Pushing the Frontiers for Floating Solar Photovoltaics -- The Case for South America

This study proposes a techno-socio-economic framework demonstrating that Floating Solar Photovoltaic (FSPV) systems in South America offer a land-efficient, cost-competitive solution for energy access and water security, with significant potential for co-location with hydropower and AI data centers in countries like Nicaragua, Honduras, and Guyana.

The Gist

Imagine South America as a giant, sun-drenched garden that is running out of space to plant new solar panels. Usually, to build a solar farm, you need to clear acres of land, which can clash with farms, forests, or neighborhoods. But this garden has a secret weapon: it is filled with massive lakes and reservoirs.

This paper argues that instead of fighting for land, we should turn these lakes into solar farms. The authors call this Floating Solar Photovoltaics (FSPV). Think of it as putting a giant, floating raft of solar panels on a lake, rather than paving over a field.

Here is the simple breakdown of what the study found, using everyday analogies:

1. The "Real Estate" Advantage: Water is Cheaper than Land

In many parts of the world, land is expensive and crowded. The paper compares South America to a real estate market where the "waterfront property" is surprisingly the best deal.

• The Claim: When you look at how much electricity can be made per square mile of water, South America is the global champion. It has the highest potential of any continent.
• The Analogy: Imagine you are trying to set up a lemonade stand. In Asia, you have to rent a busy street corner (expensive land). In South America, you can set up your stand on a giant, free raft floating on a calm lake. The sun hits the raft just as hard, but you don't have to pay for the ground underneath it.

2. The "Cooling Effect": The Lake is a Natural Air Conditioner

Solar panels hate getting too hot. When they get hot, they get grumpy and produce less electricity (like a runner slowing down in the heat).

• The Claim: The water underneath the floating panels acts as a natural air conditioner. It keeps the panels cooler than panels sitting on hot ground.
• The Result: Because they stay cool, the floating panels work harder. The study found they produce about 5% to 6% more electricity than the same panels sitting on land in the same weather. It's like the difference between running a race in a cool breeze versus running in a hot, humid room.

3. The Case Studies: Testing the Rafts in Three Countries

The authors didn't just talk about theory; they built digital models of solar farms in three specific places to see how they would perform:

• Nicaragua (Lake Xolotlán & Lake Cocibolca): These are huge lakes near cities. The study showed that putting solar rafts here would generate massive amounts of power, especially during the dry season when the sun is strongest.
• Honduras (El Cajón Dam): This is a hydroelectric dam. The authors propose a "Hybrid" system. Imagine the dam already has wires and towers to send electricity to the city. You can just add the floating solar panels to the water right next to the dam and use the same wires. This saves a ton of money because you don't need to build new roads or power lines.
• Guyana (Lake Capoey cluster): This area is being looked at for a very modern use: powering AI Data Centers. These are giant computer warehouses that need endless electricity and cooling. The paper suggests putting floating solar right next to these centers. The water cools the solar panels, and the solar panels power the computers, creating a self-sustaining "green island" of technology.

4. The Money Talk: Is it Worth It?

Building floating solar costs more upfront than building on land because you need special floating rafts and underwater cables.

• The Catch: It costs about 13% more to build initially.
• The Payoff: Because the panels work better (they are cooler) and you save money on land, the project makes money faster in the long run.
• The "Dam" Bonus: The study found that if you build on a dam (like in Honduras) and use the existing power lines, the cost drops so much that it becomes one of the cheapest ways to make electricity in the world—cheaper than even the land-based solar farms.

5. The "Double Win": Saving Water and Air

• Water: The floating panels act like an umbrella. They shade the water, stopping it from evaporating in the hot sun. In dry regions, this saves a massive amount of fresh water (up to 60% less evaporation).
• Air: By replacing electricity that would have been made by burning oil or gas, these floating farms stop pollution. The study calculated that for every unit of power made at the Honduras dam, they could prevent the release of tons of carbon dioxide and other smog-forming gases.

6. The Hurdles: It's Not All Smooth Sailing

The paper is honest about the challenges. Putting electronics on water is tricky:

• Rough Waters: Big waves and strong winds can stress the floating rafts. They need to be built like ships, not just rafts.
• Nature and People: If a lake is used for fishing or tourism, putting a giant solar raft there might block the fishermen or ruin the view. The paper warns that you can't just drop these rafts anywhere; you have to talk to the local communities and make sure you aren't blocking their livelihoods.

Summary

The paper's main message is simple: South America has a golden opportunity. It has huge lakes, plenty of sun, and a need for clean energy. By turning these lakes into floating solar farms, the region can generate more electricity, save water, and lower costs—especially if they build these farms next to existing dams or data centers. It's a way to use the water we already have to power our future, without taking up any more land.

Technical Summary

Technical Summary: Pushing the Frontiers for Floating Solar Photovoltaics – The Case for South America

Problem Statement
Access to reliable, affordable, and sustainable electricity remains a critical barrier to development in many regions, particularly within marginalized and geographically isolated communities. While solar photovoltaic (PV) technology is a cornerstone of the global energy transition, conventional ground-mounted systems face significant constraints in Latin America and the Caribbean (LAC). These include land-use conflicts with agriculture and urban development, fragmented land ownership, and thermal degradation of modules in tropical climates. Furthermore, many LAC nations rely heavily on hydropower, making their grids vulnerable to climate variability and droughts. Although Floating Solar Photovoltaic (FSPV) systems offer a pathway to utilize underutilized water surfaces, avoid land conflicts, and provide cooling benefits, deployment in South America remains limited compared to Asia. There is a lack of integrated techno-socio-economic frameworks that evaluate FSPV potential specifically within the diverse energy contexts of South American nations, particularly regarding hybrid hydro-FSPV integration and comparative performance against land-based systems.

Methodology
This study develops an integrated techno-socio-economic framework to evaluate FSPV deployment across selected water bodies in Nicaragua, Honduras, and Guyana. The methodology encompasses:

1. Resource Assessment: Identification of representative water bodies (Lake Xolotlán and Lake Cocibolca in Nicaragua; Lake Yojoa and El Cajón Reservoir in Honduras; and the Lake Capoey–Mainstay–Tapakuma cluster in Guyana) based on surface area, accessibility, and grid connectivity.
2. Technical Simulation: Detailed modeling of FSPV systems ranging from 50 MW to 398 MW. The analysis includes electrical system architecture (collector substations, cable configurations, and inverter sizing), performance ratio calculations, and annual energy yield simulations under site-specific climatic conditions.
3. Comparative Analysis: Direct comparison of FSPV performance against equivalent land-based PV (LBPV) systems under identical regional climatic profiles to isolate the impact of water cooling and reduced soiling.
4. Techno-Economic Evaluation: Calculation of Levelized Cost of Energy (LCOE), Net Present Value (NPV), Internal Rate of Return (IRR), and payback periods. The study distinguishes between standalone FSPV installations and hybrid hydro-FSPV configurations that leverage existing hydropower infrastructure.
5. Special Use Case Analysis: Examination of FSPV colocation with AI data centers (Guyana) and hydro reservoirs (Honduras), including greenhouse gas (GHG) emission displacement calculations.
6. Policy Review: Synthesis of renewable energy policies from Argentina, Brazil, and Chile to derive enabling lessons for the region.

Key Contributions

• Regional Potential Quantification: The study establishes that South America possesses the highest normalized FSPV generation potential globally, estimated at approximately 38.26 TWh per million acres of water surface area, significantly exceeding Asia (18.15 TWh) and Africa (11.59 TWh).
• Integrated Framework: It provides a unified assessment model combining resource availability, technical performance, comparative analysis with LBPV, hydropower integration, and deployment feasibility for the LAC region.
• Performance Benchmarking: Through detailed case studies, the paper quantifies the operational advantages of FSPV, demonstrating higher energy yields and capacity factors compared to land-based systems due to the passive cooling effect of water.
• Economic Viability: The study presents financial models for both standalone and hybrid configurations, highlighting how shared infrastructure in hydro-FSPV systems can drastically reduce capital expenditures (CAPEX).
• Environmental Impact: It quantifies the potential for GHG reduction, specifically estimating emission offsets for CO2, NOx, and SO2 when FSPV displaces fossil-fuel generation in hybrid scenarios.

Results

• Energy Yield and Efficiency: Simulated FSPV systems across the selected sites achieved annual energy yields ranging from 1,950 to 2,140 kWh/kW, with DC capacity factors exceeding 20%.
  • Lake Xolotlán (Nicaragua): A 50 MW system yielded 2,265 kWh/kW with a 25.9% capacity factor.
  • Lake Cocibolca (Nicaragua): A 50 MW system yielded 2,082 kWh/kW with a 23.8% capacity factor.
  • Lake Yojoa (Honduras): A 50 MW system yielded 2,075 kWh/kW with a 23.7% capacity factor.
  • El Cajón Dam (Honduras): A 398 MW system yielded 2,065 kWh/kW with a 23.6% capacity factor.
  • Lake Capoey–Mainstay–Tapakuma (Guyana): A 95 MW system yielded 2,144 kWh/kW with a 24.5% capacity factor.
• Comparative Performance: In all case studies, FSPV systems outperformed equivalent LBPV systems by 5% to 6% in annual AC energy output. This advantage is attributed to reduced module operating temperatures (lowering thermal losses) and decreased soiling losses.
• Economic Metrics:
  • Standalone (Lake Managua, Nicaragua): The 50 MW FSPV system showed an LCOE of $0.0476/kWh, an IRR of 24.1%, and a discounted payback period of 5.1 years. While the CAPEX was 13.3% higher than LBPV ($1,500/kW vs. $1,324/kW), the higher energy yield resulted in a 13.8% higher NPV.
  • Hybrid (El Cajón, Honduras): The 398 MW hydro-colocated system demonstrated a CAPEX reduction of approximately 37% (to $950/kW) due to shared substations and transmission infrastructure. This resulted in a highly competitive LCOE of $0.045/kWh, an IRR of 22.1%, and a discounted payback of 5.6 years.
• Environmental Impact: At the El Cajón site, deploying FSPV to displace 25% of fossil-fuel generation was estimated to reduce emissions by approximately 130.2 tons of CO2, 2.2 tons of NOx, and 2.6 tons of SO2 per MW of displaced generation.
• Special Use Cases:
  • AI Data Centers: The study highlights the potential for DC-coupled FSPV and battery storage systems to provide behind-the-meter power for data centers, addressing grid congestion and offering a renewable energy source in water-rich areas like Guyana.
  • Hydro Integration: Colocation with hydropower reservoirs allows for shared transmission infrastructure and improved grid flexibility, conserving water during high solar generation periods.

Significance and Claims
The paper claims that FSPV represents a scalable and technically viable solution to expand clean energy access in South America, particularly for marginalized communities and energy-poor regions. By utilizing existing water bodies, FSPV circumvents land-use conflicts and leverages the cooling effect of water to enhance system efficiency in tropical climates. The study emphasizes that hybrid hydro-FSPV configurations offer a distinct economic advantage by utilizing existing hydropower infrastructure, thereby lowering LCOE and accelerating deployment. Furthermore, the proposed framework serves as a blueprint for policymakers and investors to accelerate FSPV adoption, strengthen the water-energy nexus, and support the transition toward low-carbon energy systems in alignment with Sustainable Development Goal 7 (SDG7). The authors assert that while challenges regarding material degradation, ecological impacts, and social acceptance exist, the techno-economic benefits provide a strong case for prioritizing FSPV in the region's energy strategy.