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Comment by Qwertious | Hacker News Reader

>So it's more correct to say that local generation is 100% renewable, not total energy consumption.

The common term for this is "net 100% renewables" as opposed to "gross 100% renewables", and is typically defined as exporting more renewable electricity than you import fossil-electricity while simultaneously not generating any fossil-electricity locally.

And in Australia, whenever a state talks about "100% renewables by 20XX" they're almost always talking about net 100% and not gross, so it's a reasonable-ish thing to leave off. Still annoying, mind you.

So the headline isn't incorrect, just annoyingly ambiguous.

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That’s still deceptive. Renewables don’t cancel out fossil fuels, whether you import them or not.

Um. The exports exceed the imports. They are net exporting renewable power to Victoria. The fact that Victoria exports back non-renewable power isn't in their control.

Tasmania is an exceptionally small state. Population 500K. Based on the renewable power sources available, they must rely on a network for stability. Otherwise, they would have to massively over-develop their power infrastructure. This itself would be unsustainable.

The issue is not that Tasmania needs to over-build. It's that Victoria needs more renewables. If TAS was a net importer, that would be a different story.

> The fact that Victoria exports back non-renewable power isn't in their control.

So it is not in their control to be powered only by non-renewable energy. The rest of what you have written doesn’t change this simple fact.

They could use energy storage just fine. However, by on net exporting electricity they reduce the amount of fossil fuels Victoria uses so it’s a net win environmentally.

Nuclear has similar issues where baseload generation is inefficient when trying to cover shifting power demand. Thus small cities next to nuclear will import power even if they are a net exporter. In the end larger electricity grids are simply more efficient.

What does any of this have to do with the fact that the title is incorrect?

The title is correct. They are also using another area as an efficient battery which is both environmentally and economically a net positive.

Show me how all these numbers add up to 100%.

Production always exceeds consumption due to transmission losses.

So, simplified you can produce 120% export 15% and import 5%. That’s net export, and covering 100% of demand. That’s also how they can have a “200 per cent renewable target by 2040.”

If I open Wikipedia what I see is "100% renewable energy refers to an energy system where all energy use is sourced from renewable energy sources." which is completely what I would expect from the definition of "100% renewable energy." What you are talking about seems like meaningless political wordplay.

Plenty of ways to define things.

Batteries for example aren’t actually renewable energy sources. So when a solar or wind powered off grid home uses batteries to store solar energy for later usage is that 100% renewable energy as long as the power is originally from sunlight?

It seems somewhat silly to say such homes are battery powered. The same terminology is used when homes skip the batteries and send power to the electric grid only to use that amount of power later. Sure, they could spend more resources building batteries, but that’s wasteful.

Don’t get me wrong, it’s easy to disagree with the common definitions. However, as long as the definitions used are common and describe the situation you can’t say they are lying.

PS: Fossil fuels are also from sunlight just like wind, so saying their not renewable is really talking about the ability to use them vastly faster than their created. Which fits the batteries / grid as renewable energy storage definition just fine.

> Plenty of ways to define things.

Yeah, so why choose deceptive ways to define things?

> Batteries for example aren’t actually renewable energy sources.

They aren’t a source at all. They are just a way to store energy.

> So when a solar or wind powered off grid home uses batteries to store solar energy for later usage is that 100% renewable energy as long as the power is originally from sunlight?

Sure, why not?

> Don’t get me wrong, it’s easy to disagree with the common definitions. However, as long as the definitions used are common and describe the situation you can’t say they are lying.

I don’t know about that. It seems quite hard to disagree with the common definition. It seems very apt. The definition you seem to defend on the other hand seems like meaningless political drivel.

> Um. The exports exceed the imports.

As per the GP's comment, in 2020 that is not the case and have been a net importer.

They kind of do though; exporting renewable power means less non-renewable power needs to be generated by the importer.

It cancels non-renewable power that was not produced, when you also subtract non-renewable energy that was produced you are doing double counting.

CO2 levels are global and the atmosphere is a pretty good "storage technology" for CO2. It doesn't matter where and when you pollute. It only matters how much you pollute.

If renewables+fossil fuels allow you to pollute less than either renewables alone or fossil fuels alone then that's what you should do.

Sure, and if Tasmania was powered 100% by renewable energy it would be less efficient.

Look at it this way: if Tasmania ceased to exist, CO2 emissions from power generation would increase, because on average Victoria would need to run their coal plants more. That strikes me as a pretty pragmatic definition of "100 percent powered by renewable".

Edit: per comments downthread, perhaps they're actually not quite there yet, but still I think the principle holds if internal generation is exclusively renewable and net imports are negative.

> if Tasmania ceased to exist, CO2 emissions from power generation would increase

So it is actually over 100%? I don’t understand what you are even calculating when you say 100%, for me it makes no sense.

The GP described Tasmania as _importing_ more energy in 2020 that it exported, so by definition it can't be "net 100% renewables".

In a longer time frame they normally export more energy, but they are just announcing that all (used) local generation capacity is renewable, so even if we look at a longer time frame they still don't meet the definition.

Assuming they get normal rainfalls next year (and nothing else interrupts local generation) then they will likely hit the "net 100% renewables" target next year.

I believe the GP's complaint is that they're announcing something -- the ability in normal conditions to generate all their electricity through renewable means -- in a way that could easily be parsed incorrectly to mean they are doing so currently.

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