The BZE model of Gemasolar

Beyond Zero Emissions (BZE) often runs stalls at community events. BZE often has a model of the Gemasolar “concentrating solar thermal power plant” at these stalls. 

This page is to support BZE volunteers using the Gemasolar model.

On this page

  • Gemasolar: Spain
  • Sundrop tomato farm: Port Augusta
  • Aurora Plant: South Australia
  • BZE proposed building this plant
  • South Australia and renewables
  • BZE Zero Carbon Australia Plans
  • Crescent Dunes concentrating solar thermal plant: Nevada
  • Hazelwood coal-fired generator

The Gemasolar power plant

How it works

  • A Concentrating Solar Thermal power plant with storage
  • Mirrors collect sunlight to heat molten salts, boil water and generate electricity.
  • There are 2,650 mirrors that move continually, always focusing the collected sunlight onto the central tower.
  • Each mirror (heliostat) is about 12 x 12 metres, about 4 storeys high. They are in a circle of 1.5 km around the central tower.
  • They each focus the sunlight onto the central tower. This heats molten salts to about 565 C.
  • The hot salts then flow into the hot salt tank for use when needed, daytime or nighttime. 
  • The hot salts retain 99% of their heat over 24 hours.
  • The hot salts flow through a heat exchanger to boil water.
  • The steam drives a turbine to generate electricity.
  • The now-cooled molten salts then flow into the cold tank where the temperature is about 290 C.  The salts are then ready to flow into the tower again.

About Gemasolar

  • In Spain, west of Seville.
  • The first commercial-scale plant using this technology. 
  • Started May 2011.
  • Can produce electricity 24 hours a day
  • Longest recorded continuous operation has been 36 days.
  • Can generate for up to 15 hours without sunlight.
  • Registered electrical power: 17 Megawatt
  • Electricity to the grid: 80 Gigawatt-hours per year
  • Power for 25,000 homes
  • Torresolenergy: Gemasolar

In 2013 Gemasolar had a record-breaking run, producing electricity 24 hours a day for 36 consecutive days.
Solar storage plant sets record: Renew Economy

  • A megawatt is a unit of power: energy per second
  • A megawatt-hour is a measure of energy

Sundrop Farms: Solar tower powered tomato farm

  • The “Sundrop Farms” greenhouses grow tomatoes in nearly desert country
  • They use a Concentrating Solar Thermal generator to provide electricity, heat and desalinated water.
  • Sundrop Farms
  • Completed October 2016

(Port Augusta becomes Australian renewable energy hub: ABC October 2018)

Aurora solar: Thermal solar generator in SA

  • In South Australia, we were planning to build a plant like Gemasolar
  • Difficulties have arisen with financing the plant (April 2019)
  • About twice as big as Gemasolar
  • 150 Megawatts
  • Concentrating solar thermal with storage
  • Storage: 1,100 megawatt-hours
  • Built by Solar Reserve
  • Heliostats over 10,000

BZE proposed building this plant

  • In 2012, the BZE research report “Repowering Port Augusta” identified Port Augusta as the place to build a solar thermal power plant.
  • BZE advocated for this. The community supported it.
  • The South Australian government held an inquiry into the BZE proposal.
  • In 2017, the South Australian Government awarded a $650 million contract.
  • In 2019, the plan was dropped.

Crescent Dunes Plant: Nevada

  • Concentrating solar thermal plant with storage
  • Power 110 MW
  • Energy output: 500,000 Megawatt-hours per year
  • Energy storage 10 hours at full output
  • Molten salt lasts for 40 years with no degradation or replacement
  • Developed by Solar Reserve
  • First commercial plant using this technology in the USA
  • Entered commissioning phase in February 2014
  • Long periods of plant shutdown due to leaks in the storage tanks: 2017

Power Technology: Crescent Dunes Solar Energy Project: Nevada

Crescent Dunes (Wikipedia)

Hazelwood coal-fired plant, Victoria