GoSeigen wrote:dspp wrote:Since China has 9.5 million km2 this can easily be done. It is just 0.6% of land area.
Similar sums show that pretty much any country can do it. So does practical experience - Portugal went all winter with zero coal use in the last winter.
regards, dspp
Why China? The problem energy consumers are in the USA; how does 100% solar look for them and what if you include conversion to solar from fossil fuel for heating and vehicle use (since the claim is that fossil fuels can be rendered obsolete)? I could do this calculation but as you've already had a go would you mind repeating for the US? Thx, GS.
GS
The reason China was being discussed because apparently Musk made some statements in a utube video about what could be done, and others here were sense checking them and saying he was wrong. I've not listened to what Musk actually said, but I could see that the sensecheck was itself wrong as I do these sums in my day job occasionally. Hence my doing a simple calc to show reality.
USA consumes 3,911 TWh/yr elec. Assuming same yield as my Dorset solar that is 22,325km2 of solar, or say 44,650 km2 of land. That is 0.5% of USA land which is 9.8 million km2.
These numbers are annual numbers. To actually design a system you wouldn't do it all solar, or all wind, etc. But what they illustrate is that it is technically feasible. To actually design an optimal system you come to me (or someone similar) and I/we do lots of fancy sums to calculate the ideal mix of wind, solar, storage, hydro, nuclear, fossil, etc to give a particular confidence level of "power on demand" (which of course is always less than 1.0 even in a conventional system) and the corresponding price to the user.
It is easy. It is being done. It is increasingly cost-effective. It is the future.
regards, dspp