[Retric]

> 2 weeks of clouds or 2 weeks of no wind

AND not OR. To actually need 2 weeks of storage you would need both 0 output in solar for 2 weeks and 0 wind for two weeks and 0 output from hydro. That doesn’t happen.

You still get solar power on cloudy days, it just takes more panels to generate some specific level of power.

The goal is to minimize X$ for generation + Y$ for storage while guaranteeing sufficient supply. Any study approaching things from any other set of assumptions is going to give you nonsensical answers.

[tonyarkles]

So I'm living up north here where from Nov 15 to Jan 26 we get less than 9 hours of daylight per day and the sun is at a low angle above the horizon. We won't be generating anywhere near nameplate capacity even if the sky is clear due to the ubiquity. Add clouds and the short day... and it's really rough for a few months. Sometimes it's windy when it's dark and cold, and sometimes it just stays cloudy and calm for a while. To make it through the winter here you're going to need to either build out massive amounts of storage or dramatically over-provision the wind and solar and deal with curtailing it in the summer.

[kelnos]

This is why advances in even-longer transmission lines will be necessary. Even if you your power is generated 3000km south of you and needs to be shipped up, the transmission line losses will only be, what, around 10% or so? That might mean your electricity is a little more expensive than it is for people who live farther south, but it's probably still cheaper than what we have now.

[7thaccount]

The idea of an HVDC macrogrid is possible, but will be hard to believe expensive and would be a huge vulnerability.

[Retric]

Sending a meaningful chunk of US electricity through HVDC lines is probably not that expensive.

A hypothetical estimate of 100% NYC’s electricity from Southern Arizona to NYC across HVDC adds up to ~1,300$/per person for infrastructure that lasts ~50 years.

East/west is even cheaper because people on both ends would want to move electricity. Florida solar kicks in early in the morning for California and California solar is still available late into the evening Florida time. You have some losses across HVDC, but you have losses and battery degradation with storage.

[7thaccount]

The cost to build a loop of transmission across the entire US is EXTREMELY expensive. It costs billions just for short segments of transmission.

[Retric]

The only reason to build them is because they lower your total costs. Over its lifespan the value of power lost in transmission over a 1,000km HVDC line in regular operation is significantly more than the direct costs to build and operate one. But you can get a lot more efficiency building solar in Nevada vs the northeastern US which more than pays for those costs.

So, if by short distances you’re talking 1,000+km and 10GW then sure it’s billions. However, the US is only so big and Billion’s don’t actually mean much to move over 2% of the US’s total electricity.

[rgmerk]

Corollary: energy is going to much more expensive the further you get away from the equator (in the absence of very predictable winds/lots of hydro/cheap geothermal).

[tonyarkles]

Yup… we’re probably building nuke plants. We are also building wind and solar. And some new natural gas plants. We don’t really have a whole lot left to tap for hydro, don’t really have good geography for pumped hydro storage, and while there is a pilot project on the go to try to generate electricity from mediocre geothermal we definitely don’t have good geothermal potential either. But… we sure grow a lot of food! And are starting to look at shuttering the coal plants.

[pfdietz]

No, we'll build lots of wind, and also smooth long term imbalances with hydrogen.

Heavy industry will tend to migrate to sunnier areas.

[hnaccount_rng]

That is the opposite of what we are seeing though. Which largely comes down to "hydro works really well with melting snow" and some level of "it's windy up here". But for solar, you probably have a point

[medoc]

> You still get solar power on cloudy days, it just takes more panels to generate some specific level of power. That is wrong. On cloudy winter days the inverters often just stop. Source: have 20kW of panels on a house in the south of France.

[Retric]

That’s a technical problem on your end. I still get electricity on cloudy days when the panels are covered in inches of snow.

Now my personal power output does tank during this period, but such extremes are local events. Further hydro, nuclear, and geothermal just don’t care about clouds.

[beAbU]

Theres something wrong with your setup. I get about 10-15w of production in the dead of night with a full moon. Source: 5.5kW of panels on a house in South Africa.