Solar glossary

The wholesale price of one kWh, set hour by hour on the Korea Power Exchange wholesale market. It is the base rate a solar operator receives for the power it sells, and the mainland and Jeju are calculated separately.

A certificate proving that electricity was generated from renewables. One REC is issued per MWh generated, multiplied by a weighting set by the type of installation.

The obligation on generators above a certain size to supply a set share of their total output from renewable energy.

A deployment regime in which long-term purchase contracts are awarded by competitive bidding within a tender volume set by the government. Due to take effect in 2027.

A contract fixing the combined SMP and REC rate for 20 years. It is awarded through competitive bidding and reduces exposure to price movements.

Connecting the electricity a plant generates to KEPCO's network. It requires spare capacity at the nearby substation and on the distribution line.

A rule requiring generating equipment to be installed a minimum distance back from housing or roads.

Forcing a plant to reduce or stop its output to keep the power system stable. It happens when generation exceeds demand.

The permit a local government issues for altering the form or quality of land, or installing a structure on it. It is the central approval for ground-mount solar.

The licence required under the Electricity Business Act to run a generating business. Up to 3 MW it sits with the local government; above that, with the Electricity Regulatory Commission at the Ministry of Trade, Industry and Energy.

Photovoltaics used as the building material itself — facade, glazing, roof, shading — rather than mounted on top of a finished building.

The conventional approach to solar on buildings: a support structure is fixed to a completed building and modules are mounted on it.

A building that minimizes energy use through high-performance insulation and on-site renewables. Certification runs from grade 1 to grade 5 according to the energy self-sufficiency rate.

Equipment that stores electricity in batteries so it can be used or sold at the moment it is needed.

Small, scattered resources — rooftop solar plants, storage — tied together by communications and software, then operated and traded as if they were a single power plant.

A power purchase contract signed directly between an electricity user and a renewable generator. In Korea it takes two forms: direct PPA and third-party PPA.

An international campaign in which companies commit to sourcing 100% of the electricity they use from renewables. Korea operates its own version, K-RE100.

A scheme under which a user pays KEPCO a premium on top of the standard tariff and is recognized as having used renewable electricity.

Using the electricity you generate at your own site instead of selling it to the grid. Every unit consumed is a unit off the bill.

Generating power from an array mounted above farmland while cropping continues underneath.

Replacing the modules, inverters, and other equipment at an aging plant with higher-efficiency products to restore output.

The party that finds a site, tests its feasibility, designs the commercial structure, and brings in the construction, financing, and other parties needed to realize the project.

Carrying out design, procurement, and construction as a single package, or the company that does so.

Running and maintaining a plant after commissioning: monitoring, scheduled inspection, fault response, and settlement management.