Economy

Hydrogen electrolysis meshes well with batteries. Having enough solar to meet non-heating needs in winter even on cloudy days, means having way too much power in other 3 seasons when sunny. Enough solar and batteries to charge in winter cloudy days, and dump into heat storage (or some H2 electrolysis) on winter sunny days, would also let you overcool till 3pm in summer, and do electrolysis in 3 seasons.

Not only is H2 import/exportable for backup power or heating, but the electrolysis equipment is sizeable into truck containers that let them move around seasonally. Canada/Europe long summers is good time for electrolysis from winter sufficient solar. Southern US, can be good enough other seasons, but southern hemisphere can gain more from other hemisphere's winter.