The BIGGEST problem with clean energy

The critical problems of storage become vastly simpler and less expensive, and therefore easier to implement, if you don't try to get to 100% intermittent renewables.  Providing even 20% of our electricity from nuclear would be a huge help, and between uranium and thorium fuel cycles, along with reactors burning existing nuclear waste for energy, we have enough fuel for many centuries if not millennia.

The cost difference of storage needs between 80% renewables and 100% is huge.  For example, a major study on storage needs for California by The Clean Air Task Force (a respected climate change charity and think tank), found that at 80% renewables you would need 9.6 million megawatt-hours of energy storage and 36.3 million mWh at 100%.  Almost 4 times as much storage just to get the last 20%.   Maintaining that storage reserve (a great deal of it unused most of the time) is expensive and that cost has to be paid for by electricity users, resulting  an an effective  net production cost of $1612 per mWh at 100% renewables.  Compare that to about $160 pr mWh,  the high end of costs for electricity from new nuclear power plants... often derided as 'too expensive.'  In reality, it is *not* including nuclear in our clean energy mix that is too expensive.  It is certainly possible to make 100% renewables work.  It just takes even longer than building new nuclear plants and costs 10x as much.

As for safety, the reality is that we have been misled for decades about nuclear power by activists who, however well meaning, can't or won't understand that nuclear power and nuclear weapons aren't the same thing. Even when waste and accidents are considered, the number of lives lost per mWh for nuclear is comparable to that from solar and wind power, all vastly less than the death toll from fossil fuels.  Just the small particulates alone from coal kills as many people every 7 hours as the high end calculation of the  eventual total death toll at Fukushima.   The problems of waste are far more manageable when you don't use 5% of the energy in the fuel and call the rest waste like we do now.  Instead use it for fuel in other type of reactors.  Nuclear waste is as manageable a problem as the toxic heavy metal and other chemical pollution produced making solar panels. And both are trivial compared to the problem of climate change that both help address.