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The change certainly brings in some weirdness too.

For instance, I'm looking at a new hot water system. Economically speaking, I'm better off buying an oversized tank using resistive heating that I only need to heat once per day. The grid provides free power and I buy a cheaper appliance. But environmentally it sucks, as more solar needs to be rolled out to cover the additional non-peak usage (guess about 6x the power usage of a smaller tank with heatpump).

by pornel24 minutes ago|

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I get that it makes less efficient resistive heating more economical, but the tank size seems like a red herring. If you go for a heat pump you can have a larger tank anyway, and heat it during the solar peak too. A larger tank will allow you to store water at a lower temperature (instead of hotter water to be diluted). Smaller delta makes heat pump more efficient and heat loss slower.

by penteract10 hours ago|

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To check I understand you: the smaller tank with heatpump would consume less energy outside the time window in which energy is free than the large tank with resistive heating, but has a higher capital cost which would outweigh the amount saved on energy?

If that's right, it's not obvious to me that building a suitably sized solar panel is environmentally worse than building a heat pump.

by stubish9 hours ago|

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The smaller tank with heatpump will consume a lot less energy than the larger tank with resistive heat.

Economically to me, the larger tank is cheaper, because the appliance is cheaper, and I never pay for the power it uses.

Environmentally, yes, it is not obvious. The large tank requires many more solar panels to power it but no battery. The small tank and heatpump needs much less solar but battery for nighttime use.

But it is weird, because for decades heat pump tech has been pushed as the environmental choice and there are still a number of government subsidies to invest in heat pump hot water systems. And maybe that no longer makes sense, with the money saved buying cheaper and less efficient devices spent on more solar deployments.

by hnaccount_rng8 hours ago|

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But it’s also environmentally better for you to take the resistive heating thing. As long as you never need to heat it up outside of the noon-window that’s strictly positive. Because the “additional” solar panels will be necessary anyways to cover the night/late evening usage. The optimal buildout will always have superfluous energy at noon. That’s fine. We just need to get over the whole “energy costs anything” thing. That’s only true if you need to spend fuel to generate it

by Panzer046 hours ago|

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The magic of market pricing means people will figure out the best solution and optimise towards that.

Hot water heater tanks are easily one of the most obviously good applications of noon excess energy, and resistive heating elements might as well be free.

by Havoc12 hours ago|

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Surprised they’re putting everyone on same timeslot. Would have expected some staggering to be helpful

by defrost12 hours ago|

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From elsewhere:

   this applies to NSW, South Australia and part of Queensland.

so NSW and South Australia will be staggered in real time as they are in different time zones.

As for everybody in the same time zone .. they are all seeing the same sun angle at noon (more or less) and all sharing the same over supply of power from all the grid connected solar power rooftops and farms. It's free surplus power during that time frame.

by Havoc11 hours ago|

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Yeah i get that they're all seeing similar but you'd still want to align this new demand with the output curve in some form of approximated pattern. Plus also prevent the sharp spike you'd get from everyone turning on their stuff at a coordinated hour. You're gonna have a bunch of stuff on timers all hit this at the same time. That makes life hard for the people balancing the grid's supply & demand.

Bit like in the UK they had issues with everyone watching popular TV shows and then turning on the kettle after in a perfectly syncronized timing across the country

by aragilar12 hours ago|

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There's too much available power then (curtailment/negative prices are fairly common now on sunny days), and not enough during the evenings, so it's an incentive for those who don't have/can't get batteries (e.g. renters) to shift their habits. It also can be spun as a cost-of-living action.

by pydry12 hours ago|

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I find it amusing that back when solar and wind were niche and expensive the coal + oil lobby would lobby for "let the free market decide what to build".

When solar + wind plunged in price they stopped saying it.

Now that the market has driven down the price of solar, wind and storage, market based mechanisms have become ideal for solving the problem of what to do with surplus electricity.