We analyze 36 years of global, hourly weather data (1980–2015) to quantify the covariability of solar and wind resources as a function of time and location, over multi-decadal time scales and up to continental length scales. Assuming minimal excess generation, lossless transmission, and no other generation sources, the analysis indicates that wind-heavy or solar-heavy U.S.-scale power generation portfolios could in principle provide ∼80% of recent total annual U.S. electricity demand. However, to reliably meet 100% of total annual electricity demand, seasonal cycles and unpredictable weather events require several weeks’ worth of energy storage and/or the installation of much more capacity of solar and wind power than is routinely necessary to meet peak demand. To obtain ∼80% reliability, solar-heavy wind/solar generation mixes require sufficient energy storage to overcome the daily solar cycle, whereas wind-heavy wind/solar generation mixes require continental-scale transmission to exploit the geographic diversity of wind. Policy and planning aimed at providing a reliable electricity supply must therefore rigorously consider constraints associated with the geophysical variability of the solar and wind resource—even over continental scales.
The history of top down academic solutions to global energy system problems has not been positive. This does not bode well for the Jacobson solution. Global or even regional behaviour is too hard to coordinate. The one constant of energy and other commodity markets is that the low cost provider always wins. Payment for externalities can rarely be imposed on commodity producers.
StratoSolar reduces the cost of electricity to a fraction of electricity from fossil fuels. This makes it the lowest cost energy provider by a considerable margin, a margin sufficient to motivate rapid adoption. Being above the weather it does not suffer from the long duration intermittency that is the problem at the heart of the 100% renewables debate. It also includes a cheap energy storage option for nightime generation. It can be situated anywhere geographically. Were it proven, its significant cost advantage would rapidly make it the only energy source.
Renewables are still not cheaper than fossil fuel so they require carrots and sticks to promote adoption. The intermittency problems are still not exposed because their penetration levels are too small for the bad effects to show.
In a rational world, potential 100% renewable energy solutions would be explored. Unfortunately a political majority does not see an energy problem worth solving and the minority who do see a problem cannot agree on a path to viable solutions because they are focused on political solutions, not economically viable solutions.
By Edmund Kelly