TechnicalNote
LONGi Solar Technology (U.S.) Inc
Document No.: -HOU-T-01-GDate: 14 September 2021
Contents
1INTRODUCTION. 1.1 Background.2SCENARIOS3PROCESS. 3.1 Design of the scenarios.24RESULTS. 4.1 Details of the results.. 35SUMMARY.6REFERENCES.
Appendices
APPENDIX A - SCENARIO LAYOUTS
INTRODUCTION
LONGi Solar Technology (U.S.) Inc (LONGI* or the °Customer) has engaged DNV Energy USA Inc. (DNV) to provide balance of system cost parison servioes for three different modules and three separate layout configurations (LONGIBOS* or the *Project′). These scenarios were studied for hypothetical projects in Texas United States.
1.1 Background
Large format modules are a newer module technology currently being developed by module manufacturers includingLONGi. These modules are larger than standard 72 or 144 cell modules and also have different electrical characteristics.Due to these differences the standard assumptions for how to optimally design a PV array may not hold true. Numerousa project. DNV took these differences into account and ran multiple scenarios to find the cost differences between three design factors are affected by the change to large format modules which also affects the overall balance of system costs fordifferent large fomat modules chosen by LONGi along with three different racking options.
2 SCENARIOS
Table 2-1 describes the modules that were used for the cost parison analysis.
Table 2-1 Modules studied
Module Power (W) Voc (S) Isc (A) Length Width Thickness Area (m²) Weight (kg)Type (mm) (uw) (mm)182-72c 37.7 49.5 13.85 2256 2384 1133 1096 2.556048 32.3 32.6210-60c 210-55c 545 595 41.5 18.36 18.3 2172 1303 2.830116 2.612864 35.3
The following scenarios were studied:
m snoel a (dn) uoo jod u uu anpo auo im wss a sxes : oog designed: one for each module type.puisp aam snoe om (d) uoo juod u uu snpw om ym wass uo pex osusing the 182-72c and 210-60c modules.Scenario 3: A fixed tit racking system with four modules high in landscape orientation (4L) Two layouts weredesigned using the 182-72c and 210-55c modules
3 PROCESS
Costs for various aspects of the project were calculated based on industry research equipment manufacturer quotes andDNV experience. DNV used an approximately 3.7 MWdc power block as a basis forits calculations designing multiple
ressuseeeed seppunounaup semnoe eusoeuesnpopueuuo snoe to calculate the balance of system costs requested by LONGi. All costs are calculated in 2021 United States Dollars.
Wood Mackenzie is an industry research pany that aggregates data from hundreds of solar projects throughout theUnited States and the world to e up with typical costs for specific project parameters. These costs can be fitered bystate project size and equipment type to accurately refiect the costs of a particular project design. DNV relled on thesefigures [1] to find costs for particular project parameters and supplemented this information with quotes from equipment manufacturers to e up with accurate final costs.
3.1Designofthescenarios
DNV designed the scenario layouts based on a relativelyflat rectangular piece of land. The folowing sections descrbe other factors considered.
3.1.1Ground cover ratio
pue sexe useod o odde qpinom eu suss pexg pue n o gen punouf au peuujap Spain. The spacing of the fixed tit rows ensured no interrow shading between the hours of 9 am and 3 pm throughout theyear. As module dimensions vary between the studied modules different row spacings are used for each scenario. DNV didnot optimize the tracker layouts for energy production as the primary goal of this analysis is a parison between module types and their associated balance of system. Row spacing is based purely on what would be reasonable for the area.
3.1.2Racking material
d ods u duu ssg ujo e su u spou Therefore DNV has not caloulated the tonnage of material perrack and has instead focused on the total number of piles based on DNV's experience for each racking type. Further fixed tit racking designs can vary greatly in how the supportstructures are designed with some utilizing multiple smaller supports as opposed to one larger one. DNV has assumed thelarger support option for this analysis.
3.1.3Racking structure
The length and number of racks was chosen so that the layout of the site was rectangular shaped with the optimal shapesuq sus oummo eus eu m sus ee s psuo ose m suuusenbs ue between rows.
3.1.4DC biner boxes
au1 fum unewou buns jo unowe eu ezwuu o Aeue eun noy6nou Aeobajeas paoed auam saxoq auqwoo 0 number of strings per biner box was determined based on typical biner box ampacity ratings the project layout andnumber of strings per rack.
3.1.5Module stringing strategy
For modules in portrait orientation a skip stringing design was used tominimize the length of dchomeruns to the cobinerboxes. When modules are laid out in landscape orientation module leads are not long enough to allow skip stringing sostandard stringing methods were used resulting in longer module dc homeruns lengths. The number of modules per stringwas determined based on the maximum voltage of the modules and inverter and for constructability.
3.1.6 Inverter
Inverters were placed withinthe arrays as is typicallyseen inutity scale projects in the industry. Dpending on the array orientation access roads may bisect a given inverter’'s associated modules or a small segment of the array may be carvedout for the inverters. A twenty-foot-wide access road was assumed. The model of the inverter chosen for these designs iscapable of accepting the various dc capacities in each scenario.
3.1.7 Conductor sizing
ueug sse o doup efejon abeuane euf jull % ueug ssel of doup ebejo unwjxew eun jung o uesoup euem sezis aoponpuo1.5% and meet necessary ampacity requirements. As the 210 modules have higher currents than the 182 module a largerJeenu eu o peno pue puno6apun peunq uau pue sexoq Jeuqwoo op o peno eq o peunsse uam suoonpuo 0 dc string conductor size was used for these conductors to keep the dc losses relatively similar to those of the 182 module.location.
4 RESULTS
The tables below list the total equipment necessary for each 3.7 MWdc block design in Texas along with their associated cost per watt.
Table 4-1 Scenario 1equipment totals and costs
ParameterModule type Scenario 1:1PTracker 182-72c 210-55c 210-60cArray design (32 modules perSystem Design Jad susxusJd Busxus sus xus (27 modules per (35 modules perper rack) x 84 racks rack )x 98 racks rack) x 98 racksDC capacity(MW) 3.67416 3.7387 3.73184Piles per rack 12 10 11Plile spacing (m) 8.1 8.1 8.1Mounting system Total number of piles 1008 086 1078Racking Cost (±/W) 7.27 7.50 7.50Piles (/W) 2.35 2.29 2.52PV string cable 2 way length (m) 21 302 14 329 14 850PV string cable (#10 AWG Cu PV wire) 0.15Cable and ($0.86/m) (/W)biner box PV string cable(#8 AWG Cu PV wire) 0.15 0.13(z/W) ($1.26/m)
