Excess Electricity

[threepets]

When the Batteries are at 100% SOC and the house is only using 80W where does the excess electricity go? The panels produce 3-4 Kw all day long in the sun and 4-6 00W when it's overcast.
Where is that electricity going??

 

[sunshine_eggo]

Heat.

80% of the energy hitting the panels is converted to heat. As less power is drawn from the panels, more of that energy is converted to heat until 0W is drawn where 100% of the energy is converted to heat - where they behave like most things exposed to solar... they heat up.

Panels are not unrestrained sources of power. They are simply sources. Anything drawing power from them is a load.

A battery sitting there doesn't try to discharge unless a load is applied.

Plugging a 60W light bulb into a 120VAC outlet capable of delivering 1800W only draws 60W.

Most residences are fed by a 200A/240VAC panel... that's 48,000W... where does that go? nowhere. A load must be applied to draw power.

 

[Ampster]

It is not being produced if the inverter is not pulling current from the panels. The inverter only pulls what it needs to charge batteries, serve loads and cover overhead. Same thing is true for sunlight falling on your backyard except for the heat it provides. Your panels will also get warm and produce voltage but only enough current which the inverter pulls. @sunshine_eggo beat me to the answer with a more detailed explanation.

 

[threepets]

Thank you for helping me understand