• Good points.

    So this leaves us comparing the inefficiency of fixed-angle panels to the inefficiency of transmission over a grid. IIUC, grid inefficiency is huge. So wouldn’t it be wise to upgrade the home kits to add sun tracking and a motor?

    • Very few homeowners are going to want to pay even more for tracking. You’d also need more space to accommodate the swing of the array, and it also brings about more consideration for wind loads. Grid inefficiencies are still present with rooftop systems as well, as excess power is sent back to the grid.

      • Very few homeowners are going to want to pay even more for tracking. You’d also need more space to accommodate the swing of the array, and it also brings about more consideration for wind loads.

        In principle I think it would be ideal to have an easily accessible rooftop with a rooftop terrace so the rooftop space is functionally usable. But then indeed the frames that hold the panels up high enough so you could sit under the panels as they move would have to be rock-solid and thus costly. But quite useful if they could flip 180° when there’s hail (and unconditionally at nighttime). I’m brainstorming… is that crazy talk? Is this something that’s so cost prohibitive that the costs could never be recovered? It obviously wouldn’t be a budget option but some people might be willing to pay more just to have the luxury of extra terrace space.

        I’ve heard the down-to-earth lean budget approach is to have the panels on the ground because of the need to periodically quickly cover them up in hail storms and do various other maintenance tasks and adjustments. I don’t have ground space though.

        Grid inefficiencies are still present with rooftop systems as well, as excess power is sent back to the grid.

        IIUC, feeding the grid is more energy efficient than feeding batteries, which I assume is why you have an assumption of grid-feedback, correct? Alternatively, what about installing an extra big hot water tank so there is never unconsumed power?

        • Yes, a panel system like that would be very complex and costly, with little additional benefit. If it hails with the intensity to damage panels so often in a certain location, it’d probably be best to look at other generation alternatives.

          A hot water tank is still essentially unconsumed power, and likely worse in a warm climate, as heat will leak causing your cooling system to work harder.

    • The US national average grid loss is about 5%, which I figured would often be more than made up for by a lack of shadeing at larger installations. While grid losses are likely to increase as we move to renewables, that’s down to the fact that prime solar and wind spots tend to be much farther away from major north American cities than the suburban power plants that feed them currently. Given the density of said cities, rooftop solar just takes to much space to provide the necessary power for a taller building.

      While you can find some home scale ones with sun tracking, given the weight and foundation requirements they almost always need to be built on the ground, and do cost even more. You also have the aesthetic constraint, as while panels flat against the roof only annoy the most Nimby of Nimbys, large person sized poles like this are harder to hide, even if i think they look neat crystal flowers.

      https://www.solarreviews.com/content/images/blog/post/focus_images/41_Dual-Axis-Solar-Tracker-2-970.jpg

      Finally, tracking panels do have higher routine maintenance requirements, as there are now parfs that can move, wear, and jam. It doesn’t happen often, so one technician can dozens of square miles by themselves, but it takes a lot more time when you need to schedule around individual homeowners and a wide array of different types of install as compared to see a notification on the monitoring software when you get into work, hop in truck with a set of standerd replacement parts, go to panel and fix.