I look forward to the day when renewables provide >90% of our energy, and old men on the Internet are still bloviating that it can't be done. As for me, I'm looking at pallets of solar panels on eBay to expand our PV system.
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.
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.