Power Generation

The power plant will be situated on a 10,000 hectare site in Southern Tunisia. The project will consist of circa 18 x 125MW CSP Towers with molten salt storage producing an annual solar output of more than 10,000 GWh pa (for full 2.25GW)

Why Tunisia?

  • High CSP solar radiation potential in Tunisia
  • Tunisia has up to 20% better radiation than the best sites in Europe
  • Potential for large-scale projects, creating valuable economic activity on the vast land area in the desert
  • Land requirements are small relative to available surface area. The total size of the land is ca. 10,000ha, which represents only 0.06% of Tunisia’s surface area and less than 0.2% of Tunisian desert surface area.

TuNur conducted detailed studies on the site including:

  • Solar measurement
  • Environmental analysis
  • Socio economic analysis
  • Geotechnical and soil analysis
  • Water consumption and sources study

CSP Tower technology

CSP Tower technology uses a field of flat mirrors, known as heliostats that track the sun and reflect and concentrate the sun rays onto a boiler located atop a tower (“the Central Receiver”). The Central Receiver then converts the concentrated solar energy collected from the total surface of the heliostats into heat in the form of steam which is later sent to a traditional steam turbine generator to generate electricity.

TuNur has chosen to deploy CSP tower technology because it offers many advantages:

  • CSP towers haves high electrical efficiency as there are higher concentration ratios involved in this CSP technology due to the greater reflective area
  • When coupled with a thermal storage system, the system can produce electricity at night and even during cloud transients
  • Low capital costs are associated with this technology as flat mirrors are cheaper and easier to supply locally than curved mirrors which are needed for other CSP technologies
  • An air-cooled condenser can be used during the condensation process meaning that CSP tower plants have low water consumption up to 90% lower than other CSP technologies
  • CSP towers have higher thermal efficiency as heliostats track the sun on two axes rather than one
  • Solar tower power plants do not require completely flat land and can be built on varying terrains

Thermal storage

CSP with thermal storage delivers 100% solar energy, firm and predictable

  • The output from CSP is stable, more controllable and predictable due to the solar thermal storage technology used.
  • CSP plants integrated with thermal energy storage can extend electricity production into later parts of the day and after sundown.
  • It accounts for the variable nature of other intermittent resources such as photovoltaic and wind.
  • Less requirements for back-up generating capacity
  • Less operating reserves because of less intermittency
  • Is a proven technology at commercial scale