Crescent Dune – Concentrating Solar Power Plant

Somewhere between Las Vegas and Reno, deep in the Nevada desert, stands alone, a white tower which is 195 meters tall, that tends to glow like a beacon.  It is bounded by more than 10,000 billboard size mirrors that seem to focus the rays of the sun on its tips.

The `concentrating solar power’ plant – Crescent Dune, seems like some sort of an advanced communication device for strangers. However, the invention of the facility is in the fact that it can stock electricity and make it accessible on demand at any part of the day or night.

The flagship project of Santa Monica–based firm SolarReserve, Crescent Dune, has accomplished what the engineers as well as proponents of renewable energy had worked hard for decades; offering cheap, commercial-scale; non-fossil fuel electricity while winds tend to be calm or the sun does not seem to shine.

The facility is advertised as the first solar power plant which can amass over 10 hours of electricity that tends to translate into 1,100 megawatt-hours adequate to power 75,000 homes.  SolarReserve CEO Kevin Smith had commented that they can ramp up electricity generation for utilities depending on the demand and turn on when they need them to turn on and off when they want them to do so.

Physical/Thermal Properties – Molten Salt – Good Applicant – Energy Storage

The purpose is to have all the mirrors heat up a huge tank full of sodium and potassium nitrates which are pumped up to the top of the tower where the molten salt could reach a temperature as high as 565° C. Whenever the need of electricity arises, the hot salt is utilised to boil water producing high temperature, high pressure steam that turns the turbines that tends to generate electricity.  Remaining of the time, the molten salt is stored in another insulated tank on the ground.

According to cliff Ho, an engineer at Sandia National Laboratories who had studied heat transfer and fluid mechanics for technologies like concentrating solar power, though is not involved in the project, states that the physical as well as the thermal properties of the molten salt makes it mostly a good applicant for energy storage and can be pumped like water and stored in tanks.

Eliminate Expensive Heat Exchanger between Various Fluids

Ho explains that while a handful of other concentrating solar plants across the world tend to utilise solar rays to heat water directly into steam, it seem much more volatile than molten salt and cannot be stored easily.

That is the reason why the Ivanpah Solar Electric Generating System in California which is the largest concentrating solar-thermal plant at 377 megawatts, in the worlds seems to have no way of storing all the energy it tends to produce.Still, few of the other plants such as the Solana Generating Station in Arizona have utilised molten salt as medium of storage, they tend to heat the salt indirectly, using solar energy first to heat other fluid like oil.

However the advantage of utilising molten salt as energy collector which develops steam as well as the energy storage mechanism is that it seems to eliminate the requirement of expensive heat exchangers between various fluids.  With molten salt, Crescent Dune has the possibility of operating at a much higher temperature than the plants utilising other heat transfer fluids, making electricity generation much more efficient.Moreover, molten salt medium seems cheaper, environment-friendly, non-toxic and non-flammable when compared to oil.