There's no doubt that clean energy stocks generally are in bubble territory. But some of the comments in this story are ludicrous:
“As much as 25 to 60 per cent of the energy generated in a renewable system is consumed internally, compared with three per cent for a modern gas plant,” they wrote. “According to our models, wind and solar would mark the first time we have seen a widespread shift into a much less efficient source of energy conversion.”
Gas plants in the U.S. average 40% efficiency converting heat energy to power. The very best combined cycle plants, with the most sophisticated heat recovery systems, reach 60% efficiency. The second law of thermodynamics cannot be circumvented except in the imagination. Once generated the power losses from a gas plant, solar and wind power are much the same.
"25-60% of the energy generated in a renewable system is consumed internally" is flat out false. In commercial solar systems there is in the order of 1-2% loss in solder and busbar connections. If wiring is properly sized there is less than 1% local line loss between where the power is generated and connection to the grid, whether solar or wind power. They may be talking a home PV system, which loses up to 30% of generated power in line, inverter and battery loss but to compare home PV to grid scale natural gas plants is apples to oranges.