Base load exists on the consumer side, as the minimum power the grid needs to operate during a cycle of X hours/days/weeks/years/whatever. It used to exist on the producer side since the cheapest power plants were also inflexible regarding ramping their power up and down coupled with high fixed costs and low marginal costs. Therefore, nuclear and coal was termed as base load providers, although it was purely an economical coupling leading to a term existing.
Nowadays with renewables undercutting everything they are the new base load providers, but it also brings new challenges for adapting the grids and consumers to more variability in the supply. This is our current world were the high fixed, low marginal cost power plant is pushed out of the market, as we are currently seeing globally. This is unless they can find a way to get their prices below renewables, but that is getting more and more unlikely with the steam cycle itself soon adding more to the KW/h cost than an entire renewable operation.
Actually, there is one thing, we need super capable and reliable super long distance power grid connections, maybe there's some progress on this front?
Because solar and wind absolutely are unreliable on a local front.
China recently finished a 3300 km UHVDC line from Xinjiang to the east coast with an expected loss of 1.5% per 1000 km.
