The demonstration is 5kW year round with insignificant consumption of fossil fuels everywhere with a climate about as good as Toronto or better, not having some

The demonstration is 5kW year round with insignificant consumption of fossil fuels everywhere with a climate about as good as Toronto or better, not having somewhere to put all the sunlight. Mid-winter in high latitude you get as little as 2hrs of sunlight/day (or 0 in the arctic, but hardly anyone lives there). If you live in the tropics, 10kW is probably fine. Also if you feel the need to use it up, electrolyzers are cheap and hydrogen is worth money. You can also store a great deal of energy in a few tonnes of NaOH and avoid using precious winter electricity for heating. You can also reshuffle the wind, solar and battery for your local climate, or wait a year or three for sodium batteries to halve the price.