As you know , there is an answer and it isnot cheap , several options are available , but as far as i know all involve a battery ....
I assume something official and easy must be available soon (without batteries) , cause since 2009 for exampe in Germany you are allowed to use your PV produced electricity at home directly and get paid for the units you use yourself with a fixed tariff for 20 (?) years
But as far as i know nobody manages (many want to) to control their use
Since 2009 it then results in a better payback then for just exporting and tendencies are that importing units will get more expensive
So ideas of how to use all self-produced electricity will follow ( even if that will result in stupid waste of electricity

)
Billi