Floating Solar Projects for Sri Lanka
Why Floating Solar? Ever Increasing power demand & depletion of fuel Leads to shift our focus to renewable energy sources Wind & Hydro RE sources are specific PV can be installed at any place Major issue of solar PV is requirement of land Floating solar can be installed on any water bodies. Saves water by preventing evporation of water up to 15% evaporation is savd with a 10% of the water body area covered
Advantages of the Floating Solar Water evaporation can be minimized significantly
Cutting down habitable land usage
Increase Solar Cell efficiency through passive cooling
Cutting down Algae and Water Weeds in reservoirs. When there is a large open surface water body with good sunlight exposure and enough micro nutrient in the water, it will be a good place for Algae and Water Weeds to grow. The good thing about these weeds is they provide ample food for aquaculture to feed on. However at places with runoffs from nearby agriculture land, excess of nutrients such as phosphates will cause Algae Bloom where the water will be rapid overgrowth with Algae in a short time. These Algae may die off after a short while causing a high concentration of dead organic matter that starts to decay and consumes dissolved oxygen in water which lead to large number of fish and marine animals dead. Some may even release toxin into the water. The algae population can be controlled and reduced by blocking sun light to the water body. The floating solar farm can offer a substantial blocking of sun lights to the waters.
BEYOND THE FLOATING SOLAR POTENTIALS Floating Solar Farm with Aquaculture Farm. Floating Solar Farm with artificial coral reefs. Floating Solar Farm with seaweed farming. Floating Solar Farm with advance sensory device.
DIVERSIFYING ENERGY PROFILE Both the Hydroelectric and the Photovoltaic will supply the two different demands of the day. At Daytime, the photovoltaic will function as a power source to meet the Day demand, while at night, the dam reservoir that acts like a battery will supply the electricity at night. Photovoltaic can also be optimised to power up close by village and towns while Hydroelectric will responsible for cities and area further away Water saved from evaporation will increase the hydro out put by 15 to 20%
By the use of transparent Solar PV the light reduction under the modules can be reduced and This will facilitate larger surface area than 15% of the water body to be covered by Solar PV.
Disadvantages of floating solar PV mountings/Floating beds are little expensive but could be manufactured locally in Sri Lanka as was done in the first ever floating solar. Excessive water surface coverage may reduce the sunlight which will affect the bottom of the food chain (producers such as algae) would not be enough to support the next levels (insects, fish, etc.) affecting/changing the whole ecosystem. Try and keep a maximum of 15% of the area only covered with Solar PV. Use of transparent Solar modules now available in Sri Lanka can increase the area covered without any bad effects Other negative impacts (socio-economic) could also affect local fishing, and navigation if applicable. But these fishermen could be effectively used for cleaning of the modules regularly increasing employment Maintenance and Servicing of the system is difficult. But could be carried out by the fishermen using clean water from a desalination plant or rain water collected from roofs.
BUILDING A FLOATING SOLAR FARM It must be easily secured. Anything that floats may adrift on water when there is water and air movement. Like ships have anchor to hold themselves in position in waters, these floating solar farms will need to have a specific anchoring mechanism that not only secure themselves in place, but also prevent frequent contact or knocking in between devices to prevent early material failure. It also must endure the raise and drop of water levels over time. It must be modular. Modularity is one of the key concept in building a system with many identical units. It allows easy and fast manufacturing, quicker transportation and easy installation and easy swapping of faulty units.
It must float. The flotation system will need to be able to hold the weight of the panels, frameworks, wiring and other associated inverter modules. The same technology used to build floating barge and ships can be used, not limited to ballast tank systems build from metal, composite, polymer, fiber glass, plastics etc. It must stay afloat for decades. The material choose must withstand years of water damage and sun scorching. A material with long decay lifespan and possibly can be reused for other purpose. It must not corrode or leak chemicals. It is important issue as corroding or materials that leech into the waters may cause environmental hazards and pollution risk to the drinking water or aquaculture it contains.
It must be cost effective. Cost is a sensitive issue in all aspect. If the cost of the material to build a floating solar farm is many magnitude higher than the cost to purchase a land and build a ground based solar farm, the return from the project will be negligible, and will drive cost up for the end user. Optionally it must be green. If you have a whole system that had a purpose towards green energy generation, but using a supporting system and materials that is harmful to the environment, it will be a contradicting approach. Optionally it must have other usage. Like the old saying – kill two birds with one stone. A floating solar farms can have other functions to justify its cost. In some country, the floating solar farms are also seaweed farms and aquaculture farms. With sensor systems, it can act as a water quality control unit and climate study unit like a buoy in the sea. It also can used to mark out dangerous and shallow area of the rivers and lakes and prevent damage to the passing by ship hauls. Some of it will be discussed in the further section below.
The PV Floating Plant Consists PV System Solar Panels installed on floating system. If required tracking solar to be used to increase the output by 25 to 30% Floating System A HDPE floating platform allows installation of the PV system with having walkways for maintenance. Anchoring System To enable the platform adjust to water level fluctuations while maintaining its position in a southward direction. Underwater Cable Transfers generated power from PV system to Land.
Floating Structure
Mooring System or Anchoring System
ď‚´ A mooring system is an permanent structure which keeps the floating panels on same position and prevent them from truing or floating away. ď‚´ Usually mooring system platform can be done by using nylon rope slings.
A sample 1MW Project Details Capacity
1MW
Required Area 62500 Expected Monthly Generation 107,000kWh Solar Panel 400W Quantity
2500 Pcs
Floating Beds
2500 Sets
Solar Inverter
20
DC cables (UL) Set AC Cables (Under water)
Cost Analysis System Output & Savings Over the years Year
Yearly Output (kWh)
CEB Payments (Rs.)
Annual CEB payments (Rs.)
Annual Bank Payment (Rs.)
Accumulated Profit over the Years (Rs.)
CO2 Savings (MT)
Y1
1,280,56
22.00
28,172,318.77
0.00
28,172,318.77
1,383.0
Y2
1,270,32
22.00
27,946,940.22
0.00
56,119,259.00
1,371.9
Y3
1,260,15
22.00
27,723,364.70
0.00
83,842,623.70
1,360.9
Y4
1,250,07
22.00
27,501,577.78
0.00
111,344,201.48
1,350.1
Y5
1,240,07
22.00
27,281,565.16
0.00
138,625,766.64
1,339.3
Y6
1,230,15
22.00
27,063,312.64
0.00
165,689,079.28
1,328.6
Y7
1,220,31
22.00
26,846,806.14
0.00
192,535,885.42
1,317.9
Y8
1,210,55
15.50
18,763,476.87
0.00
211,299,362.29
1,307.4
Y9
1,200,86
15.50
18,613,369.06
0.00
229,912,731.35
1,296.9
Y10
1,191,26
15.50
18,464,462.10
0.00
248,377,193.46
1,286.6
Y11
1,181,73
15.50
18,316,746.41
266,693,939.86
1,276.3
Y12
1,172,27
15.50
18,170,212.44
284,864,152.30
1,266.1
Y13
1,162,89
15.50
18,024,850.74
302,889,003.04
1,255.9
Y14
1,153,59
15.50
17,880,651.93
320,769,654.97
1,245.89
Y15
1,144,36
15.50
17,737,606.72
338,507,261.68
1,235.9
Y16
1,135,20
15.50
17,595,705.86
356,102,967.55
1,226.0
Y17
1,126,13
15.50
17,454,940.22
373,557,907.76
1,216.2
Y18
1,117,12
15.50
17,315,300.69
390,873,208.46
1,206.5
Y19
1,108,18
15.50
17,176,778.29
408,049,986.74
1,196.8
Y20
1,099,31
15.50
17,039,364.06
425,089,350.81
1,187.3
425,089,350.81
0.00
Total
Project Investment Summary System cost
Rs.
Your Contribution
Rs.
120,000,000.00 120,000,000.00
Loan amount
Rs.
0.00
Repayment Months
60
Interest rate
Rs.
11.00%
Monthly Instalment
Rs.
0.00
Return On Investment
Investment
Rs.
120,000,000
Return
Rs.
425,089,351
ROI
-in
Rs.
305,089,351
ROI
-in
%
254%
%
6.53%
20
25,655.49
Annual ROI Investment Period
Conclusion Floating Solar is one of the best options for Sri Lanka Can use all the water bodies including lagoons. Its gives more advantages than the drawbacks Economically feasible Save water and Generate electricity (Most wanted needs to Sri Lanka) Waste Plastics can be recycled to make Pontoon (Floating Beds) use Slon pipes etc as used in the first floating solar PV project in Sri Lanka.