Hacker News Reader

Comment by mrits | Hacker News Reader

It's not always a no-brainer. If you live in a good established neighborhood in a warmer climate you'd have to remove tree coverage. Even if you did that, it's the other guys not oil or gas that will make it a hassle.

View on HN

New panels are much less impacted by shade. Friends out of town just installed the same setup as ours, didn’t want to cut down three monster Doug firs shading their roof in summer.

Made 6.9Mwh in 2025, only just less than ours with no shade at all.

I mean physics would dictate that shade impacts performance but if you are able to break the laws of physics I am impressed!

And bifacial panels with higher efficiency were invented to work around that physics.

Real numbers don’t lie.

No one works around physics. You work with physics or you don't work.

What you are describing is adding more solar capability to counter act the shade. Also the other part of it is that the panels work in parallel/not in series or alternatively don't dis activate as many conversion points as possible.

Physics never lies - they are the only laws that you cannot break.

Shade on older solar systems would impact energy production disproportionally. You would typically see dramatic reductions like 50%-80% reduced output due to 10-20% shade. New shade-tolerant solar systems are closer to being proportional.

This is because a string of panels in series are limited by the weakest link — if one cell is fully shaded, it blocks electricity flow through it, and therefore through the whole string. Bypass diodes mitigate that to some extent. But with electronics costs still falling, it's now possible to use more smaller inverters to connect the solar array to the grid, each one with its own separate string, or even an individual panel (which is a series string of cells).

Houses where the roof is completely in the shade from trees? That's not a very common sight.

Depends on the city. Here in Atlanta we are a "city in a forest" and for older neighborhoods with mature trees it's more common than not.

It's a very common site and greatly increases the value of the property.

It reminds me of when I was telling my Canadian friend how my pool gets a lot of leaves in it from all the trees and they said that was unfortunate. In Austin the pools get too hot to actually swim in if they aren't shaded.

Reply on news.ycombinator.com