--- title: Solar Glossary: EPC, CAPEX, I&C Terms | Arrays Ingenieria description: Plain-English definitions of solar terms: EPC, I&C, CAPEX vs OPEX, net metering, kWp, ALMM, pile foundations, DG synchronisation and more. url: https://arraysingenieria.com/solar-glossary/ last_updated: 2026-10-11 source: Arrays Ingenieria (Arrays Ingenieria Pvt. Ltd.) --- Solar Glossary # Solar Terms, in Plain English The words you will meet when planning a solar plant, from CAPEX and I&C to kWp and net metering. ## 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. [Read the FAQ](https://arraysingenieria.com/faq/)[Solar Guides](https://arraysingenieria.com/insights/)