Question
Asked 19th Feb, 2019
  • Piramal Foundation

What are the negative impacts of putting larg-scale floating solar panels over any water body like river or canal?

There has been an increasing support for floating solar panels over water bodies saying that it reduces the land footprint for such solar projects, decreases surface temperature of the water body thereby reducing the rate of evaporation and utilises a large dynamic area which is more effective way of capturing the solar radiation.
I am trying to find out and understand the negative side of such floating solar panel projects (if there are any).

Most recent answer

17th Jun, 2021
Chaowanan Jamroen
King Mongkut's University of Technology North Bangkok

Popular answers (1)

20th Feb, 2019
Juan Leonardo Espinoza
University of Cuenca
Hi Ankit,
The impacts of floating solar panels on water bodies can be analyzed depending on the type of body...If the water body is artificial (a dam or channel) then some positive (environmental) aspects might arise as the ones you describe.
Some negative environmental impacts can appear when the floating solar panels are installed on natural water bodies such as lakes or rivers. Perhaps the most import impact has to do with the food chain of these ecosystems. Since the solar energy is limited by the panels, the bottom of the chain (producers such as algae) would not be enough to support the next levels (insects, fish, etc.) affecting/changing the whole ecosystem. Other negative impacts (socio-economic) could also affect tourism, fishing, and navigation.
5 Recommendations

All Answers (26)

19th Feb, 2019
Elhadi I. Dekam
University of Tripoli
This is a fantastic idea if one could manage to perfectly install such solar panels over moving river water surface. I may say disadvantages arise when we use dead motion ponds. However, one talks about huge areas for large solar projects which could create an obstruction for commercial activity !
2 Recommendations
19th Feb, 2019
Thomas Reid
Environment and Climate Change Canada
From an aquatic microbial ecology perspective, these would inevitably block out sunlight, a vital source of energy for phototrophic organisms. These organisms are though to potentially provide valuable nutrients (i.e. nitrogen compounds and other hydrocarbons) to their fellow chemotrophs for the purpose of their energy metabolism. A simple shift in the sunlight availability could throw off the metabolic "equlibrium", but who knows at this point if it would have potentially good or bad outcomes.
Additionally, it would also reduce the ability for that body of water to warm up following the winter season, which could potentially induce ecosystem wide changes, depending on how the constituent organisms could deal with such a temperature change.
3 Recommendations
20th Feb, 2019
Marc Swett
Serenity ICS
In some areas, there are invasive species of plants in ponds and lakes. A successful attempt at combatting this has been the placement of floating tarps. This has not been a permanent solution so the scale would be much smaller and would inevitably create challenges from an viability perspective.
2 Recommendations
20th Feb, 2019
Juan Leonardo Espinoza
University of Cuenca
Hi Ankit,
The impacts of floating solar panels on water bodies can be analyzed depending on the type of body...If the water body is artificial (a dam or channel) then some positive (environmental) aspects might arise as the ones you describe.
Some negative environmental impacts can appear when the floating solar panels are installed on natural water bodies such as lakes or rivers. Perhaps the most import impact has to do with the food chain of these ecosystems. Since the solar energy is limited by the panels, the bottom of the chain (producers such as algae) would not be enough to support the next levels (insects, fish, etc.) affecting/changing the whole ecosystem. Other negative impacts (socio-economic) could also affect tourism, fishing, and navigation.
5 Recommendations
We talk about this from time to time and our concerns are freezing the bodies of water. In the northern US we have our great lakes that thousands of square kilometers in surface area and have numerous cities on shore that could use the energy. There are also tens of thousands of smaller lakes, but those are less likely to be used for this approach due to aesthetics.
If you put the arrays towards the middle of the lakes where it's less likely to freeze, then transmission losses as well as the maintenance and infrastructure costs will increase.
To minimize the damage to a lake, you could probably move the array around so the impact is spread out. hopefully 1 dark day won't kill all the algae in one area.
I do like the idea of putting the arrays on top of artificial lakes from dams and reservoirs. But those have run dry from time to time in parts of the U.S.
no easy answers, but appreciate that everyone keeps offering new ideas.
2 Recommendations
23rd Feb, 2019
Abdelhalim abdelnaby Zekry
Ain Shams University
There is no major negative issues except area occupation on the water surface and preventing solar radiation from penetrating to the underlying water. But the water will cool the panels and thereby will be also warmed. As a fluid there will be flow of water form the hotter to the colder regions.
Best wishes
3 Recommendations
26th Feb, 2019
Naseer K. Kasim
Ministry of Electricity/Training and Energy Research Office
Dear Sir,
From my perspective I think there is some difficulties to achieve the required maintenance for the PV modules and the effect of water waving on the stability of the structures as well as the difficulty of getting big tilt angle of the modules, and I agree with all previews answers which submitted by the other researchers which related to the positive impacts of floating the PV modules on the surface of water bodies.
2 Recommendations
27th Feb, 2019
Tony Maine
Queensland University of Technology
I see three issues here (1) commercial activites and navigation (2) cutting off solar radiation from phototropic organisms and (3) heating. (1) is obvious. (3) I don't think is significant as the panels don't ADD any energy to the water, they just intercept it and turn some into electricity. (2) is the interesting case. Phototropic organisms if they use chlorophyll, mainly harvest orange/red and near IR light. So if you used a solar cell that lets this wavelengths through e.g. a DSSC using a suitable dye, you might not disturb the phototrophs very much. But there are two issues - such a solar cell isn't going to be very efficient (Maybe 4%) and some phototrophs don't use only chlorophyll, and harvest green and blue light, and these will be a bit starved of energy.
3 Recommendations
6th Mar, 2019
Bharath Setturu
Indian Institute of Science
11th Mar, 2019
Rajendra Patil
Late Sau Kantabai Bhavarlalji Jain College of Engineering
Agree to Juan Leonardo Espinoza
1 Recommendation
28th Mar, 2019
Charles H. Beach, P.E.
United States Department of Defense - Fort Knox
waves
1 Recommendation
Adding to Charles H. Beach's comments on waves; there would need to be a certain amount of anchoring to accommodate wind driven waves on lakes, etc.
Larger waves such as those found on oceans I think would not be applicable although very large lakes may require more anchoring vs. smaller lakes/ponds. I imagine coast guard organizations would have some information on potential wave sizes per body of water.
If your systems is upstream or downstream from a retention system (dam, etc.) then that would need to be taken into account as well in case of a controlled release or breach due to flooding.
Also, varying water levels for the anchoring. I'm thinking of Lake Mead in Arizona where the water level has fluctuated by 40 feet (12 meters) in the last 5 years.
2 Recommendations
2nd Apr, 2019
Rajendra Patil
Late Sau Kantabai Bhavarlalji Jain College of Engineering
agree with Fred Betz
2 Recommendations
3rd Oct, 2019
FC Prinsloo
University of South Africa
While the creation of a haven for feathered species is a positive impact for floating solar or floatovoltaics, bird droppings and associated efficiency degrading can be a problem if a proper bird deterant means are not installed on the upper ridges of the solar panels.
10th Jan, 2020
Floris Cornelis Boogaard
Hanzehogeschool Groningen
In the Netherlands research is being conducted with underwater drones:
1 Recommendation
6th Apr, 2020
Rutger De Graaf
Blue21
Hi Ankit, we realised a floating solar project in the Netherlands with ecological impacts and water quality impacts as a starting point: https://www.blue21.nl/portfolio/innozowa/
You could also have a look at the work of Rui de Lima who did a lot of work with underwaterdrones to study the impact of floating structures.
best regards,
Rutger
2 Recommendations
25th Aug, 2020
Bruce Kania
BioHaven Inc.
Many prospective floating solar projects will occur on municipal waterways, which are frequently nutrient rich, and correspondingly experience harmful algae blooms. Floating solar systems should concurrently provide water quality enhancement features focused on nutrient sequestration or harvest.
1 Recommendation
14th Sep, 2020
Salah Hamad
University of Omar Al-Mukhtar
Intersted thanks
12th Oct, 2020
Lalit Solanki
National Institute of Technology, Kurukshetra
nice thanks
29th Apr, 2021
Kheng Ka Tan
Independent Researcher
Oxygen depletion at surface water could be an issue without windvinduced mixing, n this may affect the biota. Solar panel will block out sunlight necessary for photosynthesis n the production of oxygen. The potentially this may produce a dead zone morecthan a meter deep.
Artificial mixing of water under cover may be required to bring back an eco equilibrium and lively water.
29th Apr, 2021
Rutger De Graaf
Blue21
Interesting article (in Dutch) about this topic. Researcher did a year of measurements under Floating Solar park https://www.h2owaternetwerk.nl/h2o-actueel/zuurstofgehalte-onder-drijvend-zonnepark-zwolle-blijft-constant
3 Recommendations
Thanks for sharing this article Rutger De Graaf
If you're using the Google Chrome browser, the built in translate feature is ok, and the article is readable.
17th Jun, 2021
Chaowanan Jamroen
King Mongkut's University of Technology North Bangkok

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