Before starting a large-scale solar project | should you consider
Start a large-scale project first must confirm grid access capacity.
Because 1 megawatt usually needs 10,000 square meters of land, must complete consume time 6 to 12 months's grid connection feasibility and environmental impact assessment research before getting land, to avoid built but unable to grid connect's huge amount loss.
Land Use
Measure slope
Site selection early stage's 3D terrain mapping data decides later stage earthwork engineering amount's 60% above's expense budget. The whole photovoltaic plant area's north-south direction's natural ground slope suggests control at 5 degrees to 8 degrees interval, east-west direction's undulation drop must not exceed 10 degrees. If you use a single axis fixed adjustable bracket, when the local ground slope exceeds 15 degrees, to prevent the square array's shadow block, layout spacing needs to be from standard's 6.5 meters pull large to 8.2 meters above, this will let unit hectare's installed capacity density drop 18% to 22%.
l When the terrain slope locates at 10 degrees to 15 degrees between time, per hectare's mechanical leveling fee usually needs an extra increase of 3,500 dollars to 5,200 dollars. At the same time, water soil conservation's grid plant grass slope protection cost will also be according to per square meter 2.5 dollars to 4.0 dollars's rate linearly superimposed.
l The past five years's construction statistics data shows that a slope exceeding 20 degrees's hilly region will cause crawler type pile driver's enter scene in place time extend 45%, single root steel pipe pile's sink pile operation consume time from conventional's 3 minutes to 7.5 minutes, extra produced's machine shift lease fee high reaches every day 1,200 dollars.
l Site inside local low-lying region's area occupy ratio if larger than whole plant area's 12%, in design time must according to 25 years one meet's max 24 hours rainfall amount (usually exceeds 150 millimeters) to configure intercepting ditch, every extend 100 meters's concrete drainage open ditch cost price fluctuates between 4,500 dollars and 6,000 dollars.
Calculate rent
Commercial land use's lease year limit usually requires sign cover whole equipment life cycle's 25 years to 30 years long term contract, and in contract inside anchor annualized inflation rate. The different land block attribute's annual rent difference is extremely big, non-agricultural wasteland's base rent is usually per hectare every year 400 dollars to 800 dollars, while close to 115 kilovolts high voltage power transmission corridor 3 kilometers inside's high quality idle land block, rent premium rate will reach 40% or even 85%.
l In the 1st year to 30th year's cash flow statement, land rent increment clause usually sets as every 5 years upward adjust one time, single time upward adjust amplitude strictly locked at 8% to 12%'s fixed ratio, to hedge CPI every year average 2.5%'s compound growth impact.
l Sign long-term lease agreement before need pay's intention exclusive money standard, generally according to first year rent total amount's 15% to 25% pay, this sum amount is about 1.5 to 3.5 ten thousand dollars not equal, usually requires signing a letter of intent after 14 working days inside wire transfer to third party escrow account.
l Developers need to pay the landlord per hectare 1500 dollars to 2500 dollars's land reclamation deposit. This sum is in the financial statement inside according to a 3% to 4.5% discount rate calculate long-term receivable interest.
Check soil quality
Geological survey report inside's soil physical mechanics index decides photovoltaic bracket base structure's choose, influences occupy total investment amount 7% to 9%'s base construction budget. A standard site usually requires shallow layer soil's bearing capacity characteristic value to reach per square centimeter 1.2 kilograms (kg/cm²) above, when meeting bearing capacity lower than 0.8 kilograms/square centimeter's soft soil or swamp landform time, conventional's micro hole cast-in-place pile must upgrade to cost price more high's spiral steel pile.
l Field pull pile pulling force test if in vertical direction bear load less than 15 kilonewtons (kN) or horizontal direction displacement larger than 10 millimeters, base design pile length must be from standard's 1.5 meters to 2.2 meters to 2.8 meters. This makes the single root bracket's use of steel increase from 12 kilograms to 18 kilograms.
l Soil sample's acid-base degree (pH value) if lower than 5.5 or sulfate content exceeds 2000 milligrams per kilogram, will cause carbon steel galvanized bracket's annual average corrosion rate to exceed 25 micrometers. This time, the hot dip zinc coating thickness must be increased from 65 micrometers to 85 micrometers, correspondingly pushing high bracket procurement cost per watt to 0.015 dollars.
l Ground surface below 1 meter to 3 meters range inside the existing volume exceeds 0.5 cubic meters's isolated stone probability if larger than 5%, adopt mechanical lead hole operation will make single hole's manual and mechanical comprehensive cost price soar to 25 dollars to 40 dollars, overall drive pile construction period will be pulled long 30% to 50%.
Look compliance
Obtain land use permit's administrative approval process contains environmental impact assessment and land use purpose change, whole cycle's consume time usually at 12 months to 18 months around. Site boundary must distance national level nature reserve, first class water source place or wetland buffer zone at least 500 meters to 1000 meters's straight line distance, once mapping coordinate happens deviate cross, will face 100% project veto probability.
l Pay's single item environmental protection assessment report compilation fee usually locates between 4.5 ten thousand dollars and 8.5 ten thousand dollars. If the site is inside a protected animal or plant habitat, it needs extra payment of 5 ten thousand dollars to 12 ten thousand dollars's environment compensation money or biological migration budget.
l Land attribute change if involves taking pasture land and turning it into industrial use, the local government will according to per hectare 1.5 ten thousand dollars to 3 ten thousand dollars's standard one-time levy land use purpose conversion tax, and every year pay's fixed asset property tax tax rate will from agricultural standard's 0.5% jump rise to 1.8% to 2.5% between.
l The plan permit stage requires the project boundary must equip a height of 2.4 meters to 3.0 meters' physical isolate fence, every 1000 meters' galvanized iron wire mesh isolate belt, and a superimpose anti-infrared intrusion detect system's comprehensive build cost at 2.2 ten thousand dollars to 3.5 ten thousand dollars interval.
Build open road
Large scale power transformers, inverter step-up integrated machines, etc., heavy type equipment's single body weight generally between 25 tons and 40 tons, this towards lead to plant area's external connect road and internal inspection road's bearing capacity proposes rigid index. The distance from the main line highway exceeds five kilometers, and the newly built entrance scene roads' budget will become a heavy asset expense.
l External enter scene road's effective road surface width must reach 6.5 meters above, curve inside's turning radius needs maintain at 15 meters to 18 meters above, to satisfy length reaches 17.5 meters's heavy type flatbed transport vehicle full load 40 tons cargo's two-way traffic requirement.
l Field inside crushed stone inspection main road's pave thickness needs to reach 25 centimeters to 35 centimeters, compaction degree must reach 93% industry standard, every pave 1 kilometer's internal two-lane road needs sand stone aggregate procurement and construction cost total about 4 ten thousand dollars to 6.5 ten thousand dollars.
l In order to cope with annual precipitation amounts exceeding 800 millimeters, the region's rainy season muddy condition, the road base bottom needs to pave tensile strength larger than 50 kilonewtons/meter (kN/m)'s polyester glass fiber geogrid, this item craft will extra increase per square meter 1.8 dollars to 2.5 dollars's civil build material fee.
Grid Access
Measure distance
Pave 115 kilovolts single circuit overhead line, every kilometer's aluminum core cross-linked polyethylene (XLPE) insulated cable cost price at 45 ten thousand dollars around. Length breaks through 15 kilometers, impedance heat generation causes power dispersion degree to double increase, whole 25-year cycle inside's power generation amount loss present value's average number will reach 210 ten thousand dollars. According to the past 100 large-scale facilities' statistical regression analysis, line length every increase 1 kilometer, the overall financial internal rate of return (IRR) will then produce a drop of 0.15% shock fluctuate.
Cross navigable river or high-pressure natural gas pipeline directional drill hole crossing construction, single-time operation usually will produce 18.5 thousand dollars's special approval and construction fee. Soil's long-term thermal resistivity is higher than 1.2 (K·m/W), direct buried cable's trench backfill must adopt thermal conductivity larger than 1.5 (W/(m·K))'s special fluidal solidified soil.
Measure parameter | Statistical distribution | Quantify index | Error range |
Directional drill hole crossing fee | Single time operation median value | 185,000 dollars | ±15,000 dollars |
Solidified soil backfill material | Thermal conductivity lowest value | 1.6 W/(m·K) | +0.2 W/(m·K) |
Direct buried cable trench build install fee | Cost standard deviation | 55 dollars/meter | ±5.5 dollars/meter |
Geological exploration accuracy degree | Survey precision | 98.5% | ±1.5% |
Line up long queue
Take grid connection review material hand over to dispatch authority after, enter power flow calculation and system impact model queue's consume time highest value already climbed up to 38 months. Pay review deposit's rate according to per megawatt 3,500 dollars calculate, if due to fund break midway quit queue, deposit confiscate's probability high reaches 85%, this part sunk cost's dispersion degree extremely high.
Dynamic electromechanical transient simulation shows that adding a newly added 100 megawatts load will cause regional node voltage over limit rate to exceed 95th percentile. Power station developers need to bear about 550 ten thousand dollars's public line expansion sharing fee. High reaches 68% photovoltaic plant once faces per kilowatt (kW) exceeds 200 dollars's step up station transform bill, investment return model then will bankrupt, development right will be forced in secondary market discount 30% conduct transfer.
Buy transformer
Plant inside's 115 kilovolts main step-up oil-immersed type transformer, one 120 megavolt ampere (MVA) specification's heavy-duty hardware, due to raw material metal price presents obvious cyclical rise, delivery time's median value extended to 95 weeks. Weight reaches 110 tons's equipment if delay, will let commercial operation date (COD)'s expected date happen 4 to 8 months's deviation, causing according to month pay's bridge loan interest extra out million dollars above.
Switchyard internal supporting's sulfur hexafluoride (SF6) circuit breaker, short circuit break strength's peak value must withstand 50 kiloamperes (kA)'s extremely high current impact. Optical fiber communication redundancy system's network delay must reach microsecond level's precision, to satisfy grid connection supervisory control and data acquisition system (SCADA)'s compliance, hardware plus network security test fee about occupies total capital expenditure's 0.8%.
Equipment specification | Technical parameter | Test standard | Life and replacement cycle |
Main transformer capacity | 120 MVA | Full load temperature rise <65°C | 25 years to 30 years |
Circuit breaker gas pressure | 0.6 MPa | Leakage rate <0.1%/year | 15 years to 20 years |
Protection device communication | 60 Hz | Sample frequency 4,800 Hz | 10 years to 12 years |
High voltage cable cross section | 630 mm² | Insulation thickness 18 mm | 35 years to 40 years |
Prevent abandoned electricity
When the local power transmission grid's new energy installed density exceeds 35% of the time, every day afternoon 1 o'clock to 3 o'clock's sunshine highest peak stage, photovoltaic arrays will encounter 18% to 32% compulsory limit electricity instructions. Regional spot power trade's locational marginal price (LMP) sample variance will violently expand, per megawatt hour (MWh)'s electricity price has a 5.5% probability of dropping below 0 dollars, appearing a negative 25 dollars's lowest value settlement price.
Limit electricity amount if from financial estimate's 3% soar to actual operation's 14.5%, first year's effective enter grid electricity amount will shrink 13,500 megawatt hours. According to the 0.045 dollars/degree's long-term power purchase agreement mark price convert, annual average cash flow drop amplitude's reduce rate will reach 15%, investment recovery cycle's mathematical expectation value will be pulled long to 8.8 years above.
Add match cell
For suppress AC DC conversion output's power amplitude as well as smooth grid pressure, 85% new projects are rigidly required to install occupy photovoltaic AC side total power 20% to 35% of cell array. Configure one set of 20 megawatts/40 megawatt hours (MW/MWh)'s two hours level lithium iron phosphate (LFP) energy storage cabinet body, early period build install fee will fiercely increase 1150 ten thousand dollars, making total cost price increase value's percentage jump rise 25%.
Cell single body in every year full load cycle charge discharge 320 times's frequency under, front 48 months's capacity degrade rate maintains at 2.8% around. Operate for 96th month, cell's state of health (SOH) lowest value will approach 72% usable capacity red line. The financial account book inside must according to per kilowatt hour 165 dollars's parameter configure, advance calculate and leave enough in the 10th year major overhaul stage's module reset budget.
Project Cost
Calculate build install
One standard 100 megawatts project's civil build plus electrical install labor hours median number is 32 ten thousand hours, labor union requires skilled electrical worker hour salary lowest value is 45 dollars, highest value possible touch 68 dollars.
Pile driver's lease frequency by every day 1500 dollars price, if in rainy season construction causes equipment idle, construction period every delay 15 days, then will produce exceed budget table 1.2% sunk cost expenditure. Bracket system's install tolerance is strictly limited to plus minus 5 millimeters's precision inside, rework rate as long as exceeds total pile number's 1.5%, then will pull low overall profit rate 0.4 percentage points.
In the engineering procurement construction contract's performance guarantee clause, the contractor must provide an irrevocable letter of credit for the total amount of the contract, 10% to 15%. If the commercial operation date is later than the agreed time schedule, liquidated damages will be conducted according to every day per megawatt 250 dollars's rate.
Borrow money interest
Large-scale photovoltaic facility's finance structure usually adopts a 70% senior debt and 30% sponsor equity fund match's pattern. In applying for a 6000 ten thousand dollars's bank non recourse project loan, the benchmark float interest rate is the hook secured overnight financing rate, outside plus upward float 2.25% to 2.75% risk premium, early period's annualized capital cost will reach 7.5% up down. For the next 20 years, the loan cycle inside's add interest fluctuates, the borrower must extra pay principal 0.5% premium buy interest rate swap contract, take float interest rate lock at 5.85% fixed percentile line on.
Loan bank towards project's debt service coverage ratio possesses harsh's bottom line requirement, in light of resource locates at P90 statistical probability (namely 90% of years all can reach's power generation amount)'s worst scenario under, this item debt service coverage ratio's median value absolutely not allowed lower than 1.25.
Offset tax
Apply the 5-year period modified accelerated cost recovery system, the investment party can in the power station grid connection's first year take high reaches 20%'s hardware asset total amount in tax statement inside conduct impairment write-off, second year's write-off ratio even reaches 32%'s peak value.
According to a 21% corporate income tax rate, one set procurement price of 120 ten thousand dollars's main transformer can in front 24 months inside produce near 13 ten thousand dollars's legal tax avoidance amount. In the 25th complete financial year end, all equipment's book residual value will be according to the initial entry account value's 5% conduct liquidate process.
Calculate clear miscellaneous fee
Exclude large bulk hardware trade, project full life cycle's fixed operation expense is a group every year presents 2.5% compound interest growth rate's huge number. All risk insurance policy's premium rate is based on the total asset net value's 0.35% to 0.45% per year, for hail disaster high incidence regions, deductible is usually set by the insurance company compulsory at a single time accident 25 ten thousand dollars's standard limit on.
Project location government collects property tax every year per megawatt, about is 2,500 dollars to 3,800 dollars. This item long reaches 30 years' continuous tax burden occupies late stage total expenditure's 22%. Long-term site rent also will be according to every year's 1.5% to 2.0% increment rate in the 6th year, producing obvious cash flow pressure.
Financial model in first year build account time, must by 3%'s discount rate backward deduce calculate, take per megawatt 2.5 ten thousand dollars to 3.5 ten thousand dollars's facility dismantle and ecology recover reserve fund seal save into third party supervise account.
Calculate profit
Per kilowatt hour electric energy's system marginal levelized cost compressed at 0.028 dollars to 0.035 dollars's narrow range, only when power purchase agreement locked price reaches 0.042 dollars above time, investment portfolio's with leverage internal rate of return then can break through 10.5%'s benchmark line. Annual power generation amount's predict sample standard deviation once expands exceeds 2%, financial net present value has a 15% probability of falling into the negative value interval.
In long reaches 15 years's power purchase agreements, usually, there will be an embedded 1.5% price increment clause every year. Once the actual inflation rate's median value continues for 3 years, and breaks through 3.5%, the power station's fixed electricity price will bring actual purchasing power profit, which will shrink 6.8%.