renewable energy in South Australia. The state closed its last coal-fired power station a few weeks ago. It has been a nonstop bunfight since.

Renew Economy covered the primary points of attack relating to the South Australian storms. The coal lobby is really bricking it over renewables, and that’s no shock as more coal power stations are going to close.

It is surprising that someone would try to pin this on renewable energy. Particularly as the energy mix played zero part in the problem.

Another good read was from Ketan Joshi, who ran through the speed of truth versus the speed of emotion. Misinformation gets a Tesla Model S, it would appear, while Science gets a bicycle…

The banner image for both articles was this unmitigated rubbish:

The Ugly

It really boils my piss to see this kind of thing go down. You’d think no-one in recorded history had ever had a blackout before. Or that, in some wild universe, humanity has never seen a storm of this scale until solar panels were invented.

Correlation does not imply causation. Maybe some of these idiots should learn something about that.

We’ve got a state suffering the effects of one of the biggest storms in living memory, and people are playing politics, as South Australian Premier Jay Weatherill states so well.

Stay safe, South Australians. Hope you’re back on your feet soon.