The tech exists today with solar, wind, batteries, transmission, hydro (pumped and otherwise), demand response, and electrification using heat pumps and EVs.
We're not waiting on anything groundbreaking, no heroic technologies are needed. There is no magic. It's just a matter of manufacturing/install capacity and funds. It's like insulation for buildings: not sexy, but it works and it's a known quantity. Work backwards from first principles based on how much energy the Sun delivers to the planet.
Yes, but in the winter wind is quite strong. There will be large storage needs, but mostly in the range of days. The electricity networks are connected all over Europe and production and consumption is already handled on an European level. This will extend more and together with the built-up of much capacity mean, that storage needs are not as high as some put them.
With wind they are other issues, it's very unpredictable far ahead, you need a lot of places to put them and it's already at maximum theoretical efficiency already after 100 years of evolution so there's not even a hope it will improve unlike solar.
At the end yeah you can get out of all of these issues by building 10x the required capacity, but that is reflected on the price and the space to build all of this though.
Wind generators still are getting more efficient - partly because they are still improving, especially in the generator part, but mostly because they are becoming larger and the wind gets stronger the higher you are above ground.
And yes, we will need to build more of them, many more. We don't need 10x of the required capacity, but more than the required capacity and then put the excess energy into storage. And of course it always will be a mix of wind and solar.
There was an article a while back talking about running a transmission line from Chile to China so summer, desert sun in Chile could be used to generate solar energy to heat China during the winter. I read (was an HN posted article) either within that article or in the comments that transmission losses would only be ~30%. I wonder if solar panels in North Africa could generate electricity to be consumed during German winter?
As an owner of a small domestic p.v. system, with lithium storage (not for economical reasons but to protect against eventual long blackouts) I with who say tech does not exist.
First there is a bit stability issue: when a load start to consume (zero feed in or on-battery/autonomous scenario) the solar inverter demand time (seconds!) to ramp up, when the load stop the solar inverter still feed too much power and we do not have ready available "super-condenser" (when a load pops-up) and "energy sponges" (when a load stop), the result is a not stable microgrid. IF we have a large enough grid where spike loads are not really spike than perhaps we can have stability but such kind of grid for solar and wind it's not there, the so called "smart grid" do exists only on paper.
Secondly all p.v. systems I know are sold as commercial product, but they prove to be more like initial prototypes, to make the microgrid stable software is much used, and in general it's correct name should be crapware. ModBUS RTU is the most monitoring-and-control universal protocol, in most cases with a crappy load of various kind of "bridge" (generally from classic serial to USB or to TCP) and being pull-based it's normally not suitable at microgrid scale. CanBUS is used for quicker communication and is used much like car's ODB: there is a standard, but almost all vendor "extend" it as they wish so interoperability is crappy. Even the most open of the p.v. systems I know of (Victron, witch base it's system on Debian and publish all the code) is an incredible pile of python glue code and scripts that can't be really considered "production ready". All such systems also are designed to live connected to the OEM, some are even hard to use without internet connectivity to their "home". Some even have hard-coded passwords with non-deactivable wifi, hard-coded per entire model series, like BYD batteries, an ideal target for a casual wardriver.
First: something can be "stored", for instance I have enough hot water to heat it just with solar (as long as there is enough day-to-day production), that's very good and ultimately easy, it's just about have enough space for a big boiler. Electricity on contrary can't be stored much: batteries are hyper-expensive and do not really last that longer. Most stressed batteries last 5 years, most 8 years, few perhaps can arrive at 10 but I'm not much convinced. Long story short, there is enough tech to power up few homes, built with proper insulation and implants etc to run that way, there is almost nothing at industry demand scale, not even to made such systems themselves.