[JumpCrisscross]

> isn’t there an implicit IRR that a household would maintain and usually a 20 year payoff would be maybe not the first use of investment dollars?

Yes. Also, the risk for industry is going all in right before a new technology comes out. At that point, you either write off your original investment and deploy the new kit. Or you accept a structural energy-cost disadvantage.

I am massively pro renewables. But you have to ignore a lot to pretend it's without risk.

[scoofy]

The system already pays for itself. The only thing you lose if a new technology comes out is opportunity cost. You also likely don’t want to be an early adopter of the newest tech anyway if this is a concern for you.

This doesn’t really make sense to me as an objection, so maybe I misunderstood.

[hansvm]

There's a sort of mixing of units happening here, and I think it's causing some confusion. Here's an example (greatly simplified) scenario highlighting a flaw in your rationale:

1. Energy at your normal usage costs $1000/yr.

2. You can spend $20k now to have access to equivalent energy output for the next 40 years before it degrades to unusability.

3. Next year, somebody invents a flux capacitor bringing all energy costs for everyone down to $1/yr.

If you don't buy the thing, you spend $1039 over the next 40 years. If you buy the thing you spend $20k, and it's hit its expected lifespan, so you don't recoup any further benefits.

The real world has inflation, wars, more sane invention deltas, and all sorts of complications, but the general idea still holds. If you expect tech to improve quickly enough and are relying on long-term payoffs, it can absolutely be worth delaying your purchase.

If you predict massive improvements in solar/battery/etc tech, the only way it makes sense to invest now is if those improvements aren't massive enough, you expect sufficiently bad changes to the alternatives, etc. I.e., you're playing the odds about some particular view of how the world will progress, and your argument needs to reflect that. It's not inherently true that just because solar pays off now it will in the future.

[JumpCrisscross]

> system already pays for itself

No, it yields savings. This is a massive difference.

> You also likely don’t want to be an early adopter of the newest tech anyway if this is a concern for you

This is a real concern for any long-term investment, particularly when we're talking at utility/industrial scales. Dismissing it like this is basically arguing that solar is too new to be properly talked about, which is nonsense.

[scoofy]

I guess, though, the actual “solar” part of the solar set up is by far the cheapest part.

The vast majority of the set up costs are just getting electrification done right.

Like, even if LNG becomes crazy cheap, a battery set up will still save you money in the long run just by allowing off-peak demand.

This is why I’m confused: for this to me remotely a bad investment, basically everything possible has to go wrong for you, whereas the risks associated with carbon energy production are very obvious and very likely.

Do you have some more likely counter scenario?

[JumpCrisscross]

> even if LNG becomes crazy cheap, a battery set up will still save you money in the long run just by allowing off-peak demand

See Uruguay. Bet heavily on renewables [1]. Baked in a high cost [2].

If LNG becomes crazy cheap and you're stuck with expensive solar and battery, the countries with cheaper power will eat your industry. On a household level, you wasted money. The alternate you who didn't put money into the solar and battery set-up could have earned more from other investments and had cheaper power.

Put another way: if you remove the decommissioning costs, the same argument could be used for nuclear. Once you've built it, it's sort of "free." Except of course it's not. Building it took a lot of work.

[1] https://en.wikipedia.org/wiki/Energy_in_Uruguay#Electricity

[2] https://www.globalpetrolprices.com/Uruguay/electricity_price...

[amarant]

Per your sources it looks like they are subsidising industry use of electricity with household usage:

Household electricity prices are 157% of average in SA, and 200% of industry prices. That's not a case of renewables backfiring, it's a case of strange policy resulting in weird pricing.

[JumpCrisscross]

> they are subsidising industry use of electricity with household usage

Germany had to do the same thing when their power costs threatened de-industrialisation. The base cost of electricity in Uruguay is higher than its neighbors’ in an environmentally-wonderful but economically-problematic way.