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Comment by mulmboy | Hacker News Reader

Peak solar production during the middlish periods of the day in summer. Peak demand (if your grid is summer peaking - some peak in winter) is likely in the afternoon when people get home, right as solar output starts to taper off. It all varies a bit by culture and climate, but I think this is largely true.

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This pattern may have changed or be different in different states, but I did participate in a project (about 15 years ago) where we essentially agreed to offline a very significant facility including a datacenter at short notice in exchange for a rebate and capital funds.

In our case I definitely recall most of those outages happening midday as it screwed up lunch. There were other factors as well (I think transmission efficiency diminishes as you approach capacity, so localized issues are a thing)

You can easily offset that changing the angle the panels are installed at. People think in terms of maximum total output but tracking solar show significant power is available late in the day.

As solar keeps getting cheaper the question shifts further from how do I get maximum power to how do I maximize my investment. Which is a slightly different and far more complex optimization problem.

Yeah you're right. But, tracking solar (and solar with fixed positioning that maximises energy output later in the day) largely applies for more sophisticated sites such as commercial and industrial. I've seen such setups that forego around 20% of solar energy production to maximise production during more expensive time of use windows (including offsetting time of use demand charges).

Residential installations are usually setup to maximise the total output, and often the positioning is constrained by the geometry of the roof. Residential solar installers are really in a race to the bottom.

One up and coming trend which might have a significant impact on this is for residential retail tariffs to be directly linked, at 30min resolution, to the wholesale energy market prices.

> One up and coming trend which might have a significant impact on this is for residential retail tariffs to be directly linked, at 30min resolution, to the wholesale energy market prices.

From what happened in Texas recently that sounds like a nightmare for consumers. https://www.npr.org/2021/03/06/974417969/texas-wont-reduce-1...

yeah - you shift the risk from the retailer onto the consumer. Usually these deals will have some kind of faux-insurance arrangement baked in where the consumer will never have to pay more than something like $300/MWh

I just signed up for amberelectric.com.au. They offer the wholesale power rate (set every 30m by the electricity market authority) and the wholesale solar power feed rate, for a $15/month flat fee.

They avoid the Texas problem by limiting the maximum rate to be no more than the government regulated "default power offer" over the entire year.

Planning on getting both solar power and a battery system in the next 12 months, changing my electric hot water to a heat pump and moving to hydronic heating and split system airconditioning.

I'm also going to install a second circuit back to my smart meter that will connect to my apartment garage space so that an EV charger can be installed in the future.

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