Active solar energy, particularly when generated by power plants, is primarily stored using methods specifically suited to the type of solar technology employed. According to recent information, the storage technologies most frequently coupled with solar power plants are electrochemical storage (batteries) with PV plants and thermal storage (fluids) with CSP plants.
Common Technologies for Storing Solar Power
While pumped hydropower is a common grid-scale storage method, solar power facilities typically utilize different technologies tailored to their specific energy output.
Storing Energy from Photovoltaic (PV) Plants
- Technology: Electrochemical Storage (Batteries)
- How it works: Photovoltaic (PV) panels directly convert sunlight into electricity (DC). This electricity can be used immediately, fed into the grid, or stored in large battery systems. Batteries store electrical energy chemically and can discharge it later when needed, such as after sunset or during periods of high demand.
- Coupling: Batteries are the most frequently coupled storage technology with PV plants.
Storing Energy from Concentrated Solar Power (CSP) Plants
- Technology: Thermal Storage (Fluids)
- How it works: Concentrated Solar Power (CSP) plants use mirrors to focus sunlight, creating intense heat. This heat is typically absorbed by a fluid (like molten salt or synthetic oil). This hot fluid can then be stored in insulated tanks. When electricity is needed, the stored heat from the fluid is used to create steam, which drives a turbine to generate electricity.
- Coupling: Thermal storage systems using fluids are the storage technologies most frequently coupled with CSP plants.
Comparing Solar Energy Storage Methods
Here's a quick comparison of the storage methods frequently used with large-scale active solar systems:
| Solar Plant Type | Primary Storage Technology | Stored Energy Form | Often Coupled With |
|---|---|---|---|
| Photovoltaic (PV) | Electrochemical Storage (Batteries) | Electrical | PV Plants |
| Concentrated Solar Power (CSP) | Thermal Storage (Fluids like molten salt) | Thermal (Heat) | CSP Plants |
The Role of Storage in Solar Energy Systems
Solar energy generation is intermittent; it only happens when the sun is shining. Storage is crucial for active solar systems, especially utility-scale plants, to:
- Provide power after dark.
- Smooth out fluctuations caused by clouds.
- Allow energy to be dispatched when demand is highest, not just when it's generated.
By storing energy, solar power plants can become more reliable and contribute more consistently to the energy supply.
