A larger solar panel is recommended if you are wanting the battery to keep up with your power needs.
I have some code on the forum that allows you to put the Electron into Sleep Mode once the SOC hits 20% or whatever level you set it at to prevent the Electron from entering a shutdown state. The Electron will wake up every hour to check if the SOC has risen above 20% SOC before going back to your main code loop.
The Electron has a good charge controller built in and many have had success using it along with a solar panel input to recharge the LiPo battery including me.
I don’t see any benefit from you using the TP4056 charger over the TI PMIC chip that’s built into the Electron. Cutting the battery output off at 3v is basically a dead LiPo.
Using my code you can stop the Electron from pulling large amounts of power at any SOC level you choose while letting the solar panel recharge the battery until it’s charged back up.
The 1w Solar panel is not enough power to bring the Bring the Electron back online, it’s basically stuck in a dead battery state.