Several years back I was thinking about the ideal shape of solar panels, and concluded that the best is the geodesic dome shaped structure. This shape will have the optimum sunlight exposure regardless of the location of the sun during the day.
Things get interesting when you start minimizing the total system cost of the solar panels + batteries. Household power usage peaks at dusk and dawn.
In on extreme, you can either aim panels for optimal daily production (minimizing panel count) and buy more batteries, or aim extra panels at the horizon so that you don't have to store as much electricity for peak times (minimizing battery count).
In practice, something in between the two extremes probably makes the most sense, though most installers err toward minimizing panel count these days.
It's interesting to note how optimizing in this way achieves its gains by trading away flexibility, and possibly becoming self-reinforcing.
"Household power usage peaks at dusk and dawn" is true for households on average, during average (normal) conditions. If your energy production is optimized for the average case, you'll face problems when your household schedule changes. Say you take a week of leave to do some home improvements, or everyone in your house is down with a flu, etc. - suddenly, your power usage might become flat, or have more and bigger peaks during the day. It's not a big deal if you're just selling to the grid, but if you're relying on your own solar power, it's now something to plan around - you lose lifestyle flexibility.
At larger scale, if everyone has their solar installation built based on this "working household" assumption the transition from fossil fuels towards renewables turns the "two peaks" phenomenon from something that sort of happened on its own, into something people are being forced to follow, because of energy availability. Optimizing solar panels for morning and evening load suddenly stops following a preexisting pattern, and becomes the cause of it.
For both of those reasons, it's best to overprovision panels or batteries (or both), or, where possible, install the kind that follows the Sun.
