There was an enegry debate here a couple of months ago and it was suggested that the future of enegry is everyone will have a solar panels and a battery which is charged by the sun.

Once you think about distributed power, the need to generate mass amounts in one place seems to be less important, though having access to cleaner and safer ways of doing so are still good things as no doubtsome of us will still rely on the grid sometimes.

Give us decent batteries and all will be well. My parents just scrapped their solar set up. Summer days in the Bay of Plenty, New Zealand, provides enough sun to have the charging switch off at about 9am, batteries full. Big Mac Pro, lots of IT gear, coffee machine, vacuum cleaner etc all used normally. No problem. But come winter the batteries would be perilously low, risking damage. Days and days of torrential rain prevented any meaningful charging. The ability to store more power economically would be so very handy. The panels would provide vastly more power than was used during a year, but were uneconomic due to not being able to feed it back to the grid (!!?!) and not being able to store enough. I'd say that decent power storage was a bigger problem than the generation.

is it possible to somehow convert the power gathered during summer and spread it out for use during winter (when there is less sun), by say, electrolysing water to produce hydrogen and then use that as a chemical store of fuel?

if you could feed it to the grid, hydro and coal and natural plants could be throttled down or some units shut down. I don't know about nz energy mix but I assume they have lots of hydro power. This is the natural straight forward way if doing it, not installing heavy batteries at homes. You can simulate adding different power sources to the grid with commercial software.

I'm sick and tired of this "but it's intermittent" canard.

No. As the previous poster wrote, "The ability to store more power economically would be so very handy."

Distributed power may work in sparsely populated areas, but urban areas have a too high population density for that to work. That is even the case for whole countries, like Germany, where all the available renewable energy resources amounts to no more that 25 % of the current energy uses. That number is even unrealistically high, requiring to cover almost any available surface with solar panels and all usable spots with wind turbines etc.

Thus in such areas, a centralized grid is needed to transport electricity from where it is available to where it can be used. This can be nuclear, but it can also be renewable energy, e.g solar energy from southern Spain and Sahara or wind power from Norway in the case of Germany, but to produce everything locally won't work a lot of places.

Solar (and Wind) power both are not good base load power solutions - primarily because battery tech to store power for long periods isn't practical yet, and due to their cyclical availability.

Also to note - the framework to transfer/sell power from an area of excess to another (i.e., P2P power supply) is nonexistent, let alone trying to merge that with centralized power (for right now, you can only really sell your power to the utility - and they don't like it because it costs a lot for them to manage it).

Solar/Wind are very very important to a diverse and strong power mix (and for low stable energy prices), but combined with fission (or fusion once it's feasible) or other traditional power sources, you get a lot more stability and predictable power generation.