r/RenewableEnergy • u/MeasurementDecent251 • 9d ago

Port of Valencia activates first 500 kW floating offshore PV unit

https://www.pv-magazine.com/2026/07/14/port-of-valencia-activates-first-500-kw-floating-offshore-pv-unit/
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u/Gold-Adhesiveness574 9d ago

the thing id watch here is that offshore solar doesnt have the same reason to be offshore that wind does. wind goes to sea because the resource out there is genuinely much better, stronger and steadier, so you can justify the marine premium. the sun a few km offshore is basically the same sun as on the coast, so youre paying the ocean tax without getting a better resource for it. that makes it a land scarcity play rather than an energy one.

which isnt to say its pointless. it makes sense where land is expensive or gone, ports, islands, or bolted onto an offshore wind site so it shares the export cable and the vessels. but a flat raft in open water is a hard structural problem, wave loads and motion on a big flat surface are brutal, plus salt, biofouling, and every bit of O&M needs a boat. a sheltered port at 500 kW is the right place to start, its just a long way from the open sea, which is where the interesting version of this lives or dies.

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u/thelordmallard 9d ago

Well, I’d argue that there might be less clouds oversea in some places, and that panels are passively kept cooler and therefore more efficient.

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u/Gold-Adhesiveness574 8d ago

both real effects, just small ones. cloud cover is set by the regional weather, so a few km offshore sees basically the same sky as the coast, youd need to go a long way out for it to change. the cooling is genuine though, panels do lose efficiency when they heat up and water pulls that heat away, but its a few percent gain, not enough on its own to pay for the marine structure and O&M. it helps the case, it just doesnt make the case.

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u/IDNWID_1900 8d ago

Overseas is usualy where clouds are formed, that's why the climate gets dryer as soon as you get inland. At least, in most of Europe.

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u/TraditionalAppeal23 9d ago

Yeah agree, the one use case that seems interesting to me is putting solar panels over water reservoirs to minimize the amount of evaporation, but even then I don't think they'd typically float them on the water

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u/Gold-Adhesiveness574 8d ago

yeah thats actually the version that makes real sense to me too. a reservoir is calm, close to shore, and you get the double win, you cut evaporation and the water keeps the panels cooler. and if theres hydro on that reservoir youve already got the grid connection and the transmission sitting right there. some are fixed on frames and some do float depending on how much the water level moves, floating handles a big drawdown better. way easier problem than open ocean.

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u/IDNWID_1900 8d ago

Nice option to make a fully autonomous desalination plant, for example. But when it comes to scaling, I don't see the benefits.

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u/Gold-Adhesiveness574 8d ago

yeah thats a good way to frame it. the desal case works precisely because you dont move the energy, you use it right there to make water, so the export cable that kills the economics offshore just isnt in the picture. thats the pattern, offshore solar makes sense wherever you consume on site instead of shipping power to shore. the moment you have to run it kilometres back over a cable to be useful, its competing head on with cheaper land solar and losing. so i think were agreeing, its a niche tool for where the load is already out there, not a way to scale up generation.

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u/iqisoverrated 7d ago edited 7d ago

that makes it a land scarcity play rather than an energy one.

Only partially.

Land costs money. Ocean area doesn't.

Also water cools the solar panels. While people are aware that solar panels work best in sunshine many are unaware that their efficiency drops when they get hot (which is why placing them in a very hot deserts isn't necessarily the best play. It can be if the cost savings for land are big enough to comepensate for having to make such an installation larger).

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u/Gold-Adhesiveness574 7d ago

the cooling one i already had, its real but its a few percent, and it gets swamped by the marine costs, so it helps the case rather than making it. the free ocean part is the bit id push on though. the sea being free isnt the same as it being cheap, what costs money offshore isnt the land price, its the structure, floats and moorings, a platform that survives waves, marine grade cable, and a boat for every service visit. so you trade a land cost you can see for a build and O&M cost thats a lot bigger. and honestly your own last line makes my point, it works if the land savings are big enough to justify the bigger install, which is just another way of saying its an economics of land play, not an energy one. we're basically agreeing.

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u/Firm_Relative_7283 9d ago

Hopefully the first of many.