so the goal is to transport renewable energy from the point of production (e.g. coastline for offshore wind) to the point of consumption (e.g. big factory 300 miles from the coast).
what is the cost of doing this? when comparing different technologies. i.e. you can just build a cable and transport the electricity through that, or you convert the energy into hydrogen at the point of production, then pipe that hydrogen gas through a pipeline to the point of consumption. many big consumers can naturally consume hydrogen instead of electric power anyways, for example large steel mills. they require power for heating and reduction, but in both cases, both power sources can be used (for reduction, electrolysis vs. chemical reduction).
it’s well-known that the LCOE (levelized cost of electricity) for solar and wind is around 6 ct/kWh (citation needed, i’m citing from memory). so what is the cost of transporting that electric power over 300 miles? according to the diagram, it’s 4 ct/kWh over 1000 miles, so probably 1.33 ct/kWh over 300 miles using wires. so it makes a small part of the cost.
meanwhile if you use hydrogen, you have around a 70% conversion+storage efficiency (electric power -> hydrogen, plus storing it in an underground cavern) (source: this paper and german wikipedia about hydrogen storage). so to produce 1 kWh hydrogen, you need 1.4 kWh electricity at the cost of 1.4 * 6 ct/kWh = 8.4 ct/kWh. transmitting it over the pipeline, meanwhile, costs almost nothing, as seen in the diagram.
so in summary, producing+storing+transmitting hydrogen is slightly more expensive than just producing+transmitting electric power, but that already includes the storage cost. for electric power, you need additional batteries which i’m too lazy to write about now. just to give you an idea.
Pipelines are cheap because we already build a lot of them. We already use them to move multiple products. It’s a somewhat generic technology (which is very impressive, dont get me wrong).
I’d be interested to learn how the capex breaks down for the HVDC lines. Is it labor? Procurement? Those can both be optimized with scale. Expand the qualified workforce and incentivize competition among suppliers. If it’s raw material cost it might be a little harder. I imagine right of way costs are also quite a bit higher owing to the large footprint. But then once you acquire the RoW it stays there in perpetuity. Still, I bet my favorite hat that once you consider the externalities and conversion losses the transmission lines are a clear winner. The electrical grid really only causes fires when its neglected, whereas gas infrastructure leaks constantly.
it’s mostly material cost, it’s described in more detail in the paper. it has nothing to do with economies of scale because we’re already installing massive amounts of cables today. there is a connection to the grid level (high-power lines are cheaper than low-powered ones) though.
Still, I bet my favorite hat that once you consider the externalities and conversion losses the transmission lines are a clear winner. The electrical grid really only causes fires when its neglected, whereas gas infrastructure leaks constantly.
nah electrical lines have significant losses. iirc from memory, 500 miles transmission over cables, you lose like 30% of your energy. gas leaks but not that much.
Where did you get the 30%-Figure from?! HVAC-transmission at “only” 380 KV is at about 1% loss, HVDC is even lower than that.
H2 needs to be produced with electrolyses, you lose 30% of your energy with that alone.
it’s 12.9% (i think over 1000 miles)
source is the paper linked above
Those transmission losses don’t have immediate health and environmental costs, though, and even discounting those there’ll be conversion losses on both ends if what we want to get out of it is usable electricity from renewables. Dont take my skepticism for poohpoohing btw, this kind of counterintuitive thinking is one of the more fascinating things about economics. Or maybe I just like to argue :P
I’ll look up the paper, this is an interesting topic.
Doesn’t have ammonia in there?
DC? As in direct current? Isn’t it well known that that’s a terrible way to transmit electricity long distances? Where is AC?
That used to be the case, largely because we used to be really bad at converting AC to DC (and vice versa) so would incur a ton of efficiency loss at the conversion step.
But for the actual on the wire transmission part, high voltage DC is inherently more efficient at long distances because you don’t get drift between the voltage and current phase (which reduces its effectiveness).
These days though we are far better at converting DC to AC (and vice versa) so high voltage DC systems are overall more efficient (plus let you connect distribution systems without synchronizing them, or connect ones that operate on different frequencies like 50Hz vs 60Hz).
Their downside is that conversion equipment is still more complicated and slightly more prone to failure then AC systems.
TIL
High Voltage DC is commonly used for long distance submarine transmission and is increasingly used overland as well. China is using HVDC to transmit power from remote/desert solar panel fields to cities. HVDC has lower costs and lower losses compared to equivalent AC transmission.
Hey now, we cant have electricity looking good.
You’re not factoring in the cost of the hydrogen production, only the efficiency. Furthermore - you need to transport electricity almost everywhere anyway. And transporting electricity is way safer that hydrogen.
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electrolyseurs can be built incredibly cheap. they’re not typically today because of lack of economies of scale.
also do you have sources about the safety thing? because cables cause wildfires in california constantly
Not negating your core point about the economics, but the cable thing in California is mostly due to lack of maintenance…
For example the camp fire started because of a hook that wore though and failed. The hook was almost 95+ years old. A second hook was found nearby in a similar state. This same company also blew up a city block in 2010 killing 8 people, due to a natural gas leak. I can only imagine what theyd do with a hydrogen pipeline.
Go to bed big oil
huh i never argued for big oil at all.
It just looks like it to a layman because the cost for oil is teeny tiny and the cost for electric is absurdly high.
that’s only the cost for transport though, you have to consider all costs
what’s not included, for example, is the cost of giving the money to the dictators that control the area where oil is ectracted. IMHO, giving $1 to a dictator is significantly worse than giving $1 to any other person
Buuut… Why would you transport wind+solar 300 miles? A couple of miles, under 100 or so, sure, but why more than that?
Implementing long-distance high-voltage transmission lines is a common counterargument against the inherent fragile and unpredictable nature of variable renewable energy systems.
It’s fairly frequent (several times per decade) to have high/low pressure systems with a radius of 100’s of km, at which point a variable renewable system (wind+solar) can reach an output below <1% of installed capacity (when combined with the winter season) for extended (hours to several days) periods of time.
At that point, there is the choice of grid-scale long term energy storage up to a magnitude of TWh’s (potentially seasonal), long-distance transmission (up to 1000’s of km) or ensuring that other energy production systems exist that can pick up the slack (requiring redundant capacity, which is inefficient).
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It’s like they are assuming you are converting the solar energy to oil, then transporting it …
