<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>qbasic_forever</author><text>RTGs have been around since the 50&amp;#x27;s and 60&amp;#x27;s: &lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;en.wikipedia.org&amp;#x2F;wiki&amp;#x2F;Radioisotope_thermoelectric_generator&quot; rel=&quot;nofollow&quot;&gt;https:&amp;#x2F;&amp;#x2F;en.wikipedia.org&amp;#x2F;wiki&amp;#x2F;Radioisotope_thermoelectric_ge...&lt;/a&gt;  For example Russia used them to power lighthouses in super remote parts of their coast.  Space probes, mars rovers, etc. use them too.</text><parent_chain><item><author>drraj32</author><text>Just got me thinking:
What would it take for us to get to a point where there are small, safe nuclear powered &amp;quot;batteries&amp;quot;, that can supply enough electricity for a building.</text></item></parent_chain></comment><story><title>Nuclear-Powered Cardiac Pacemakers</title><url>https://osrp.lanl.gov/pacemakers.shtml</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>klodolph</author><text>It would take some kind of complete revolution. It’s not happening.&lt;p&gt;These batteries have very poor power density and are very inefficient. The advantages of nuclear-powered batteries are:&lt;p&gt;- They generate power over a long time, decades,&lt;p&gt;- They generate some heat.&lt;p&gt;They don’t generate much power. If you have a building, you would definitely think of a nuclear RTG as a “very shitty battery”, and that’s even if you don’t care at all about radioactivity.&lt;p&gt;Thinking of these as a “battery” is also a bit misleading, IMO. These are really just small power plants, which generate heat and turn the heat into electricity. The heat is powered by radioactive decay of Pu-238, and then turned into electricity with the extremely inefficient Seebeck effect. If you had a source of heat you wanted to turn into electricity, it’s much more efficient to use that heat to turn a turbine which is connected to a generator. And if you want an efficient, cost-effictive turbine, you make it big. At that point, you have a power plant.</text><parent_chain><item><author>drraj32</author><text>Just got me thinking:
What would it take for us to get to a point where there are small, safe nuclear powered &amp;quot;batteries&amp;quot;, that can supply enough electricity for a building.</text></item></parent_chain></comment><story><title>Nuclear-Powered Cardiac Pacemakers</title><url>https://osrp.lanl.gov/pacemakers.shtml</url></story>