We actually do have a Balkonkraftwerk im Garten :-)
Now that the sun is out for longer periods each day we are "wasting" energy to the grid a lot. I don't really see how to capture that energy though.
1. Buying a battery quickly shifts the break even points to decades. Without a battery I estimate 3-4 years.
2. I would love to heat water, but renting a place limits my options a lot. I was looking at electrical boilers to supplement the gas heater. But we are limited on space for small heaters below the sink and big heaters in the main water path. (Also we can't change the plumbing for legal reasons.)
3. The next best thing is some imaginary insulated water heating kettle that I can control to only use exactly the excess energy. No idea if such a thing exists.
You probably thought of this already but we mostly do load shifting. If you have moderate PV output (like with balcony solar) that can probably use up most of your production.
Consider running the dishwasher (if you have one) or washing machine / dryer (if you don't dry that in the sun directly) during the day.
Granted, we work from home _a lot_ and also have an EV so it's a lot easier to do load shifting for us, but just shifting the dishwasher and washing machine to 'sunlight hours' already made a pretty decent difference.
Yeah, we do that. Given that most home appliances use more than 800W (even in Eco modes) we often use more than our production.
E.g. our washing machine uses 1000W over a prolonged period of time which would be perfect to run on a sunny day. But it does so by switching the 2000W heating element so it averages to 1000W ...
So we repeatedly export 800W (without any form of reimbursement) and import the missing 1200W back.
And that is the case for all of our appliances. (I have a sensor to monitor that)
Don't know if more modern machines are better in this regard, our machines are about 5 years old now.
edit: I don't want to sound bitter about it. The Balkonkraftwerk works perfectly fine to power our base energy load.
Now that the sun is out for longer periods each day we are "wasting" energy to the grid a lot. I don't really see how to capture that energy though.
1. Buying a battery quickly shifts the break even points to decades. Without a battery I estimate 3-4 years. 2. I would love to heat water, but renting a place limits my options a lot. I was looking at electrical boilers to supplement the gas heater. But we are limited on space for small heaters below the sink and big heaters in the main water path. (Also we can't change the plumbing for legal reasons.) 3. The next best thing is some imaginary insulated water heating kettle that I can control to only use exactly the excess energy. No idea if such a thing exists.