How it Works: Molten Salt Plant
The Solar Collector and Receiver System
- Cold salt (350⁰C) flows from the cold tank to the tower
- Reflected sunlight heats the salt flowing through the tower to 565⁰C
- Hot salt returns to the hot tank to for storage
- Hot salt flows from the hot tank to the steam generator
- The steam generator transfers heat from the salt to water to make steam
- The salt flows back to the cold tank
Molten Salt Storage Works
The eSolar molten salt system is based on a 50-MWt module composed of a tower-mounted molten salt receiver surrounded by a heliostat field utilizing eSolar’s small heliostat technology. This basic thermal module can be replicated, without scaling or redesign, as many times as required to create plant sizes from 50 to 200 MWe with capacity factors ranging from 20 to 75%. This building block approach allows us to address a broad range of customer requirements without significant redesign from peaker plants to base-load power plants.
Molten salt thermal energy storage is the most economical method to store solar energy and results in the lowest cost of electricity from a renewable energy source that is firm and dispatchable. Molten salt is a mixture of readily available and naturally occurring salts used in the agricultural business as fertilizer and thus inexpensive. When compared to a similar solar PV system with the same amount of storage and annual production, molten salt power towers are an order of magnitude less expensive.