energy

there is a lot in the media 

about family houses 

with solar cells and batteries 

selling electricity to the electric grid 

so if a family house 

has solar cells and batteries 

that turn solar energy into electricity 

during the day 

and store that electricity in batteries 

and then that house consumes that electricity 

mostly during the evening 

when everyone is home 

and if that house has excess electricity 

then that house sells that electricity 

to the electric grid 

during the evening 

when the demand for electricity is high 

so that more is paid for that electricity 

but media never writes about 

if an apartment has many batteries 

so that apartment 

could buy electricity from the electric grid 

when electricity is cheap 

and then sell that electricity back to the electric grid 

when electricity is expensive