not for nothing, but the reduced growth of algae from a lack of UV exposure also means an increase in pathogens that would otherwise be killed by UV. it doesn’t really matter if the water is being treated downstream, but this idea (cover the water!) was posited as a potential solution to algae issues in irrigation water catchment/recycling where the water was similarly nutrient loaded and prone to blooms, often toxic. and where evaporation losses are costly.
it creates other, different problems in terms of pathogens to overcome the “loss” of UV that have to be dealt with. fortunately the power/energy generation could be applied to operational needs for whatever that infrastructure looks like. so probably a UV water treatment solution downstream at the point(s) of use, assuming its for drinking or irrigation.
fyi: the global average for inland surface water losses from evaporation is 3 meters per year. so, on average, an olympic size pool (50m long x 25m wide x 3m deep) loses its entire volume (almost a million gallons) over a year. or averaging around 2700 gallons a day.
wonder if there’s a wavelength of UV that will kill the pathogens but not feed the algae and you just tap some of the panels for some lights
Was thinking the same thing, UV bulbs under the panels shining into the water on the way. although if it is getting treated down the line maybe it doesn’t matter
it would probably be crazy inefficient to block out the sun then install sun bulbs under the shades. i’m sure we could come out with a deal to block only some of it out.
Maybe we can put a little sun under the sun blocker
not sun bulbs just some LEDs, full spectrum would defeat the purpose of preventing algal growth
The fact that these things don’t get shut down at night makes me feel like the UV from sunlight part is not part of making it safe.
there’s probably environmental changes from having the stuff that UV kills not be killed even if it doesn’t matter for the pre-consumption treatment.
this is the same reason why it makes arid regions more fertile, because it lowers evaporation
Water evaporation tends to be a very small conveyance loss in canals. I’ve found sources saying 0.24% of total inflow, so a 70% reduction still probably doesn’t justify the increased construction cost by itself…
If it doesn’t significantly increase maintenance and repair costs of either the panels or the canal it’s probably still a good idea.
Bifacial panels, which get energy from both sides, would benefit from light reflecting off of the water surface. At least on the surface it seems like this is a pretty ideal situation for those.
Which it probably does? I mean, the whole “put solar panels over highways” shtick had the same main issue.
I think you’re not considering the Chinese perspective.
