# Solar Energy Terms Explained: A Singapore Glossary

kWp, ECIS, SCT, LEW: Singapore solar comes with its own vocabulary. Here is every term defined in one sentence each, in plain English.

**Quick answer:** Singapore solar comes with its own vocabulary, kWp, ECIS, SCT, LEW, DLP, GEF, and more, much of it specific to EMA and SP Group's regulatory framework rather than terms used in solar guides written for other countries. Below is every term defined in one sentence each, organised by category.

Singapore solar comes with its own vocabulary, much of it specific to EMA and SP Group's regulatory framework rather than terms used elsewhere. Below is every term a Singapore landed homeowner is likely to encounter, defined in one sentence each.

## System and generation terms

| Term | Definition |
| --- | --- |
| kWp | Kilowatt-peak. A solar system's installed capacity, how much power it can produce under ideal, standardised test conditions. |
| kWh | Kilowatt-hour. A unit of actual energy generated or consumed over time, the unit your SP Group bill is charged in. |
| Peak sun hours (PSH) | An annual average measure of usable sunlight intensity. Singapore averages 4.33 peak sun hours per day, already accounting for cloudy days across the year. |
| Degradation | The gradual decline in a panel's output over time, typically around 0.5% per year, meaning a panel still produces roughly 88% of its original output after 25 years. |
| Self-consumption | The share of your solar generation that your household uses directly, rather than exporting to the grid. Higher self-consumption generally means higher savings, since self-consumed power avoids the full retail tariff. |
| P50 / P90 | Statistical confidence levels used in generation estimates. A P50 estimate is expected to be met or exceeded 50% of the time; a P90 estimate is a more conservative figure expected to be met 90% of the time. |

## Financial and billing terms

| Term | Definition |
| --- | --- |
| Retail tariff | The rate you pay to buy electricity from the grid, currently S$0.3478 per kWh including GST. |
| SCT (Simplified Credit Treatment) | The export scheme for SP Group regulated-tariff customers, crediting exported solar at a fixed rate, currently around S$0.2581 per kWh, lower than the retail tariff. |
| ECIS | Enhanced Central Intermediary Scheme. The export scheme for customers buying electricity from an OEM retailer instead of SP Group, crediting exported solar at the variable half-hourly wholesale electricity price rather than a fixed rate. |
| NER / Net Export Rebate | Not a separate scheme. The name tied to the application form used to register for either SCT or ECIS. |
| Net metering | A billing approach used in some other countries where exported solar is credited at the same rate as imported electricity. Singapore does not use net metering; exported solar is credited at the lower SCT or ECIS rate instead, depending on your electricity plan. |
| Payback period | The number of years it takes a system's cumulative savings to equal its upfront installed cost, typically 4 to 5 years for a suitable Singapore landed home. |

## Regulatory and installer terms

| Term | Definition |
| --- | --- |
| LEW | Licensed Electrical Worker. A qualified professional legally required to sign off on a solar system's electrical design and installation in Singapore. |
| BCA ME03 | A licensing classification from the Building and Construction Authority that qualifies a contractor to carry out mechanical and electrical works including solar installation. |
| EMA | Energy Market Authority. Singapore's electricity regulator, responsible for grid safety rules including the anti-islanding requirement that shuts solar panels off during a blackout. |
| Anti-islanding | A required safety feature that automatically disconnects a grid-tied solar system during a grid outage, protecting utility workers repairing the fault. |
| Single-phase / three-phase | Two types of electrical supply. Single-phase caps a home in the roughly 10 to 13kWp range of solar capacity, confirmed case by case with SP Group; three-phase removes that ceiling. |

## Equipment and technology terms

| Term | Definition |
| --- | --- |
| Balance of System (BOS) | Every solar component besides the panels themselves: inverter, mounting, wiring, disconnects, and monitoring equipment. |
| PERC / TOPCon / HJT | Three successive generations of silicon solar cell design, each a real efficiency and heat-tolerance improvement over the last. |
| ABC (All Back Contact) | A cell design that moves every electrical contact to the rear of the panel, removing visible front-side wiring and improving efficiency. |
| IEC 61215 / IEC 61730 | The two core international certifications confirming a panel has been tested for durability (61215) and electrical and fire safety (61730). |

## Contract and sustainability terms

| Term | Definition |
| --- | --- |
| DLP (Defects Liability Period) | The window in a solar contract, typically around 12 months, during which the installer must fix workmanship defects at no extra cost. |
| GEF (Grid Emission Factor) | The amount of CO2 produced generating each kWh on Singapore's national grid, used to calculate a solar system's carbon offset. |
| REC (Renewable Energy Certificate) | A separate, tradable certificate proving a unit of renewable electricity was generated, distinct from the physical export credit a system earns. |
| Green Mark | BCA's certification scheme for building sustainability, where solar contributes as one criterion among several, not the certification itself. |
| GMIS-EB 2.0 | BCA's cash cofunding scheme for Green Mark retrofits, capped at S$1.5 million but requiring a 5,000 sqm floor area that excludes individual homes. |

**Further reading:** see [how solar export works in Singapore](/blog/what-is-ecis-singapore-solar) for the ECIS and SCT mechanics in full, and [solar payback period in Singapore](/blog/solar-total-cost-of-ownership-singapore) for how these terms combine into an actual return calculation. Run the [Sunnify solar estimate](/solar-estimate-singapore) to see these exact figures applied properly to your own specific home and roof.

## Frequently Asked Questions

### What is the difference between kWp and kWh?

kWp (kilowatt-peak) measures a system's installed capacity, how much power it can produce under ideal conditions. kWh (kilowatt-hour) measures actual energy generated or consumed over time. A 15kWp system does not generate 15kWh every hour; it generates roughly 15 kWh per kWp per year on average in Singapore, or about 16,600 kWh annually for a 15kWp system.

### Why does Singapore use different terminology from other countries' solar programmes?

Terms like ECIS and SCT are specific to Singapore's own regulatory framework, run by EMA and SP Group, and do not map exactly onto terms like net metering used elsewhere. Singapore actually runs two separate export schemes, SCT for SP Group regulated-tariff customers and ECIS for retailer customers, and neither credits exported solar at the same rate as imported electricity the way true net metering does, which is why the terminology and the mechanics both differ.