<instructions>Your goal is to analyze the following comment and estimate how highly it will be upvoted by the Hacker News community.</instructions><comment><author>elihu</author><text>&amp;gt; In this context, solar and wind are atrocious and a total disaster because they have massive land-use requirements.&lt;p&gt;No, they don&amp;#x27;t.  There is a lot of empty land in the world that isn&amp;#x27;t useful for people to live in or to grow crops due to lack of rainfall, which also makes those sites more valuable for solar energy.&lt;p&gt;We&amp;#x27;d consider a utility-scale solar array that&amp;#x27;s a couple square miles to be absolutely huge, but plotted on a map of, say, the United States it would be a barely visible dot in a massive sea of land-that-isn&amp;#x27;t-devoted-to-solar-power.  The Earth is very big, and when you get outside the areas where people congregate there&amp;#x27;s a lot of wide open spaces.&lt;p&gt;This says that US electricity consumption was 3.9 trillion killowatt-hours in 2019:&lt;p&gt;&lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;www.eia.gov&amp;#x2F;energyexplained&amp;#x2F;electricity&amp;#x2F;use-of-electricity.php&quot; rel=&quot;nofollow&quot;&gt;https:&amp;#x2F;&amp;#x2F;www.eia.gov&amp;#x2F;energyexplained&amp;#x2F;electricity&amp;#x2F;use-of-elect...&lt;/a&gt;&lt;p&gt;39 quadrillion watt hours divided by (365&lt;i&gt;24) gives us average power consumption in watts.&lt;p&gt;Let&amp;#x27;s say a pretty good solar panel gets 100 watts per square meter, then reduce that to 30 to account for night-time. If we divide average power consumption by 30 watts per meter and divide by 1,000,000 to convert to square kilometers, we get:&lt;p&gt;Prelude&amp;gt; (((3.9 &lt;/i&gt; 1000 * 1000 * 1000 * 1000 * 1000) &amp;#x2F; (365&lt;i&gt;24)) &amp;#x2F; 30) &amp;#x2F; (1000 &lt;/i&gt; 1000)
 14840.182648401827&lt;p&gt;So, about 15,000 square kilometers of solar panels would satisfy current US electrical needs.  Let&amp;#x27;s double that to be conservative, that&amp;#x27;s 30,000 square kilometers.  Sounds like a lot, right?  That&amp;#x27;s a rectangle 100 km by 300 km.  It&amp;#x27;s slightly more than 10% of the land area of Nevada.  Definitely big, but attainable.  Compared to the land we use for farming, it&amp;#x27;s barely anything (and it can be done in places that we don&amp;#x27;t farm).  And in practice it would be spread out, not just in one place.  And it also assumes we get 100% of our power from solar, which we wouldn&amp;#x27;t.</text><parent_chain><item><author>macspoofing</author><text>&amp;gt;There are plenty of sites that would happily accept more nuclear being built, but all other forms of energy have undercut the cost of nuclear.&lt;p&gt;Honestly ... it isn&amp;#x27;t just about cost. Nuclear is expensive but it isn&amp;#x27;t prohibitively expensive. The big picture is we know that nuclear can power an economy, it does not emit global warming gasses, and also places a tiny footprint on the surrounding ecosystem.&lt;p&gt;Solar and wind cannot power an economy. But let&amp;#x27;s pretend they can so as to not get bogged down on this point. Let&amp;#x27;s also pretend they are non-trivially cheaper than nuclear. Even under those assumptions nuclear still wins in my eyes.&lt;p&gt;Global warming is only one environmental problem we have to solve and it may not be the most important one either. The other one is regular environmental collapse due to needing to support 7-10 billion people. In this context, solar and wind are atrocious and a total disaster because they have massive land-use requirements (land-use around mining for necessary materials, deployment and maintenance of the collectors, and finally land-fill once out of use). And they will always have those horrendous land-use requirements because solar and wind are diffuse energy sources. Worse, we&amp;#x27;re going to need to increase solar and wind collector production by several orders of magnitude (and come up with a battery technology that doesn&amp;#x27;t exist today) to fully support a fossil fuel transition. What cost do you think the environment will bear for that compared to nuclear infrastructure?</text></item><item><author>epistasis</author><text>Articles like this miss the main point and instead focus on culture war material. There are plenty of sites that would happily accept more nuclear being built, but all other forms of energy have undercut the cost of nuclear. It&amp;#x27;s no longer cost competitive, and places like China that adopt a &amp;quot;let&amp;#x27;s try everything and see what works best&amp;quot; approach have heavily pulled back on nuclear.&lt;p&gt;The issues aren&amp;#x27;t safety, waste, and environments opposition. There are plenty of climate hawks that support nuclear too.  It&amp;#x27;s all excessive costs.&lt;p&gt;They briefly mention the cooling retrofits for Diablo Canyon in San Lui Obispo, but they don&amp;#x27;t mention that they bids from Bechtel to simply build a modern cooling system were all billions of dollars of expense. Just the cooling system is more expensive than alternatives.&lt;p&gt;And this is a trend we will see in the future. For primary generation of electrons, steam based thermodynamic cycles are pretty much obsolete. The number I typically hear is that it&amp;#x27;s $1-2W to build, say, a cooling system for coal steam. A nuclear plants cooling is pretty much identical. Solar and wind are going to undercut that cost very soon.&lt;p&gt;So the name of the game is now storage. Attaching four hours of storage to a solar generation farm, just enough to get through the duck curve, is now slightly cheaper than coal.&lt;p&gt;The best estimate of what the cheapest possible future grid looks like is: solar&amp;#x2F;wind capacity at 4x of total demand (thermal generators are roughly at 2x on the current grid), with 3-4 days of storage. This translates to world with abundant energy, at certain times, that&amp;#x27;s generated at zero marginal cost.  There are still lots of transmission costs however. The future of energy is all about spatial and temporal arbitrage of renewable electrons.</text></item></parent_chain></comment><story><title>Activists who embrace nuclear power</title><url>https://www.newyorker.com/tech/annals-of-technology/the-activists-who-embrace-nuclear-power</url></story>
<instructions>Your goal is to analyze the following comment and estimate how highly it will be upvoted by the Hacker News community.</instructions><comment><author>brightball</author><text>The thing about land use that always got me was that solar can be implemented as a roofing system in parking lots. We have a lot of parking lots out there.&lt;p&gt;IMO the model used for parking at Lego Land looks like the ideal approach for solar expansion to me.</text><parent_chain><item><author>macspoofing</author><text>&amp;gt;There are plenty of sites that would happily accept more nuclear being built, but all other forms of energy have undercut the cost of nuclear.&lt;p&gt;Honestly ... it isn&amp;#x27;t just about cost. Nuclear is expensive but it isn&amp;#x27;t prohibitively expensive. The big picture is we know that nuclear can power an economy, it does not emit global warming gasses, and also places a tiny footprint on the surrounding ecosystem.&lt;p&gt;Solar and wind cannot power an economy. But let&amp;#x27;s pretend they can so as to not get bogged down on this point. Let&amp;#x27;s also pretend they are non-trivially cheaper than nuclear. Even under those assumptions nuclear still wins in my eyes.&lt;p&gt;Global warming is only one environmental problem we have to solve and it may not be the most important one either. The other one is regular environmental collapse due to needing to support 7-10 billion people. In this context, solar and wind are atrocious and a total disaster because they have massive land-use requirements (land-use around mining for necessary materials, deployment and maintenance of the collectors, and finally land-fill once out of use). And they will always have those horrendous land-use requirements because solar and wind are diffuse energy sources. Worse, we&amp;#x27;re going to need to increase solar and wind collector production by several orders of magnitude (and come up with a battery technology that doesn&amp;#x27;t exist today) to fully support a fossil fuel transition. What cost do you think the environment will bear for that compared to nuclear infrastructure?</text></item><item><author>epistasis</author><text>Articles like this miss the main point and instead focus on culture war material. There are plenty of sites that would happily accept more nuclear being built, but all other forms of energy have undercut the cost of nuclear. It&amp;#x27;s no longer cost competitive, and places like China that adopt a &amp;quot;let&amp;#x27;s try everything and see what works best&amp;quot; approach have heavily pulled back on nuclear.&lt;p&gt;The issues aren&amp;#x27;t safety, waste, and environments opposition. There are plenty of climate hawks that support nuclear too.  It&amp;#x27;s all excessive costs.&lt;p&gt;They briefly mention the cooling retrofits for Diablo Canyon in San Lui Obispo, but they don&amp;#x27;t mention that they bids from Bechtel to simply build a modern cooling system were all billions of dollars of expense. Just the cooling system is more expensive than alternatives.&lt;p&gt;And this is a trend we will see in the future. For primary generation of electrons, steam based thermodynamic cycles are pretty much obsolete. The number I typically hear is that it&amp;#x27;s $1-2W to build, say, a cooling system for coal steam. A nuclear plants cooling is pretty much identical. Solar and wind are going to undercut that cost very soon.&lt;p&gt;So the name of the game is now storage. Attaching four hours of storage to a solar generation farm, just enough to get through the duck curve, is now slightly cheaper than coal.&lt;p&gt;The best estimate of what the cheapest possible future grid looks like is: solar&amp;#x2F;wind capacity at 4x of total demand (thermal generators are roughly at 2x on the current grid), with 3-4 days of storage. This translates to world with abundant energy, at certain times, that&amp;#x27;s generated at zero marginal cost.  There are still lots of transmission costs however. The future of energy is all about spatial and temporal arbitrage of renewable electrons.</text></item></parent_chain></comment><story><title>Activists who embrace nuclear power</title><url>https://www.newyorker.com/tech/annals-of-technology/the-activists-who-embrace-nuclear-power</url></story>