Unlimited energy supply from the sun
Solar power converts sunlight into energy, primarily through two main technologies: solar photovoltaic (PV) and solar thermal. Solar PV uses the photovoltaic effect whereby semiconductor material in a solar cell absorbs sunlight to produce electricity. Solar thermal uses mirrors to concentrate sunlight – either on a central tower receiver or within parabolic trough mirrors – to produce extreme temperatures that are absorbed by a heat transfer medium, such as molten salt. This super-heated medium is then used to create steam to power a steam turbine and generator.
What role does solar power play in the energy transition?
With costs associated with solar PV falling by nearly 90% over the past decade , alongside the speed and ease of deployment, this technology is expected to be one of the main sources of electricity in our decarbonized energy future. By some estimates, it could provide up to 43% of global power generation by 2050.
For its part, solar thermal – also called concentrated solar power (CSP) − can help address the intermittency of solar power, since the thermal heat generated can be stored with the help of molten-salt energy storage for up to 16 hours. During that time, whenever the grid requires electricity, regardless of whether it is day or night, sunny or cloudy, the system can produce power. As well, given current technology, molten-salt energy storage is less expensive than battery electric storage.
Challenges and disadvantages
The most significant disadvantage of solar power is that it can generate electricity only when there is sunshine. Adding energy storage solutions can help the system address intermittency, while the addition of gas power can create a dispatchable low-carbon hybrid system. Likewise, solar thermal combined with molten-salt storage can bridge overnight or short periods of cloud cover.
We’re convinced that concentrated solar power combined with the molten-salt energy storage is cost-effective and the right technology for the future.
How solar thermal contributes to the energy transition
The German Aerospace Center’s (DLR) Institute of Solar Research is developing a concentrated solar power (CSP) pilot project that incorporates a molten-salt energy storage system (MOSAS) from MAN Energy Solutions. The 55-meter central tower is surrounded by nearly 2,000 mirrors that reflect the sunlight onto the central tower receiver, which uses MAN technology designed for temperatures up to 600°C. The project is monitoring how all parts of the system hold up at these high temperatures, which are desirable because they improve the heat-to-electricity efficiency and lower the overall cost of energy from the system.