Crunching the numbers on floating solar - Why Use Cleantech ...

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Crunching the numbers on floating solar - Why Use Cleantech ...
Design and Build Technical Briefing

Crunching the numbers
on floating solar
       Floating PV | A major new study
       published by the World Bank has
       underlined the scale of the opportunity
       represented by floating solar systems,
       but highlighted issues of cost,
       bankability and regulation still
       facing this emerging branch
       of the solar industry. Sara
       Verbruggen reports on
       the first serious piece of
       heavyweight analysis
       of the prospects for
       floating solar

                                                                                                                                                               Credit: Lightsource BP
F
      loating solar has global potential, with   estimate puts floating solar’s overall global   Floating solar      Therefore, this annual figure may not
      cumulative installations exceeding         potential, based on available man-made          capacity now        materialise immediately in 2018 or 2019,
                                                                                                 exceeds 1GW
      1GW today, according to an upcoming        water surfaces, in excess of 400GW. Since                           but is likely thereafter.”
                                                                                                 worldwide, but
floating solar market report, ‘Where Sun         the first floating PV system was built in       has significantly
Meets Water’, written by the Solar Energy        2007 in Aichi, Japan, the market has grown      greater poten-      Costs and project structuring
Research Institute of Singapore (SERIS) at       with projects increasing in size and more       tial if issues      Calculated on a pre-tax basis, the levelised
                                                                                                 around cost and
the National University of Singapore and         countries installing these types of renew-                          cost of electricity (LCOE) for a generic
                                                                                                 bankability can
published by the World Bank and the Inter-       able energy plants.                             be surmounted       50MW floating PV system does not differ
national Finance Corporation.                       Around 500MW was installed in 2017                               significantly from that of a ground-mounted
   That said, investment costs are about         and 2018, much of it in China by making                             system.
US$0.10 per watt higher for floating             use of flooded mine sites. Many floating                               The higher initial capital expenditures
solar projects, compared with equivalent         solar projects are being developed or                               of the floating system are balanced by a
ground-mounted plants, providing oppor-          under feasibility studies in many different                         higher expected energy yield, from the
tunities for collaboration between the           parts of the world.                                                 cooling effects of the close proximity of
solar industry and other sectors in order to        SERIS’ senior financial advisor Celine                           cold water. This is conservatively estimated
bring down costs and deliver large-scale         Paton says: “If they all materialise, then                          at 5%, but potentially could be as high as
projects.                                        yes we could see such annual growth of                              10-15% in hot climates.
                                                 400-500MW taking place. However, the
Demand outlook                                   development and realisation of these                                Capital expenditure (capex)
According to the report,, a summary of           projects also depends on many factors,                              The main difference in investment costs
which was published in early November            which are not always controlled by the                              when comparing floating PV with a
as the first in a series planned by the          owners/developers: politics, environmen-                            ground-mounted PV plant of similar size
World Bank and SERIS, a conservative             tal aspects, but also appetite from banks.                          is in the floating structure and the related

46 |   December 2018 | www.pv-tech.org
Crunching the numbers on floating solar - Why Use Cleantech ...
Technical Briefing Design and Build

                                                   Floating PV                                                                                                        Ground-Mounted PV

                                      19%                                                                                                                      21%
                                                                               34%                   Modules                                                                                        40%
                                                                                                     Inverters
                                                                                                     Mounting System
                                                                                                     BOS
                            18%                                                                      Design, Construction, T&C                        13%
Credit World Bank/SERIS

                                                                           8%
                                                                                                                                                                     16%
                                                   21%                                                                                                                                      10%

                          Source: Authors’ compilation based on 2018 data received from industry. Notes: BOS = balance of system, T&C = testing and commissioning.

                          Figure 1: Floating versus ground-mounted 50MW PV investment cost breakdown (numbers indicative only)

  anchoring and mooring system. These                                                                    numbers on the main average cost per                        A breakdown of the main capex cost
  are highly site-specific, according to the                                                             component for a hypothetical 50MW float-                components assumed for a hypothetical
  report’s authors. At this early stage in the                                                           ing PV system on a freshwater reservoir,                50MW solar PV installation, comparing
  market’s development, lack of experience                                                               based inland. In addition, the theoretical              floating to ground-mounted systems, both
  as well as available data makes it very                                                                site presents no particular complexity. For             of which are fixed tilt, at the same location
  difficult to provide an “average” cost figure                                                          instance, the maximum depth level is 10m                is shown in Figure 1.
  with confidence.                                                                                       and there is minimal water level variation.                 Standard module and inverter costs are
     Cables, a balance of plant (BoP) element                                                               The cost component assumptions used                  assumed identical for both technologies.
  and cost for all types of PV installations,                                                            in the report’s chapter on cost analysis are            Mounting system, including floating struc-
  differ for floating solar projects. Using                                                              based on SERIS’ experience, investigations              ture, anchoring and mooring for floating
  direct current (DC) – in some cases                                                                    and guidance from solar PV equipment                    PV and BoP costs are significantly higher
  submarine – electric cables with additional                                                            suppliers, engineering, procurement and                 for floating solar projects as opposed to
  insulation and shielding properties to                                                                 construction contractors and developers.                ground-mounted.
  protect against moisture degradation,                                                                     The authors stress the figures represent                 On a per watt-peak basis, industry
  potentially adds a premium to the capex                                                                estimations and need to be adjusted once                experience has shown that floating PV
  of a floating solar plant compared with a                                                              the design and location of a specific float-            capital expenditure to date tends to remain
  ground-mounted PV system.                                                                              ing PV project is determined and as more                US$0.10 higher than ground-mounted PV
     In capex cost modelling, the report’s                                                               cost figures become available from the                  projects under similar conditions.
  authors have tried to make reasonable                                                                  completion of more and more large-scale                     Improved economies of scale and
  assumptions in terms of crunching the                                                                  floating PV systems across the world.                   competition between vendors will begin to

                                                                          UK—0.2 MW Sheeplands (2014)                                     1.14
                                                                     Japan—2 MW Shiroishi Saga (2015)                                                                                       3.12
                                                                    Portugal—0.2 MW EDP Hydro (2016)                                                                    2.31
                                                                  UK—6.3 MW Queen Elizabeth II (2016)                                       1.22
                                                                       China—20 MW Anhui Xinyi (2016)                                              1.48
                                                                        Japan—2.4 MW Noma Ike (2017)                                                                                  2.93
                                                                  China—40 MW Anhui Sungrow (2017)                                        1.13
                                                                             India—0.5 MW Kerala (2017)                                                                              2.84
                                                                   Japan—1.5 MW Mita Kannabe (2017)                                                                                   2.93
                                                                Japan—13.7 MW Yamakura Dam (2018)                                   0.97
                                                                    India—2 MW Andhra Pradesh (2018)                               0.92
                                                                   China—150 MW Three Gorges (2018)                                  0.99
                                                                                                                                                                                                           Credit World Bank/SERIS

                          India—5 MW West Bengal Auction Lowest Price (2018) India—5 MW West                                      0.83
                                                                         Bengal Auction Avg Price (2018)                                  1.14
                                                                                                               0.0          0.5           1.0          1.5        2.0          2.5           3.0   3.5
                                                                                                                                    0.8          1.2         USD/Wp

 Figure 2. Investment costs of floating PV in 2014–2018 (realised and auction results)

                                                                                                                                                                www.pv-tech.org | December 2018 | 47
Crunching the numbers on floating solar - Why Use Cleantech ...
ADVERTORIAL

 Floating solar industry turns to
 Seaflex for its mooring expertise
 Many investors, project managers, engineers, and product                example, different environmental conditions like water levels and
 manufacturers are concerned with the longevity of individual            wind from two identical 2.5 MW facilities can have very different
 components of floating PV systems. The LCOE generally                   designs and costs associated with the mooring. Another factor
 revolves around a lifespan of 20-25 years for such floating PV          can be the proximity of the solar panels and floats to the shores
 projects. How does Seaflex tackle the challenge of longevity            of the water source. A system located in the middle of a body
 and make ownership cost effective?                                      of water is moored differently than one where all four sides are
   Our approach to a 20-year-plus longevity for our mooring              close to the shores.
 systems comes from several factors. First being that we have a            Factors such as these are why we caution designers and
 20-year warranty on our products and mooring solutions. We can          engineers not to guess about the mooring solution based
 offer this because we have over 30 years’ experience designing          on sizes or designs of other seemingly similar floating solar
 and building marinas using the Seaflex mooring systems. We              applications.
 currently have Seaflex in marinas that are over 30 years old, so
 we know from real-life experience that our products, materials          Why is using Seaflex versus other mooring technologies
 and designs last a long time.                                           beneficial for floating solar applications?
   We have adapted our range of Seaflex products and mooring             The use of metal cable and chain in mooring floating solar
 designs to be utilised in the floating solar segment. We have           projects is one type of solution that comes with many drawbacks
 numerous different mooring designs and products that can                and potential devastating failures. We have seen such real-life
 handle a wide variety of environmental factors such as water            failures and therefore can comment on the design and material
 levels from zero meters to hundreds of meters deep. We also             inadequacies.
 have existing floating solar projects that have survived typhoons         Seaflex offers an elastic solution that unlike metal cable and
 without failure. So, we can say from real-world experience that         chain provides a dampening effect that neutralises shocks
 Seaflex, installed on floating solar applications, can also withstand   (or peak load effect) to both the floats and solar panels from
 extreme wind conditions as well. Additionally, our mooring              wave and wind forces. This is beneficial from both a safety and
 products are compatible with every floating solar panel float,          durability standpoint in that the possibility of potential damage
 which allows for seamless integration and helps to increase the         over a 20-year period is minimised, saving material replacement
 lifespan of the floats and solar panels.                                and labour costs. It should also be said that the usage of piles as
   Since Seaflex products only require routine inspections and           a mooring solution has the same risks as cables in that shocks
 do not require maintenance, we provide a much lower cost of             and peak loads are not at all dampened and therefore can also
 ownership over the lifespan of our applications.                        create a total failure in storm conditions.
                                                                           Additionally, Seaflex products utilise very little metal and even
 What should designers and engineers be careful to consider              offer a titanium hybrid option to drastically limit corrosion and
 when looking at mooring solutions for floating solar                    material degradation. Another benefit of our elastic mooring
 applications?                                                           solution is that Seaflex can handle water level variations from very
 One misconception that many designers and engineers have                small to very large (+50 meters!) This would not be possible using
 when considering the mooring aspect of the floating solar               the metal cable, chain or pile solutions.
 application is the correlation between the size (in megawatts)
 of the system and how much in terms of cost and quantity of             If you have questions about this article or other questions
 mooring is needed. Unfortunately, the relationship is not linear        regarding floating solar applications, please do not hesitate to
 and is somewhat complex to describe.                                    contact us at info@seaflex.net
   There are many factors which can change the quantity,                 For information on Seaflex products, services and reference
 composition of materials and design of the mooring system. For          material please visit our website at www.seaflex.net

 48 |   December 2018 | www.pv-tech.org
Crunching the numbers on floating solar - Why Use Cleantech ...
Anchoring innovative                                     KERALA, INDIA
floating applications                                     Adtech Systems Limited

is our passion!
                                                         Shown above is a 0.5 MW floating
                                                         solar park in India, the SEAFLEX
                                                         holding it in place manages their 20+
SEAFLEX is the flexible mooring solution                  meter water level variation.
that has been securing floating applica -
tions world-wide since 1981. The system
can be used regardless of water depth,
                                                      How Seaflex mooring works
while handling large water level variations,
strong currents and storm conditions.                            Floating application          Buoy

We are thrilled to follow the development in the
groundbreaking floating renewable energy sector.
                                                        Seaflex                          Rope
Anchoring such innovative applications couldn’t be                                                    Seaflex
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                                                      tide and wave, taking on and
                                                      dampening the forces
                                                      year after year.
   GEUMJEON, KOREA, Nemoeng Co.
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   110 x 100 m platforms.
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                                                                                        www.seaflex.net
Design and Build Technical Briefing

                                                                                                    Ground-mounted PV                    Floating PV        of floating PV systems under similar condi-
                                                                                                        (fixed tilt)                       (fixed tilt)       tions is estimated to increase by 5% in
                                                                                                                                                            the conservative scenario and 10% in the
                            Electricity produced (first year), GWh                                             75.8                           79.6
                            Increase in performance from ground-mounted fixed tilt                                                             5%            optimistic scenario.
                                                                                                                                                               In the conservative scenario (+5% PR),
Credit: World Bank/SERIS

                            LCOE (U.S. cents/kWh)
                                                                                                                                                            the LCoE of a floating PV system is 8-9%
                            at 7% discount rate (base case)                                                     5.0                           5.6           higher than the LCOE of a ground-mount-
                            at 8% discount rate                                                                 5.2                           5.7           ed PV system. In the optimistic scenario
                            at 10% discount rate                                                                5.4                           6.0           (+10% PR), the floating PV LCOE is only
                                                                                                                                                            3-4% higher than the LCOE of a ground-
                           Source: Authors’ compilation.
                           Note: GWh = gigawatt-hour; kWh = kilowatt-hour; LCOE = levelized cost of electricity; MWp = megawatt-peak; PV = photovoltaic     mounted PV system.
                                                                                                                                                               In time, say the report’s authors, this
                           Comparing the levelised cost of electricity from a 50MWp floating with that from a ground-based PV system
                                                                                                                                                            difference is likely to reduce, become
                                                                                                                                                            zero, or may even reverse with an
                            System size (MWp)              Business model      Ownership                       Financing structure                          increasing installed base and anticipated
                                       ≤5                  Self-generation     Commercial and                  Pure equity and/or corporate financing       cost reductions for floating PV instal-
                                                                               industrial companies            (or “on balance sheet” financing). Owner     lations as volumes go up. The installed
                                                                                                               would typically be an energy-intensive
                                                                                                                                                            capacity today is much smaller in relation
                                                                                                               commercial or industrial company
                                                                                                               with ponds, lakes, or reservoirs on its      to ground-mounted PV systems across
                                                                                                               premises and willing to install a floating   the world.
                                                                                                               solar system for its own use.
                                       >5                  Power sold to the   Independent power               Mix of debt and equity (typically 80:20);    Bankability
                                                           grid                producers and public            on balance sheet or non-recourse             According to the report, from an investor’s
                                                                               utilities                       project finance. The latter is still rare,
                                                                                                                                                            perspective, more traction needs to be
                                                                                                               however, because such project finance
Credit World Bank/SERIS

                                                                                                               structures make sense only for projects      gained in terms of bankability of floating
                                                                                                               of a certain size (generally larger than     solar systems, which will come over time,
                                                                                                               10 MWp). Future large projects will likely   when durability and reliability have been
                                                                                                               have financing structures similar to
                                                                                                                                                            proven in real-world installations.
                                                                                                               the ones used for utility-scale ground-
                                                                                                               mounted PV projects.                            In this early phase of the market, floating
                           Source: Authors’ compilation.                                                                                                    solar PV plants are deemed to have more
                           Financing structure versus size of floating solar system                                                                         risks than conventional land-based instal-
                                                                                                                                                            lations. They include a lack of experience
                                                                                                                                                            with long-term reliability of system compo-
                           drive down float costs, lowering capex.               Levelised cost of energy (LCOE)                                            nents, particularly modules, cables and
                              Module costs are a slightly smaller                Data from across the world shows that                                      inverters, under permanent high-humidity
                           proportion of overall investment costs                floating PV systems have a higher energy                                   conditions. Paton says: “This remains one of
                           for a 50MW floating PV project, at 34%,               yield compared with ground-mounted PV                                      the main barriers at this stage.”
                           versus 40% for a 50MW ground-mounted                  systems under similar conditions.                                             According to the report’s authors, when
                           solar plant.                                             Irradiance level and ambient tempera-                                   banks are considering investing in projects,
                              Design and construction costs and                  tures relating to the climate where a                                      they are looking at the creditworthiness of
                           inverter costs see little variation, though           project is located are an even more sensi-                                 every counterparty. This will stand in the
                           are proportionally slightly less for a float-         tive variable for calculating the energy                                   favour of big, established solar developers
                           ing PV farm than for a ground-mount PV                yield and, therefore, the LCOE of floating                                 and EPC companies. In many cases these
                           installation.                                         solar plants.                                                              types of businesses also have the funds for
                              Together, mounting system, which                      Preliminary results show that in                                        on-balance sheet financing that charac-
                           include floats, and BoP costs are higher as           hotter climates the energy yield gain of                                   terises how projects have tended to be
                           a proportion of capex for a floating solar            a floating PV plant when compared to                                       financed and funded in the initial stages
                           project, compared with a ground-mounted               ground-mounted technology is higher                                        of the conventional, land-based, solar PV
                           one. For floating PV, BoP and mounting                than in temperate climates thanks to the                                   market’s development.
                           system costs account for 39% of total                 cooling effect on PV modules, improving                                       “That said, we are seeing a mix of
                           capex investment, compared with 29% for               their efficiency.                                                          models at this stage, especially when
                           ground-mounted PV.                                       However, the authors advise that more                                   systems are not too large and funded
                              Regionally floating PV capex varies                studies should be done to verify this asser-                               with equity or corporate – balance sheet
                           just as it does for ground-mounted PV,                tion and to more accurately quantify the                                   – financing, or a mix of both, from the
                           market by market. As reflected in Figure              correlation between energy yield gains                                     owner,” Paton says.
                           2, Japan remains a region with relatively             and various climates.                                                         Traditional solar developers with experi-
                           high system prices, while China and                      In the report, representative ‘average’                                 ence of developing large rooftop and
                           India achieve much lower prices, a trend              P50 global horizontal irradiance and                                       ground-mounted PV projects are diversify-
                           reflected in these countries’ ground-                 performance ratio figures for ground-                                      ing into floating PV. Examples include
                           mounted and rooftop solar system prices,              mounted PV have been estimated for each                                    Lightsource BP, Canadian Solar, Sunseap
                           in the context of the global average.                 climate zone. The performance ratio (PR)                                   and Cleantech Solar. Some of them are

                           50 |   December 2018 | www.pv-tech.org
Technical Briefing Design and Build

doing the EPC themselves or are outsourc-                                  Oliver Knight at the World Bank’s           compensation rate adder. A renewable
ing it to other companies.                                             Energy Sector Management Assistance             energy certificate (REC) mechanism has
   According to Paton: “Most of the time                               Programme (ESMAP) division says:                also been implemented in South Korea,
the company providing the float structure                              “Floating solar is more straightforward to      which favours floating solar over ground-
will be involved in overall plant design, EPC                          develop in many cases, since large bodies       mounted plants. In countries in Southeast
and operations and maintenance (O&M)                                   of manmade water tend to be under               Asia, such as Vietnam, floating PV projects
support; thereby ‘training’ the developer to                           public or government ownership, such as         benefit from the same FiT as ground-
gain skills in floating PV. The float supplier                         hydropower dam reservoirs, for example.         mounted PV, which was also the case in
therefore has a key role to play in the                                If you have one owner then the project          Japan, though FiTs have been removed for
development and construction of these                                  is simpler to develop rather than dealing       large projects.
plants.”                                                                                                                   What is needed, say the report’s authors,
   In certain jurisdictions float suppliers                                                                            are more empirical studies to determine
are forming partnerships with developers,         “Floating solar is more straight-                                    the exact advantages of floating PV
such as Ciel & Terre, a French company that                                                                            systems in various climates or how to
has commercialised a floating PV mount-
                                                  forward to develop in many                                           create beneficial hybrid business models,
ing system and is working with developers         cases, since large bodies                                            with hydropower plants, for example.
and EPCs in France, the UK, the US, Colum-                                                                                 “Floating PV is still a new applica-
bia and other markets.                            of manmade water tend to                                             tion and there will be a need to address
   The market has also provided opportu-                                                                               it specifically through regulations and
nities for new developers, which are defin-
                                                  be under public or govern-                                           policies, especially with regards to permit-
ing their business or service as a one-stop       ment ownership. If you have                                          ting, licensing and eventually minimum
shop floating PV solution provider. “This is                                                                           quality standards,” says Paton.
in the case of maritime companies looking         one owner then the project is                                            Knight adds: “There may be a need for
to bring their skills to floating offshore                                                                             enhanced monitoring for a country’s first
solar projects in marine or nearshore
                                                  simpler rather than dealing with                                     few floating solar projects, particularly in
environments, which are more compli-              several”                                                             terms of gathering evidence of the environ-
cated to do than floating solar systems on                                                                             mental impacts of such projects on fish and
reservoirs,” Paton says.                                                                                               other aquatic life. This would be a good
   According to the report, in order to                                with several. In many cases the owners          candidate for concessional or grant financ-
design, build, commission and operate                                  want these assets to be used.”                  ing, for example using climate finance.”
floating solar PV plants that are bankable                                Both Paton and Knight agree that                 As the market is at an early stage the
and are able to produce competitive, clean                             subsidy regimes for floating solar – though     authors are cautious in their expectations.
electricity, collaboration is needed that                              they do exist in some markets – are not         However, in future, in some locations and
aims to bring together relevant skillsets                              usually necessary, as solar costs have          depending on the specifics of projects,
from a range of companies.                                             already come down significantly.                such as design complexity and floating
   The adapted supply chain needed to                                     Countries with subsidies for the             structure, the LCOE of floating PV instal-
deliver floating solar will span develop-                              technology include Taiwan, which has            lations could reduce to below that of
ers and EPCs experienced at developing,                                a specific feed-in tariff (FiT), and the US,    ground-mounted PV, making them the
building and operating large-scale conven-                             where Massachusetts has a location-based        cheapest form of solar generation.           
tional solar plants, float manufacturers,
such as chemicals producers, companies
experienced in designing and developing           Hybrid approach – hydropower and floating solar
floats for maritime applications, providers
                                                  The potential for building solar farms on hydropower water bodies could have unique advantages
of mooring and anchoring equipment and            over other sites. Potentially capex costs could be streamlined as solar installations can piggyback on a
hydropower plant operators.                       hydropower plant’s under-used grid connection.
                                                     Hybrid clean generation plants are being commercialised in all flavours, such as solar+wind,
                                                  solar+wind+storage, around the world. In the case of floating solar PV and hydropower, especially in
Market support
                                                  dry regions, the two resources are highly complementary. Installing solar can reduce over-reliance on
Policy and regulatory framework needs to          hydropower for electricity generation. “Hosting floating solar farms that feed into the same grid connection
be adapted in some markets, the report            means that in summer months solar takes care of demand for electricity that hydropower generation would
adds. “As an example, in certain jurisdic-        usually supply, preserving the water resource during dry seasons and spells,” says the World Bank’s Oliver
                                                  Knight.
tions like in the Netherlands, the owner-
                                                     Some hydropower resources have such large bodies of water that a solar array would only need to cover
ship of an asset, in this case a floating solar   1-2% to double their existing installed power capacity.
system, constructed above an immovable               Some Asian countries are particularly interested in floating solar on hydropower reservoirs, including
site owned by another party, in this case,        Vietnam, which has a lot of dams but limited available land. “Myanmar has initiated a floating solar study
                                                  and there is similar interest in India also,” says Knight.
a reservoir, can complicate how to enforce
                                                     In West Africa, where ESMAP is funding a number of studies on solar, floating PV plants on hydropower
certain lenders’ securities over the assets,”     dams can bring different benefits as in many areas where grids are weak, hydro can firm up solar output,
says Paton.                                       according to Knight.
   On the other hand, floating solar                 Countries with floating solar on hydropower resources projects include Indonesia, with 200MW under
                                                  development, Vietnam with 47.5MW under development, Thailand with a 45MW and 24MW project under
projects can pose fewer development
                                                  development, Brazil and India with large-scale projects in development. Lithuania has a pilot project
headaches, especially during the early            underway. According to SERIS there are likely to be others underway that they are not aware of.
permitting stages.

                                                                                                                      www.pv-tech.org | December 2018 | 51
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