Our Global Space Heater
Transmission Control -
WARNING: I’m technically a layman when it comes to anything other than Computer Science so while I’ve tried to get the numbers right and double-check my ideas, I could be wrong for a variety of reasons. I don’t think I’m wildly wrong, however.
Some of you may remember the old Onion article Addressing Climate Crisis, Bush Calls For Development Of National Air Conditioner. It’s an absurd suggestion for thermodynamic reasons but it makes me think about how much heat we generate. Not just our bodies but everything we burn and all the electricity we use which ends up as heat. We are effectively running a rather large space heater all the time. Roughly 1.5×10^18 BTU from power generation and I’m not even sure if that includes fuel used directly for smelting and the like.
To put it another way, that’s 35 billion average space heaters, 5 for every man woman and child on the planet, running non-stop on their highest setting year-round.
Why don’t I ever hear anything about direct heating from fossil/nuclear power generation? I know it’s only about 0.06% of the solar energy that hits the Earth but I’d argue most of it ends up sunk in ways that prevents it from radiating away into space anywhere near as quickly. If that’s true then it’s somewhere on the order of 10% of the energy imbalance as it works out to around 0.1 watts per meter squared. The imbalance is somewhere around 0.85 watts per meter squared.
It’s a bit like running a space heater in a greenhouse and asking why it’s so damn hot. Only in this case the space heater is also simultaneously making the glass more and more effective at trapping heat.
Thinking about it this way might give additional motivation for fixing the horrific inefficiency of current power generation — even nuclear. About 2/3 of the total heat generated in power plants is wasted and sunk directly into the ocean or lower atmosphere.
It’d cost more to build plants that can capture that waste heat but it’d cut our greenhouse gas emissions by at least 3/5 (60%) and fuel costs by the same. The up-front costs are higher but 80% efficiency (vs current 33% average) is easily doable with a careful cascade design or cogeneration and it might be possible to get it as high as 98%. It would be cheaper in the long run even with increased maintenance costs of the more complicated systems. It should also reduce the cost of the fuel by reducing demand.
We do need renewables, of course. We absolutely shouldn’t stop pushing for that but we should at least look at trying to retrofit some existing plants to capture the waste heat and require it of new fossil and nuclear plants. It’ll probably make it easier to decommission an awful lot of old inefficient plants. Unlike direct replacement with intermittent renewables, it doesn’t risk disrupting grid stability.
The 1/3 we don’t waste immediately (generated electricity) also gets converted back to heat and sunk in the ocean or or air one way or another. That’s the hardest part to reduce since it directly impacts the economy and lifestyles but corporations could be encouraged to do waste heat recovery as well which would certainly help.
This is all technically called Thermal Pollution but that term usually only refers to the damage done to aquatic ecosystems by power plants. We need to realize it’s damaging the entire planet-wide ecosystem.