Thread: Future of the Australian Electricity Market

Originally Posted by woodPixel

Induction is incredible. I read a recent article on the BBC that all the top chefs have (essentially) switched to induction.

It's damn good alright. I only have a single portable hotplate that I bought to make sure I like it (and I do). This one always delivers full power (2000w) so when I turn it down to 200w it is only on 10% of the time. That's only "kinda" ok. I'm sure that is better controlled with the more expensive "proper" built in units.

However, there is one thing that you can't do with induction (or any other electric cooker), that you can only do with gas – hold the pan above the heat for flipping a stir-fry over and over, which I do ALL the time. A "flip-fry" is far more efficient than a stir-fry for moving the ingredients around. Firstly, with induction, the pan is no longer getting any heat, and secondly the hotplate starts beeping like the house is going to burn down...

We have 3-phase power to the house, 6.6kW of panels on the roof connected to a 3-phase 5kW Fronius inverter. The system routinely kicks out 5kW on a clear sunny day. Output from the inverter is spread across 3 phases, so I needed 3 current sensors when I put in Zappi V2 EV charger. The Zappi needs to know TOTAL solar power being generated across all phases, then it only charges the car at that rate so nothing is drawn from the grid. If the sun goes behind a cloud the Zappi suspends charging automatically until there is enough excess solar to charge again.

No problem adding more panels to the roof, BUT you can't "upgrade" an inverter. That would mean throwing out/selling the existing one and buying a new one of larger capacity. So, if you want to expand solar you may as well add more panels and a new inverter as a separate system (e.g. on my workshop roof). I thought (in NSW) you could have at least 5kW solar per phase, but I'm not sure what the rules are now. I wish I had put on 11-12kW of panels feeding a 10kW 3-phase inverter.

We always thought "gas cooktop is best", so put that in when designing the kitchen. All this "gas bad, electricity good" Animal Farm (Orwell) stuff only happened in the last couple of years I think. I'd need to find an induction unit which would be a drop-in replaceemnt for the gas cooktop in a stone benchtop

Originally Posted by Mr Brush

All this "gas bad, electricity good" Animal Farm (Orwell) stuff only happened in the last couple of years I think. I'd need to find an induction unit which would be a drop-in replaceemnt for the gas cooktop in a stone benchtop

For me it's not so much gas being a fossil fuel, because the amount consumed for a cooktop is tiny (also remembering net zero targets). It's having the connection fee of 70c per day, or the bottle storage and refill costs.

Very true. For us, a 45kg cylinder lasts about 5 years (we had gas cooktop in the old house too). At one stage I was starting to think I had acquired a Magic Everlasting Gas Cylinder.

Originally Posted by FenceFurniture

A Tesla Powerwall 2 is $14,000 installed, and they are 13.5kWh or 13,500Wh, so about 1$ per Wh.

Mr B's Atto 3 has a 60kWh battery and the whole bloody car only costs $48,000+ (and the + doesn't affect the battery size).

Let's say it costs $20,000 to replace the battery in the car. That's about 33c per Wh to purchase a battery that goes into a difficult shape of a vehicle, not a nice neat rectangular box.

There is rarely a consistent correlation between the cost to produce an item or a service and the cost to the consumer of that item or service. The cost to the consumer is based on what people are prepared to pay. The key is to find a business where you have a low production cost for an item that people will pay a lot more for than the cost of production.

A good example of this is compare the cost of photocopying a document for 10 cents a page. The business scans your document to a digital file then prints out that file through an expensive printer onto sheets of paper which they provide, using lots of resources. Compare this to taking the same document and scanning it to a PDF for 40 cents a page. They still scan your document to a digital file, then save that file onto a USB stick which you provide. They charge you four times as much and use less resources and the only materials you get back, you paid for and supply as a separate transaction.

Why can they get away with this? Because people want PDF copies of documents so that they can email them so they are prepared to pay more for less service because it is convenient. Prices are not dependent on what the item costs to produce. It's all about how much people are prepared to pay for them.

Originally Posted by FenceFurniture

Ok, so I have a question about batteries:
A Tesla Powerwall 2 is $14,000 installed, and they are 13.5kWh or 13,500Wh ...

Elon's marketeers say the capacity is 13,500 Wh, but when you look at the warrantee his lawyers say that it is 13,100 Wh.

This is a first for me; I think I believe the lawyers.

Work out how much electricity you can realistically put into the battery over its expected lifespan, without rosy glasses, then divide that into the capital cost. Bloody expensive storage fee. Add the interest foregone, and it is much cheaper to buy from the grid!

Originally Posted by woodPixel

... I can rapidly see a day where my dinosaur will be taxed out of existence.

Interesting hypothesis, Evan. The governments now collectes a lot of tax on fuel, car import duty and rego, but only spend less than half of that on roads. With the pervasive ethos of not taxing green electric vehicles, this is going to put a big hole in their revenue.

Prepare for an inovative new tax!

Originally Posted by GraemeCook

Work out how much electricity you can realistically put into the battery over its expected lifespan, without rosy glasses, then divide that into the capital cost. Bloody expensive storage fee. Add the interest foregone, and it is much cheaper to buy from the grid!

All the more reason not to buy a house battery now. In reality, it's never been a good idea because of the time to recover costs, but even as house batteries become more viable (price) using your car battery has to be the only way to go – why buy two batteries when you only need one, and that is many times bigger...and cheaper? In the not too distant future you won't have any choice but to buy an EV if you are looking for a brand new purchase. I can see house batteries coming to a grinding halt quicksmart, except for the people who don't drive.

Not very much comes for nothing.

If we use the car battery to power our household, that power had to come from somewhere. That somewhere is either a sufficiently large solar array at your home or the grid ( could be any form of power for the moment although one day it could be 100% renewable.) If you use the car battery to power your home, you don't have that amount of consumed power to run your vehicle and you will have to recharge it somewhere. If your solar array is large enough, you may be able to achieve this, providing you did not have to leave for work (or pleasure) before the sun came up.

What is possible is, if and when peak and shoulder pricing comes into effect, whereby you can charge your batteries and/or car during low prices from the grid and use that stored energy at night when prices are high. We are already seeing this on the grid for the wholesale market and it is the complete opposite of the pricing regime, say, one year ago.

While an EV battery might well be a good back up for night time supply it seems to me that it too comes at a price.

No such thing as a free lunch.

Regards
Paul

Even the smaller EV batteries are (relatively) huge capacity compared to Tesla Powerwall. Our house uses about 9kW/day (including heating hot water in heat pump system) - with very little inconvenience or hardship, I could easily get that down to 6-7kW total/day.

Assuming zero sun and no opportunity to recharge from solar, the 60kWh in the EV is still sufficient for several days' use without impacting too much on the range of the EV. During the recent floods and power cuts in NZ, several Atto 3 owners happily ran their whole house from their car battery for a whole week, and still had sufficient juice left in the car to drive it. These days 60kWh isn't that large for an EV, several already have 70-75kWh batteries. It's a completely different proposition to a Tesla Powerwall.

Paul, I think the general idea with car batteries powering homes is that the house might need (say) 5-8kWh overnight – mostly in the evening – and that is coming out of a battery with a capacity of (say) 60kWh, so it's only consuming 8-13% of the car charge.

The whole scenario will be different for every different consumer: how many days do you work from home (when you can charge your car during the day), how far is it too work, how much power do you consume in the evening, how big is your solar array, can you charge your car at work from green power, and no doubt a few other things thrown in there. Someone mentioned a moveable feast earlier. This has a long way to play out yet, but I do feel somewhat excited to be living through this transition.

In 20 years people will say "What was all the fuss about? The solution was easy." The solution is always easy in hindsight, but it has to be deduced and arrived at first, otherwise we'd have skipped the whole horse and cart thing, skipped ICE vehicles, skipped EVs, and we'd be transporting around in....well, what, exactly?

Who knows what is coming soon? With battery tech being a "gold rush" we may very easily find ourselves with batteries that have a module that is easy enough to pull out of the car and drop into the house to run it, while we toddle off to the shops for some Thursday night shopping, or go to work.

I betcha it ends up like battery tools – you have a whole bunch of tools, a smaller bunch of batteries, and just swap them around as needed. More or less

Snap....lol

Originally Posted by Mr Brush

These days 60kWh isn't that large for an EV, several already have 70-75kWh batteries. It's a completely different proposition to a Tesla Powerwall.

Yep, and what's the bet that the vehicle manufacturers start making the whole system modular? Bigger battery capacity for same size, "plug your car into your house, etc etc". It's a whole new marketing opportunity.

When I look at the changes/improvements in battery technology over even the last 3-4 years, the rate of change and innovation is staggering. Sodium ion batteries just starting to appear, and a whole bunch of chemistries that we can barely imagine are already being trialled. Cheaper, higher capacity, smaller, lighter, faster charging, you name it.

In even another 2-3 years the large capacity EV battery market will be unrecognisable. In fact, I know that in probably 2 years the BYD Blade battery in my EV will be considered old tech. Large lumbering infrastructure like power grids, involving huge investments and long payback times, don't handle rapid technological change very well !