Only in the surge moments.

So what? This still drives down average electricity prices, which is what really matters. Right now oversupply only really happens on weekends and during nights, when demand is low, and there are at least good condistions for renewables. For renewables to actually lower prices even more, you want those moments to extend. The issue is that the generation costs for fossil fuels are significantly above renewables, which are basicly at zero. Due to price being set by the most expensive plant currently producing you will not see low prices from renewables unless they meet demand. Most of the time they are unable to do so, unless demand is low and we have the higher fossil fuel prices.

In other words, we need more surge moments.

If the consumers could adjust as fast at it’s needed, there would be no negative prices etc.

This means inefficiency.

Actually the planned system is one with a bit of inefficency. When you built just enough renewables to produce enough electricity for the entire year, the electricity storage you need is insanly large. As you are basicly forced to built storage able to store electricity from sunny and windy summer days until no wind cloudy winter days. So from perfect conditions to absolutly worsed. The thing is there is usually some renewable electricity available at all time. A bit of wind somewhere and the clouds go away a bit during the day. So it is never totally zero for days and there are a lot of just okayish days. So you can use the power from just good days, for the really bad ones as well, which lowers your storage a lot. In fact most of the storage needed is basicly for a single night, which allows you to go most of the summer without fossil fuels at all. Basicly you overproduce a few percent more power, but cut your storage needs by 90% or so. To go most of the way you need storage for a single night. The rest can be long term storage, with less efficency like hydrogen burned in old gas power plants or biomass in coal plants. Obviously hvdc grids help a lot as well and they are built at speed. Norway and Sweden have insane storage capacity in form of hydro, which is intressting for the countries further south for example. Italy, Spain and Germany also have very different weather, which means different renewables power generation at times. That is also currently expended by a lot basicly everywhere in Europe.

In other words, this is a minor problem of loosing a few percent of generation for a bit until the systems are finished and a lot of the are built and planned right now. Without those prices the intrest in it would be lower thou. In terms of problems this is a very nice one to have and honestly good news. Certainly beats having to use fossil fuels all the time.