Re: the "grid storage" issue.
1. The electrical supply is not 100% stable. There are substantial voltage fluctuations in any 24 hour period. Line stabilizers are needed to shield sensitive equipment from voltage sags and spikes.
2. Demand is predictable. In that same 24 hour period, people get up, shower, turn up the heat, and go to work. Temperature forecasts are a good predictor of heating and cooling load. Wind forecasts tell you how your wind turbines will perform, overcast conditions affect solar arrays, and power system management tracks all available factors. Flexible generation capacity can be brought online on a daily schedule. Natural gas turbines can be brought online in minutes. Hydro turbines are right behind, limited only by how fast they can open the penstock without blowing the power house apart.
3. While household electrical demand is constant within predictable limits, major industrial users have to coordinate with their power suppliers before they start up major equipment like steel induction furnaces. Except in emergency, they will also coordinate shutdown.
4. The only real time online storage is inertial. Increasing load on a generator will cause it to slow down, but there is spinning mass, sometimes substantial, that resists slowing. Utilities generally keep the resulting voltage sag within 5%. Anything over 10% is a brownout. 1% to 2% is negligible. Let's hear it for angular momentum. Likewise, a generator can be spun up and ready, but uses very little power until it actually generates some.
Oh, and you notice I don't use the 'G' word, which is nonsense noise.