Comment by jillesvangurp | Hacker News Reader

Comment by jillesvangurp | Hacker News Reader

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The article seems to be mostly about grid scale solar. Of course an increasing amount is private or domestic solar installed on e.g. building roofs or wherever there is space.

When cost drops low enough, any surface with any exposure to sunlight is in scope for installing solar on if it can yield more energy than the cost of installing solar on it. It stops being about what is the most efficient and starts being about if the surface is good enough to provide a decent return on investment. Maximizing that ROI is complex but it boils down to getting more value out of the installation than goes in.

Solar doesn't even have to be in panel form. Some office buildings now have windows that double for solar generation. A thin transparent coating does the job. There are roof tiles that double as solar panels. Aptera makes electric cars with integrated solar panels. These are curved glass panels that are manufactured to fit the profile of the roof and hood. It's also possible to print organic solar cells directly on plastic rolls. No glass involved. Or panels. Those are less efficient but you can integrate them on all sorts of surfaces. A lot of that stuff is still emerging technology. But especially organic solar printed on plastic rolls could end up being very cheap to produce. And very light.

Domestic solar is a rapidly decreasing fraction of total solar deployments [1]. Not because it is not growing exponentially, but because grid-scale is much more exponential with no signs of that changing.

[1] https://news.ycombinator.com/item?id=42591918

“When cost drops low enough, any surface with any exposure to sunlight is in scope for installing solar on if it can yield more energy than the cost of installing solar on it.”

I don’t see the logic? As panel prices drop, installation costs start dominating overall cost of energy produced and so economic pressures will be on simpler and simpler PV installations. Laying a panel almost flat on the ground amongst thousands of others will be a cheaper process - both initially and in terms of ongoing maintenance - than anything that involves sending workers up ladders or cherrypickers attaching and wiring a panel onto the side of a building.

So grid scale will start to dominate over domestic or “novelty” (e.g. floating panels on reservoirs) and simpler and simpler approaches to installation (like removing tracking) will become attractive.

These effects are already apparent. Basically the opposite of what you’re predicting?

Installation costs dominate largely due to one-off things (getting the contractor/customer, roof access, adapting to bespoke roof layout, etc) which are disproportionately larger for smaller installation sizes. However for new construction those things are essentially free. So yes, I’d absolutely expect that solar will be added during larger rebuilds. But that is not an effective way of “deploying solar”

> I don’t see the logic?

You use the surface area you have. Most people simply don't have a lot of ground to put solar on but they might have a roof. Also, you don't just need solar panels but also the wires to where the power is needed. On the roof of the building where you are using the power is just about as close as you can get with that.

Otherwise it's a simple economic equation. If installing solar saves enough money such that you end up with a decent return on investment then making that investment is more optimal than not making that investment.

That's why most of Australia is running on rooftop solar when the sun is shining. The US is a bit behind on that mostly because the US has a lot of rules stacked in favor of grid providers. Australia used to have that and eventually the grid providers lost that battle.

Grid scale solar benefits from bifacial cells in a vertical orientation just as much as home scale solar - it dramatically improves winter production and extends the production of the spring/fall day a few hours earlier and a few hours later.

Not only does it increase overall production, currently one of our biggest challenanges is transport and distribution, and having some of that power in the of-hours instead has more benefits than power total alone.

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