The markets and incentives are pretty screwy right now, but overbuilding solar is probably one of our best strategies at preparing for the future in the current moment. There are a number of reasons for this, in no particular order:
Batteries still need to come down in cost before they are economical for residential energy storage. But once they become cost effective, they are fairly easy to add to existing installations, where as adding additional panels is much more difficult.
EV adoption is going to mean much more demand in the future. And the nice thing about EV's is they are great for flex demand, i.e. we can charge them when the sun is out.
Electrification of homes means we need to provide enough capacity to meet demand in both the summer and winter months. Due to solar output being much lower in winter, and because solar is so cheap, it makes sense to build a large enough system to cover winter demand (it might not be the most economical decision right now for the individual, but this is the best path forward for getting to a 100% carbon free grid).
Basically, our best strategy in the current moment, with current incentives is to just massively overbuild solar. As you have discovered, this is a bit wonky in practice, especially thanks to utilities pushing back heavily on residential solar (see PG&E). In the meantime, maybe consider taking the $0.01 payout, or get a bitcoin miner, or better yet use your excess electricity to power a DIY algae farm and help remove CO2 from the atmosphere.
Solar panels have a ~20 year life and are also getting cheaper as time goes on. Maybe building mounting capacity for them is smart, but it's not necessarily smart to more panels than you will properly use. You can buy more panels later if it actually becomes smart to use them and you have a use case.
The panels are dirt cheap compared to the other costs (installation, permitting, inverters, etc...). I suspect that the installation costs and any permit modifications required during the expansion would greatly extend the ROI timeline vs just including the panels in the initial install. If you were really trying to save costs, maybe you could significantly undersize the inverter, as those tend to only last 7-8 years, and you would only suffer losses during the peak hours in the summer months when you are likely to have way more energy than needed.
More generally, overbuilding is not really going to be economical right now. We do not have the proper incentives in place for that. But from what I can tell it is our quickest/cheapest path to a sustainable grid, and that likely means we will need to adjust our consumption patterns to account for the absurd amount of excessive power we will have in peak solar months (usually late spring). This means we will need to start developing power intensive applications that can take advantage of free (and possibly negatively priced) power. So if you want to get ahead of the curve, put a massive solar system on your roof and start thinking up interesting ways to use that excess power.
Batteries still need to come down in cost before they are economical for residential energy storage. But once they become cost effective, they are fairly easy to add to existing installations, where as adding additional panels is much more difficult.
EV adoption is going to mean much more demand in the future. And the nice thing about EV's is they are great for flex demand, i.e. we can charge them when the sun is out.
Electrification of homes means we need to provide enough capacity to meet demand in both the summer and winter months. Due to solar output being much lower in winter, and because solar is so cheap, it makes sense to build a large enough system to cover winter demand (it might not be the most economical decision right now for the individual, but this is the best path forward for getting to a 100% carbon free grid).
Basically, our best strategy in the current moment, with current incentives is to just massively overbuild solar. As you have discovered, this is a bit wonky in practice, especially thanks to utilities pushing back heavily on residential solar (see PG&E). In the meantime, maybe consider taking the $0.01 payout, or get a bitcoin miner, or better yet use your excess electricity to power a DIY algae farm and help remove CO2 from the atmosphere.