- 01What a Solar BOQ Actually Controls
- 02The 8 Mandatory Sections of a Solar BOQ
- 03The 6 BOQ Mistakes That Cost EPC Firms the Most
- 04The BOQ-to-Procurement Workflow
- 05What a BOQ Pricing Error Actually Costs
- 06Pre-Submission BOQ Checklist
- 07Key Takeaways
- 08Sources and References
A solar project's BOQ — Bill of Quantities — is the document that decides whether your bid wins or bleeds. It converts your engineering design into a measurable price schedule: every panel, cable, structure and earthing rod listed with quantity, unit and specification. Get it right and you win at a margin that survives procurement. Get it wrong and you absorb overruns that can erase months of project profit in a single purchase order.
Yet most EPC firms — especially those scaling from rooftop to ground-mount, or from 1 MW to 10 MW — still prepare BOQs using rough estimates, copied templates, or last project's numbers updated by feel. With EPC margins in India running at 5–9% of contract value, a 3% error across the total BOQ takes roughly 40% of a 7% margin with it. That is not a rounding difference. That is the year.
This guide gives you the complete framework: what every section of a solar BOQ must contain, the line items contractors routinely leave out, the compliance requirements that can invalidate a BOQ in government tenders, and a pre-submission checklist to run before every bid.
“We won a 5 MW DISCOM tender in MP. The BOQ had DC cable calculated by straight-line distance — not actual cable run with routing, elevation and termination allowance. By the time we ordered we were 18% short on cable volume. Emergency procurement at spot prices cost us ₹14 lakh over budget. The margin on that project went from 7% to under 5%.”
— Project Manager, mid-size EPC firm, Central India (2025)
What a Solar BOQ Actually Controls
A Bill of Quantities is a structured document listing every material, component and work item needed to complete an installation, with unit of measurement, quantity and specification. In Indian solar tenders — SECI, NTPC, state DISCOM, PM-KUSUM, PM Surya Ghar — the BOQ is the foundation of competitive bidding. Every contractor prices the same BOQ, which is what makes bids comparable.
But the BOQ does far more than win tenders. It drives your entire procurement cycle. Purchase orders are raised against BOQ line items. Site deliveries are tracked against BOQ quantities. Progress billing is certified against BOQ milestones. Retention and final settlement are computed from it. A weak BOQ does not just lose tenders — it creates procurement chaos across the whole project lifecycle and hands the client the stronger position in every variation discussion.
A well-built solar BOQ is not a spreadsheet. It is an engineering document that determines whether the project makes money or loses it — before a single panel is ordered.
— Headsup B2B Procurement Research, 2026
The 8 Mandatory Sections of a Solar Project BOQ
A complete solar BOQ covers eight distinct categories. Missing any one creates a procurement gap that shows up later as a cost overrun, a delay, or a failed inspection. Section 8 — statutory, insurance and commercial items — is the one most often absent altogether, because it does not look like "material".
Solar PV Modules
The most compliance-sensitive section in the entire BOQ
| Line item | Unit | Key specification | Compliance flag |
|---|---|---|---|
| Solar PV module — state technology (TOPCon / Mono PERC / bifacial) and exact model code | Nos | Wp, Voc, Isc, temperature coefficient, efficiency, bifaciality factor | ALMM List-I, model-level |
| Module type & safety certification | Doc | IEC 61215 design qualification; IEC 61730-1/-2 safety | BIS registration under CRS |
| PID resistance declaration | Doc | IEC TS 62804-1 test reportCorrected | Verify on datasheet, not brochure |
| Salt-mist / ammonia resistance (coastal or agri sites) | Doc | IEC 61701 / IEC 62716Added | Site-dependent |
| Performance warranty documentation | Set | Linear output warranty, ≥80% at year 25; product warranty separately stated | Confirm at order, not at bid |
| ALMM List-II cell-origin declaration + cell traceability | Doc | Cell manufacturer, List-II reference, batch traceability | New requirement post-1 Jun 2026 |
| DCR certificate (where the scheme requires it) | Doc | NISE DCR portal referenceAdded | PM Surya Ghar, KUSUM B & C, CPSU-II |
Do not price modules as one line. Split DCR and non-DCR, because the gap is enormous: JMK Research put domestic non-DCR TOPCon at ₹14.2/Wp in April 2026 against DCR TOPCon at ₹22.3/Wp — and DCR TOPCon then rose 9.4% month-on-month in May.
- ALMM List-II (cells) came into force 1 June 2026. MNRE's O.M. dated 18 July 2026 gave net-metering and open-access projects a limited window: commission on or before 31 December 2026 and List-II does not apply. This is a transition window, not a rollback — there is no blanket extension.
- The 4 August 2026 clarification is the one most BOQs still ignore. Competitively bid projects with bid submission on or before 31 August 2025 stay exempt from List-II; anything bid after that date must comply. For rooftop on government buildings, the exempt bid windows are on/before 9 Dec 2024, or 28 Jul 2025 to 31 Aug 2025.
- PM Surya Ghar residential net metering is exempt from List-II until 31 March 2027, provided the application went through the national portal. List-I still applies.
- Behind-the-meter captive: private consumers are outside both lists. Government and PSU captive projects must use List-I modules now, with List-II cells applying after 31 Dec 2026.
- ALMM List-I remains mandatory for all government, government-assisted, scheme-linked, open-access and net-metering projects — and it is enforced at model level. "Waaree 540 W" is not a specification; the exact model code is.
- Plan for List-III. ALMM for ingots and wafers takes effect 1 June 2028, with the first list published once at least three independent manufacturers with a combined 15 GW are operational. Long-tenor EPC and RESCO contracts signed today will cross that date.
- DCR is a separate test from ALMM. MNRE has confirmed the List-II orders do not change DCR provisions. A module can be List-I listed and still fail DCR.
Inverters and Power Conversion
String, central or micro — and BIS, not just IEC
| Line item | Unit | Key specification | Compliance flag |
|---|---|---|---|
| String / central inverter — state kW rating, phase, DC:AC ratio | Nos | Euro or CEC weighted efficiency, MPPT count and voltage window, THD limit | IEC 62109-1 & -2 |
| BIS registration for the inverter model | Doc | IS 16221 Parts 1 & 2, IS 16169Added | Compulsory Registration Scheme |
| Grid-interface protection settings & compliance report | Doc | Anti-islanding, LVRT/HVRT, frequency ride-throughAdded | CEA Connectivity Standards |
| Inverter mounting structure / room / platform | Nos | Weather-rated enclosure, IP65 minimum, ventilation or forced cooling | Check ambient derating |
| Remote monitoring / SCADA integration | Set | Modbus TCP / SunSpec, data logging interval, remote access provision | Routinely missed in BOQ |
| AC output cable — inverter to ACDB | m | Sized from load and voltage-drop calculation | Measure, do not estimate |
| Auxiliary supply / UPS for SCADA and control | Set | Backup duration as per O&M specAdded | Frequently omitted |
Module Mounting Structures
Fixed tilt or tracker — the design must be site-specific
| Line item | Unit | Key specification | Compliance flag |
|---|---|---|---|
| GI / aluminium mounting structure — state tilt angle and row pitch | MT | Hot-dip galvanised, coating thickness stated in microns (typically 80 µm) | IS 2062 steel, IS 4759 galvanising |
| Foundation bolts / pull bolts / chemical anchors | Set | SS 304/316 or HDG grade, pull-out capacity stated | Commonly understated |
| Mid clamps / end clamps | Nos | Anodised aluminium, matched to the module frame thickness | Must match the specific module |
| Wind load design certificate | Doc | Site wind zone, basic wind speed, terrain category | IS 875 Part 3 |
| Tracker drive, controller and backtracking system (if applicable) | Set | Motor, gearbox, controller, stow strategyAdded | Price O&M of trackers separately |
| Structure earthing bonding jumpers | Nos | Tinned copper braid or GI, table-to-table continuityAdded | Often merged into earthing and lost |
DC-Side Balance of System
The most error-prone section — measure, never estimate
| Line item | Unit | Key specification | Compliance flag |
|---|---|---|---|
| DC solar cable — string wiring | m | 4 / 6 mm² as calculated, 1.5 kV DC rated, UV and ozone resistant, TÜV certifiedCorrected | EN 50618 / IEC 62930 |
| DC main / array cable to combiner and inverter | m | Cross-section from current and voltage-drop calculation, not from precedent | Take from cable schedule |
| MC4 / T4 connectors | Pairs | IP68, 1.5 kV DC, single-brand mating only | IEC 62852 |
| DC combiner box / string monitoring unit | Nos | Fuse per string, DC isolator, SPD, IP65 minimum | Check fuse sizing per string |
| DC cable tray, conduit or underground duct | m | HDPE or perforated GI tray as per layout | Often missing entirely |
| Surge protection device, DC side (Type II) | Nos | Rated for maximum string Voc at lowest site temperature | IEC 61643-31 |
| Cable ties, glands, labels, ferrules and marking | Lot | UV-stabilised ties; permanent cable identificationAdded | Small line, real cost at scale |
Rule of thumb for cable: routed length typically runs 1.15–1.25× the straight-line SLD distance once you add elevation, obstacle routing and termination loops. Use the cable schedule as the source document — the ratio above is a sanity check, not a substitute for it.
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AC-Side Electrical and Evacuation
Grid connectivity, metering and the HT items small BOQs forget
| Line item | Unit | Key specification | Compliance flag |
|---|---|---|---|
| AC distribution board (ACDB) | Nos | MCCB rated, IP54 minimum, busbar rating stated | IS 8623 / IEC 61439 |
| AC power cable — inverter to transformer / grid | m | Armoured XLPE, cross-section from load and derating factors | IS 7098 (XLPE) / IS 1554 (PVC) |
| Step-up transformer | Nos | kVA rating, vector group, CRGO core, losses guaranteed | Often missing in small BOQs |
| HT panel / RMU / VCB with protection relays | Nos | Rated voltage and breaking capacity; numerical relayAdded | CEA safety regulations |
| HT cable, terminations and jointing kits | m / Set | Heat-shrink or cold-shrink kits, quantity per terminationAdded | Kits routinely under-counted |
| CT/PT metering cubicle and ABT / special energy meter | Nos | Accuracy class, DISCOM-approved makeAdded | State DISCOM specification |
| Net meter / bi-directional energy meter | Nos | DISCOM-approved make, ToD capable where required | State metering regulations |
| AC surge protection device (Type I / II) | Nos | Rated for AC bus voltage and expected surge exposure | IEC 61643-11 |
| Evacuation line — poles, conductor, insulators, right of way | km | As per DISCOM sanction letterAdded | A whole scope, not a line |
Earthing, Lightning Protection and Safety
The most under-specified section in contractor BOQs
| Line item | Unit | Key specification | Compliance flag |
|---|---|---|---|
| Earth electrodes / pits — equipment and structure earthing | Nos | Copper-bonded rod or GI plate; count and depth derived from the earthing design and measured soil resistivityCorrected | IS 3043 |
| Earth ring conductor | m | 25×4 mm GI flat or equivalent copper; measure the full ring from the earthing layout | Measure, do not assume |
| Soil resistivity test and earth resistance test report | LS | Four-probe test before designAdded | Determines electrode count |
| Lightning protection system | Nos | Conventional air terminals, down conductors and dedicated earth per IS/IEC 62305; if an ESE terminal is proposed it is governed by NF C 17-102, not IEC 62305Corrected | Need established by IEC 62305-2 risk assessment, not by plant size |
| Safety kit — rubber mats, danger boards, shock-treatment chart, first-aid box, sand buckets, CO₂ / DCP extinguishers | Set | As per CEA safety regulations | Often billed as lumpsum and under-costed |
| Perimeter fencing and gates | Rm | GI chain link, barbed wire or wall as per site | Frequently excluded in error |
| CCTV, anti-theft fasteners, security cabin | Set | Camera count and recording retentionAdded | Insurer may require it |
Civil Works, Monitoring and O&M Infrastructure
Chronically underbid — include everything
| Line item | Unit | Key specification | Compliance flag |
|---|---|---|---|
| Foundations / plinths — module rows, inverter room, control panel | m³ | Concrete grade per structural drawing, PCC and reinforcement separately | Take from structural engineer |
| Cable trench excavation, sand bedding, brick protection and backfill | Rm | Depth and profile per cable layout drawing | Measure from cable layout |
| Site grading, approach road, drainage and culverts | m² / Rm | As per topographic surveyAdded | Whole line often absent |
| Weather monitoring station | Set | Pyranometer (POA + GHI), module and ambient temperature sensors, anemometerAdded | Mandatory in SECI / NTPC scopes |
| SCADA / remote monitoring infrastructure | Set | Web-based, logging interval stated, data retention period | Mandatory in SECI / NTPC contracts |
| Module cleaning system and water source | Set | Manual, semi-automatic or robotic; plus borewell or tank, pump and pipingExpanded | Water source is a real cost, not an assumption |
| Mandatory spares for the O&M period | Set | Spares list as specified in the tenderAdded | Contractually required |
| Commissioning, testing and documentation | LS | Pre-commissioning tests, PAC/SAC, O&M manuals, as-built drawings, training | Required for handover and release of retention |
Statutory, Commercial and Risk Items
The section most BOQs do not have at all
| Line item | Unit | What it covers | Why it matters |
|---|---|---|---|
| Electrical Inspector / CEIG approval and drawing charges | LS | Statutory fees, drawing submission, inspection | Non-negotiable and unrecoverable if unpriced |
| DISCOM connectivity, supervision and net-metering charges | LS | Application, feasibility, supervision and testing fees | Varies by state, sometimes materially |
| Insurance — erection all-risk, transit, third-party | LS | Cover from despatch to PAC, plus the O&M period | Typically 0.15–0.4% of contract value |
| Freight, unloading, internal shifting and storage | LS | Including module handling and site warehousing | Modules are bulky and fragile |
| Third-party inspection and factory acceptance testing | LS | Inspection agency charges, travel, witness testing | Client-mandated in most PSU tenders |
| Bank guarantees — EMD, performance, advance | LS | Commission plus margin money blocked for the tenor | A financing cost, price it as one |
| GST treatment | % | Concessional rate on the goods portion, standard rate on services; state the split you have assumed | Wrong split silently eats margin |
| Price variation / escalation clause | — | Whether module, copper and steel movement is passed through | If absent, you carry the commodity risk |
| Energy storage (where mandated) | kWh | Battery racks, PCS, EMS/BMS, HVAC, fire suppression, containerisation | Increasingly bundled into RE tenders |
The 6 BOQ Mistakes That Cost EPC Firms the Most
Estimating DC cable by SLD distance, not actual run
Single-line diagrams show electrical connectivity, not physical routing. Actual run includes elevation, routing around structures and loop allowance at every termination.
Typical overrun: 15–25% more cable than the BOQ carries
Naming the manufacturer instead of the ALMM model code
ALMM is enforced model by model. "Waaree 540 W" is not sufficient — the BOQ must carry the exact List-I model code, and a model quoted at bid stage may be delisted by the time you procure.
Consequence: disqualification in government tenders
Missing the earthing conductor ring measurement
Most BOQs list earth pits correctly but understate the GI flat ring that connects them. For a 1 MW array the ring alone can run 500–700 m, plus the electrodes it serves.
Typical overrun: ₹0.7–1.5L on a 1 MW project
Leaving SCADA and monitoring out of the BOQ
Remote monitoring, SCADA and the weather station are mandatory in SECI, NTPC and most DISCOM contracts. Added later as a variation, they become a negotiation you will lose.
Typical addition: ₹4–12L depending on project size
Reusing last project's cable specification
Cable cross-section follows current and permissible voltage drop, not project size. A longer string run or higher ambient on a new site can push you from 4 mm² to 6 mm².
Consequence: overheating, inverter trips, warranty exposure
Omitting civil and statutory quantities from the electrical BOQ
Trench excavation, foundation concrete, cleaning water source, CEIG fees and DISCOM charges get split into a "separate" BOQ — and then forgotten in the cost estimate entirely.
Typical overrun: ₹8–20L on a 5 MW project
The BOQ-to-Procurement Workflow
Lock the engineering design before starting the BOQ
A BOQ built on a preliminary design is a liability. The single-line diagram, layout plan, string sizing, earthing layout and cable schedule must all be finalised and signed off first. Design changes after BOQ submission become variation disputes.
Use the cable schedule — never the SLD — for cable quantities
The cable schedule lists every run with routed length, cross-section and termination allowance. It is the source document for the DC and AC cable BOQ. If the cable schedule does not exist yet, the BOQ is not ready.
Verify ALMM status for every model on the day you submit
Check the live MNRE portal, not a cached list, for every module model in the BOQ, and record the revision date against the line item. Keep a pre-approved alternative for each model in case of delisting between bid and procurement.
Price against current market rates, not last quarter's POs
Domestic DCR TOPCon module prices moved from roughly ₹27/Wp in January 2026 to ₹22/Wp in April, then rose again in May. Copper tracks LME; structure steel tracks domestic HRC and zinc. Reprice, every bid.
Add a 3–5% procurement contingency on BoS — and hold it
Module and inverter quantities are exact. Cables, connectors, clamps and fasteners are not: allow 3–5% for wastage, measurement variance and site conditions. This protects margin without moving your bid price materially.
Cross-check line-by-line against the tender BOQ before submission
Most government tenders issue their own BOQ format. Any item in the tender BOQ that is absent from your internal BOQ is a gap that converts into a cost overrun the day you win.
Map every BOQ line to a PO line before mobilisation
If a BOQ item has no owner, no vendor and no lead time attached to it, it will be procured late and at spot price. The BOQ-to-PO map is what turns the document into a procurement plan.
What a BOQ Pricing Error Actually Costs
Four ordinary BOQ errors — none of them exotic — take margin from 7% to under 5% on a single project. Run four or five similar projects a year with the same gaps and that is ₹1.5–2 crore of avoidable margin erosion annually. That is the real cost of a weak BOQ process, and it compounds quietly because no single line item ever looks large enough to escalate.
Pre-Submission BOQ Checklist
Run every bid through this before it goes out. It takes about 30 minutes.
Modules: exact ALMM List-I model code included, BIS registration confirmed, DCR status stated, performance and product warranties separated.
ALMM List-II: project category identified (bid date, commissioning date, net metering / open access / captive), exemption position documented in writing.
Inverters: IEC 62109 certification and IS 16221 / IS 16169 BIS registration confirmed, grid-protection settings referenced, SCADA compatibility noted.
DC cable: quantities taken from the cable schedule, cross-section calculated from current and voltage drop, wastage allowance added.
Mounting structures: wind-zone-matched structural design, IS 2062 grade and galvanising thickness specified, foundation bolt material confirmed.
Earthing: electrode count derived from soil resistivity test, ring conductor measured from the earthing layout drawing, IS 3043 compliance stated.
Lightning protection: need established by an IEC 62305-2 risk assessment; if an ESE terminal is offered, the governing standard is stated correctly.
AC and HT side: transformer, RMU/HT panel, termination kits, CT/PT cubicle and DISCOM-approved meter all included; evacuation line scoped.
Monitoring: SCADA and weather station in the BOQ, logging interval and data retention specified, remote access provision confirmed.
Civil works: trench quantities from the layout drawing, foundation concrete from the structural design, grading and approach road included, cleaning water source priced.
Statutory and commercial: CEIG and DISCOM charges, insurance, freight, third-party inspection, bank guarantee cost and GST split all carried as line items.
Commissioning: testing, PAC/SAC documentation, O&M manuals, as-built drawings and mandatory spares included as priced items.
Pricing: every rate verified against current market prices — not last quarter's POs or last project's invoices — and a price-variation position taken.
Tender alignment: your BOQ cross-checked line-by-line against the issued tender BOQ, with no missing items and no unpriced provisional sums.
Key Takeaways
A solar BOQ has eight sections, not six.
Modules and inverters get specified carefully. Earthing conductors, monitoring, civil works, commissioning documentation and the entire statutory-and-commercial block are routinely thin or absent.
Measure cables — never estimate them.
The single largest source of BOQ overruns is DC cable quantities taken from SLD distance instead of the cable schedule. Routed length typically runs 15–25% above the straight line.
ALMM compliance is model-level, and the rules changed twice this year.
Your BOQ must reference the exact List-I model code, and your List-II position depends on bid date, commissioning date and project category after MNRE's 18 July and 4 August 2026 orders.
BOQ errors compound across a portfolio.
A 2% error on an ₹18 crore project is ₹36 lakh. Four projects a year with the same gaps is ₹1.4 crore given away — invisibly, one line item at a time.
Price against current rates, and say so in the bid.
DCR module prices moved by double digits inside a single quarter in 2026. A BOQ priced on last year's rates is a margin risk before procurement even begins; a price-variation clause is how you stop carrying that risk alone.
Frequently Asked Questions
How many sections must a solar BOQ have?+
Eight — modules, inverters and power conversion, module mounting structures, DC-side balance of system, AC-side electrical and evacuation, earthing and lightning protection, civil works and O&M infrastructure, and statutory/commercial/risk items. The last one is the section most BOQs omit entirely, because it does not look like material.
Can I calculate DC cable quantity from the single-line diagram?+
No. The SLD shows electrical connectivity, not physical routing. Use the cable schedule, which carries routed length, cross-section and termination allowance. Routed length typically runs 1.15–1.25× the straight-line SLD distance once elevation, obstacle routing and termination loops are added.
Is naming the module manufacturer enough for ALMM compliance?+
No. ALMM is enforced at model level. The BOQ must carry the exact List-I model code — "Waaree 540 W" is not a specification. Verify the model on the live MNRE portal on the day you submit, and keep a pre-approved alternative in case of delisting between bid and procurement.
Does ALMM List-II apply to my project?+
It depends on bid date, commissioning date and project category. Competitively bid projects with bid submission on or before 31 August 2025 remain exempt. Net-metering and open-access projects commissioned on or before 31 December 2026 are outside List-II. PM Surya Ghar residential net metering is exempt until 31 March 2027. Behind-the-meter private captive sits outside both lists.
Is DCR the same as ALMM?+
No. MNRE has confirmed the List-II orders do not change DCR provisions. A module can be listed on ALMM List-I and still fail DCR. Price DCR and non-DCR modules as separate line items — the price gap is large and it moves.
How much contingency should a solar BOQ carry?+
Module and inverter quantities are exact, so they need none. On balance of system — cables, connectors, clamps and fasteners — allow 3–5% for wastage, measurement variance and site conditions. That protects margin without materially moving your bid price.
- MNRE Office Memorandum, 18 July 2026 — ALMM List-II for solar PV cells: limited window to 31 December 2026 for net-metering and open-access projects.
- MNRE Office Memorandum, 4 August 2026 — category-wise clarification on ALMM List-II applicability (bid dates, PM Surya Ghar to 31 March 2027, behind-the-meter captive, government building rooftop).
- MNRE ALMM List-I revision dated 3 August 2026 — cumulative enlisted module capacity 217,107 MW; 9th revision of ALMM List-II dated 21 August 2026.
- MNRE, March 2026 — ALMM List-III for solar ingots and wafers, effective 1 June 2028.
- JMK Research Monthly RE Update, January–May 2026 — domestic module price trends (Mono PERC, TOPCon, DCR TOPCon).
- Indian standards referenced: IS 2062, IS 4759, IS 875 Part 3, IS 3043, IS 7098, IS 1554, IS 16221, IS 16169. International: IEC 61215, IEC 61730, IEC TS 62804, IEC 61701, IEC 62716, IEC 62109, IEC 62852, IEC 61643, IEC 62305, EN 50618 / IEC 62930.
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Published 3 August 2026 · Headsup B2B Editorial Team · Procurement Intelligence
