Renewable Energy Glossary

Understanding key renewable energy terminology, in an ever-evolving technological landscape, is crucial for navigating the complexities of this sector. This glossary of terms, with a keen focus on battery energy storage and related areas, serves as a valuable resource for professionals operating in and around the market.

Hopefully this demystifies technical jargon and clarifies concepts that are fundamental to the industry. By providing clear and comprehensive definitions, this glossary aids in fostering a deeper understanding of the technologies, policies, and market dynamics shaping the future of renewable energy.

Energy storage

Energy storage refers to the capture of energy produced at one time for use at a later time. Energy storage systems can include physical, thermal, and battery storage, and are essential in balancing energy supply and demand, especially in renewable energy systems where production can be intermittent.

Battery Energy Storage System (BESS) 

A BESS is a technology primarily used for storing electrical energy through batteries, often for later use. It plays a crucial role in managing power supply-demand, enhancing grid stability, and facilitating the integration of renewable sources like solar and wind.

Energy Management System (EMS)

An Energy Management System (EMS) monitors, controls, and optimises the performance of energy generation and consumption units. In renewable energy, it’s crucial for ensuring efficient use of resources, managing demand, and reducing costs.

Net zero 

Net zero is a state or process where the total greenhouse gases emitted are equal to those removed from the atmosphere. In the energy sector, achieving net zero means producing energy without net emissions, often through renewable sources and efficient energy use.

Fully funded energy systems

Fully funded energy systems from Wattstor enables sites to create significant savings, make money from electricity markets, boost green credentials, and stabilise electricity prices. All without the typical CapEx risk involved with energy storage projects.

Renewable electricity

Renewable electricity is electricity that’s generated from renewable energy sources like solar, wind, hydro and geothermal. Unlike fossil fuels, these sources are replenishable and have a lower environmental impact, making them key to sustainable energy strategies.

Grid constraints

Grid constraints are the inherent limitations and challenges in the electricity grid that affect the transmission and distribution of electricity. These can be due to physical limitations, regulatory issues, or capacity challenges, and can impact the integration of renewable energy into the grid.

Wholesale trading

Wholesale trading refers to the buying and selling of electricity in large quantities, typically between generators and retailers or large consumers. In renewable energy, this can include trading energy generated from sustainable sources in the wholesale market.

Intra-day trading 

Intra-day trading refers to the buying and selling of electricity within the same day. It’s important in the renewable energy sector for managing the variability of energy supply, especially from sources like solar and wind.

Day ahead market 

A day ahead market is a market where energy is bought and sold one day before it’s delivered. This is crucial in renewable energy for planning purposes, as it allows for better integration of variable sources like wind and solar into the energy mix.

Ancillary services 

Ancillary services are services necessary to support the transmission of electricity from producers to consumers. In the context of renewable energy, they include maintaining grid stability and ensuring reliable supply despite the variability of renewable sources.

Price volatility

Price volatility refers to the rapid and significant changes in energy prices. In renewable energy, price volatility can be influenced by factors like weather conditions affecting supply, policy changes, or market demand.

Market leading 

Market leading is a term referring to entities or technologies that are at the forefront in their sector. In renewable energy, market-leading technologies or companies are those pioneering new solutions or dominating the market in terms of innovation or market share.

Solar Photovoltaic (PV) 

Solar PV is technology that converts sunlight into electricity using photovoltaic cells. It’s a key component of renewable energy, allowing for the harnessing of solar energy for power generation.

DC coupled system 

A DC coupled system is a configuration where solar PV and battery storage are directly connected on the DC side, enhancing the efficiency of energy storage and retrieval, and is particularly useful in renewable energy systems like the ones provided by Wattstor.

Alternating Current (AC)

The Alternating Current is a type of electrical current where the flow of electric charge periodically reverses direction. In the context of renewable energy, AC is often the final form of electricity delivered to consumers.

Direct Current (DC) 

The Direct Current is a type of electrical current where the electric charge flows in one direction. In renewable energy, DC is typically generated by sources like solar panels before being converted to AC for grid compatibility.


Onsite refers to renewable energy generation or storage systems located at the point of consumption, like solar panels on a building. This approach can reduce transmission losses and dependency on the grid.