2020

No one can get past 15% of their electricity as solar and wind on a large scale. Europeans are building coal and nuclear plants at 15% solar and wind because of the wall.

Of course, the wall at 15% is due to fluctuations. There is no realistic answer to the fluctuations caused by solar and wind, because the fluctuations are too rapid and extreme for back-ups and electrical infrastructures only allow 15% fluctuations as an outer limit.

Therefore, there must be 100% backup, and it must be instantaneous, for anything over 15% renewables as solar and wind, which is never going to happen on a large scale.

Supposedly, Iowa is an example of 36% wind power. The number has no meaning, because the grid is linked to lines going into Illinois and Wisconsin, where it is about 1% of the electrical energy, and some of it goes into ethanol production which presumably tolerates inconsistencies.

Transmission lines are an additional problem, because long lines lose 50% of the energy that goes through them to heat; and short lines lose 20%. Engineers design those loses in, so they don't have to produce so much metal. If the loss were reduced from 50% to 25%, twice as many lines would be needed.

Greens are unconcerned about costs and assume society should pay any price including more transmission lines. But the reality is that transmission lines are so expensive that consumers will not tolerate the expense of more transmission lines.

As a general rule, transmission lines cost about as much as the generating systems for commercial solar and wind by the time the lines are 300 miles long. It means, if transmission lines are constructed, they double the cost of installation every 300 miles of length. This problem has not been highly noticeable, because the small amounts of solar and wind at this time piggyback on existing infrastructure. When new lines must be constructed, they are so expensive that they never allow expansion to the levels required for going beyond the 15% wall.

In other words, even though the activists say, throw any amount of money at the problem, it never happens. Transmission lines are too expensive. In fact, a shortage of long transmission lines is creating a national security problem, while society will not invest in long lines because of the extreme expense and environmental damage.

After Germany built off-shore windmills, they could not send the electricity to southern Germany where it was needed, because the transmission lines were environmentally unacceptable. What they eventually did, I don't know.