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Comment by undreren | Hacker News Reader

All chemical energy available through coal and oil stored in the earth is the product of a massive amount of highly ineffecient capture of energy from sunlight. [0]

All wind is caused directly by unequal warming of our planet through sunlight. The average hurricane individually releases more energy than entire world population has exhausted, since the dawn of time. [1]

Sunlight is plenty enough. The problem is cheap, clean storage.

[0] - https://en.wikipedia.org/wiki/Photosynthesis

[1] - https://science.howstuffworks.com/environmental/energy/energ...

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Another problem is energy density as I said. How much solar energy can you harvest from one square kilometer? I am so surprised that people just handwave this basic fundamental limits away and don't realize that we would have to build solar panels on an enormous percentage of planet for it to be able to replace fossil fuels.

Also managing the lifecycle and production of these panels is another issue. And don't forget that you still need to grow crops somewhere.

Currently only less than 2 % of the energy we use comes from solar energy and 87 % comes from fossil fuels. The cost of replacing the infrastructure is enormous and there is not much incentive to do it as long as we have plenty of cheap oil (which is going to stay with us for at least another century according to estimates).

Why is it so unimaginable that we will still be using oil in 100 years? It might not be 87 % as it is today, it might be 30 % but I am very sceptical that we will be able to completely replace the infrastructure we have build in the last 200 years.

> Another problem is energy density as I said. How much solar energy can you harvest from one square kilometer? I am so surprised that people just handwave this basic fundamental limits away and don't realize that we would have to build solar panels on an enormous percentage of planet for it to be able to replace fossil fuels.

What are you talking about? From Elon Musk's TED talk, this is the area of solar panels required to power all of the US.

http://sustainsubstance.org/images/storage/2015-musk-bluesqu...

A single solar farm of 1km sq can provide enough power for several ten thousand homes, and we have several million square miles of unusuable land lying around in the countries that receive the most sunlight, so land isn't the issue.

That doesn't include solar panels that could actually be installed on the homes. A single roof entirely covered by solar panels can power a LEED-certified home when used in conjunction with battery storage. (Most solar panel setups do not cover the entire rough but still provide sufficient power for all but the most intensive uses, like refrigerators and A/C.)

Farmland, by and large, isn't the best land for solar panels anyway, so the two would generally not come into conflict.

The Mojave Desert. It’s 48,000 square miles and almost uninhabited. We need 2% of that for almost 1000 sq miles. The Trump admin has approved that land for solar but the environmentalists are fighting hard against it, making bidding companies wary that it won’t be worth it. The location is perfect to supply Vegas, Phoenix, LA, and Texas easy. And can also do NorCal and more. It’ll get you 167GW capacity of solar. More than our current wind and solar combined and almost 10% of electricity generation of the country. Rooftop solar on the 30 biggest businesses in America would also yield a ton of solar, read a study the other day on that.

But...you do have a point even though the first part was wrong. Honestly, anything above 50% solar and wind is useless. Need to make up that cost via hydro, nuclear, or storage.

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