Solar Terms, in Plain English

A

Accelerated depreciation

A tax benefit that lets a business that owns a solar plant write off its cost faster than normal assets, reducing taxable income in the early years. Available under the CAPEX model.

ACDB / DCDB

AC and DC distribution boards: the enclosures that house the fuses, isolators and surge protection between the modules, the inverters and the grid connection.

ALMM

Approved List of Models and Manufacturers: the list of solar modules approved by India's Ministry of New and Renewable Energy (MNRE) for use in government-linked projects.

ALMM List-II

MNRE's approved list of solar PV cell manufacturers. From 1 June 2026, projects covered by the ALMM order must use List-I modules made with List-II cells.

B

Balance of system (BOS)

Everything in a solar plant except the modules: mounting structures, inverters, cables, distribution boards, earthing, lightning protection and monitoring.

Bifacial module

A solar module that generates power from both sides, using light reflected from the ground onto its rear face.

C

CAPEX model

The owner pays for the solar plant upfront and owns it outright, keeping all the savings. Arrays Ingenieria builds plants on this model.

Commissioning

The final stage of a project: testing every component, synchronising the plant with the grid and handing it over as ready to generate.

CUF (capacity utilisation factor)

The energy a plant actually generates in a year as a percentage of what it would generate running at full capacity all year.

D

DCR (domestic content requirement)

A rule in some government schemes that modules and cells must be made in India.

DG synchronisation

Controls that let a solar plant run alongside diesel generators safely, reducing fuel use without back-feeding the generators.

E

Earthing

Connecting the plant's metal structures and electrical equipment to the ground so that fault currents and lightning are carried safely away.

EPC

Engineering, procurement and construction: a single contract covering the design, equipment purchase and building of the whole plant.

Ex-servicemen-led MSME

A micro, small or medium enterprise run by former members of the armed forces. Arrays Ingenieria is one, founded by Lt. Gen. A.R. Prasad (Retd).

F

Financial closure

The point at which a project's funding (equity and loans) is fully tied up, so construction can start. PM-KUSUM Component A and C projects must reach it by 30 November 2026.

G

Grid-connected (on-grid) system

A solar plant connected to the utility grid, which can draw from or export to the grid; the most common type for businesses.

Ground-mount solar

Modules installed on structures fixed to the ground, typically on pile foundations; used for tea estates, industrial land and utility parks.

Group captive

An arrangement where consumers take an ownership stake in an off-site solar plant and draw its power under captive-generation rules.

I

I&C (installation & commissioning)

The on-site work of building a solar plant to an agreed design and bringing it into operation: structures, modules, cabling, inverters, earthing, testing and commissioning.

Inverter

The equipment that converts the direct current (DC) from the modules into alternating current (AC) for use on site or export to the grid.

K

kWp / MWp

Kilowatt-peak and megawatt-peak: the rated DC output of a solar plant under standard test conditions. 1 MWp = 1,000 kWp.

L

Lightning arrestor

A device that intercepts lightning strikes and conducts them safely to earth, protecting modules and equipment.

M

MMS (module mounting structure)

The steel or aluminium frame that holds the modules at the designed tilt and orientation.

Module cleaning system

A pipe network with taps or nozzles across the plant so that modules can be washed regularly, recovering output lost to dust (soiling).

N

Net metering

A billing arrangement where the power a solar plant exports to the grid is offset against the power drawn from it.

O

OPEX / RESCO model

A developer (a renewable energy service company) finances and owns the plant, and the site owner buys its power at an agreed tariff. Arrays Ingenieria works as I&C or EPC partner to such developers.

P

Panchamrit

The five climate commitments India announced at COP26 in 2021, including 500 GW of non-fossil capacity by 2030 and net zero by 2070.

Performance ratio (PR)

Actual energy generated divided by the theoretical energy available from the sunlight; a measure of how well a plant is built and maintained.

Pile foundation

A steel or concrete pile driven or cast into the ground to anchor the module mounting structures of a ground-mount plant.

PM Surya Ghar: Muft Bijli Yojana

The central government scheme that subsidises rooftop solar for homes.

Puja (commissioning ceremony)

A traditional prayer held at a new plant, as at the inverters of the Borpatra Tea Estate solar plant at its inauguration in September 2026.

R

Rooftop solar

Modules installed on a building's RCC or metal-sheet roof, turning unused roof space into a power source.

S

SCADA / remote monitoring

Systems that record a plant's generation and faults in real time and make them visible remotely.

T

Tier-1 module

A module from a large, bankable manufacturer with an established production and financing track record.

TOPCon

Tunnel oxide passivated contact: a high-efficiency solar cell technology now common in new modules.