Energy

Energy storage advance readies concentrated solar power for the smart grid

Energy storage advance readies...
Concentrated solar thermal power plants, such as this one in the California Mojave Desert, could soon form a part of the smart grid thanks to a system developed at OSU
Concentrated solar thermal power plants, such as this one in the California Mojave Desert, could soon form a part of the smart grid thanks to a system developed at OSU
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In the charging phase, heat from a CSP collector breaks down strontium carbonate into strontium oxide and carbon dioxide; during discharge, the process is reversed and heat is released to power a turbine
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In the charging phase, heat from a CSP collector breaks down strontium carbonate into strontium oxide and carbon dioxide; during discharge, the process is reversed and heat is released to power a turbine
Concentrated solar thermal power plants, such as this one in the California Mojave Desert, could soon form a part of the smart grid thanks to a system developed at OSU
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Concentrated solar thermal power plants, such as this one in the California Mojave Desert, could soon form a part of the smart grid thanks to a system developed at OSU

The intermittent nature of renewable energy sources is a huge burden on the power grid, making flexible and economical energy storage an essential step to a greener future. Researchers at Oregon State University (OSU) and the University of Florida have now devised a way to conveniently store and release energy harvested through concentrated solar power (CSP) plants, improving on the cost and energy density of previous systems and preparing this technology for the smart grid.

While standard solar panels convert sunlight directly into electricity, concentrated solar power plants focus an array of mirrors onto a solar receiver and use the resulting heat to drive an electricity-generating steam turbine. These systems tend to be low-cost, safe, long lasting and highly efficient, but they must be coupled to powerful and flexible energy storage to work at full effect.

Current systems that store energy from CSP power plants are too bulky and expensive to be practical, but a promising new approach known as thermochemical energy storage (TCES) holds the promise of a ten-fold increase in energy storage density at a fraction of the cost. This technology works similarly to a normal battery, except the chemical reactions that drive it are designed to absorb or release large quantities of heat with each charge and discharge cycle.

In a move that could pave the way for CSP to play a larger role within the smart grid, Nick AuYeng and the OSU team have now devised a high-performance TCES system that is about as energy-dense as a lithium-ion battery and only relies on commonplace, environmentally friendly, nonflammable materials.

The system can store energy indefinitely by using the heat from a CSP collector to break down strontium carbonate into strontium oxide and carbon dioxide. When the device is discharged, the two chemicals are recombined and, in the process, release a large amount of heat that can be used to power a turbine.

In the charging phase, heat from a CSP collector breaks down strontium carbonate into strontium oxide and carbon dioxide; during discharge, the process is reversed and heat is released to power a turbine
In the charging phase, heat from a CSP collector breaks down strontium carbonate into strontium oxide and carbon dioxide; during discharge, the process is reversed and heat is released to power a turbine

According to the researchers, the energy efficiency of TCES systems is closely related to their maximum operational temperature. While previous systems would peak at a relatively modest 600° C (1,100° F), the new advance doubles that figure and means that the residual heat from each energy discharge could be used to drive a second turbine for an even better return.

The team reports that the system can store an impressive 1,450 MJ of energy per cubic meter (403 Wh/l), which is comparable to the volumetric density of a lithium-ion battery. Unlike the battery in your smartphone, however, the device capacity was revealed to drop by about 15 percent after 45 charge/discharge cycles due to changes in the underlying chemicals.

Next up, the researchers will be working on addressing this issue to extend the life of the device. The scientists then plan to scale the system up in size in preparation for more testing at a national laboratory.

The findings appear in the latest edition of the journal ChemSusChem.

Source: Oregon State University

8 comments
Cuckoo
I can't wait for one of these storage technologies to become viable. It will go a long ways to shutting up renewable skeptics for good.
Mel Tisdale
@ cuckoo
Perhaps the most telling part of your comment is the expression that you "can't wait". Time is not on our side when it comes to replacing fossil fuels with greener energy sources.
The way things are speeding up on the climate change front, we can't be far off the point where all we will be able to do is cling on while the climate takes us wherever it will.
When that happens, it will be no good the sceptics uttering the immortal words "Oops, sorry!"
Firehawk70
The only thing that will shut up the skeptics is when reality beats the crap out of them. When starving people are knocking down their gated communities and killing them for their food in a Mad Max style beatdown. The only reason skeptics exist is: 1. oil/coal money spent on propaganda, 2. stupid people who believe it. Better renewable technology ain't gonna change either of those 2 items. Someone could perfect nuclear fusion tomorrow and those morons would still be walking around saying "we don't need to change anything, that climate change stuff is hooey, keep burning."
sl0r
Now if they could figure out a way for it to stop killing birds in mass it might actually end up being good for the environment...
Don Duncan
This is good news for centralized power distribution, e.g., grid. I'm waiting for a way to efficiently collect/store distributed (home) power. This would not be necessary if we had a free market in energy, but free markets do not exist anywhere.
Firehawk70: The MadMax senario is here now, just not televised. The bad guys wear uniforms and have the support of their victims. It's called "the US justice system" by those not subject to it (authorities), and by libertarians it's called "the US police state". By the majority it is ignored, sometimes with great difficulty, but blindness is less painful than the reality. Illusion makes no demands.
Chris Goodwin
"Skeptic knocking" again. The basic scientific stance is scepticism. It is not a matter of faith in a new technology - that is religion, AKA marketing hype. Yes, we have dreams, of flying like a bird, of curing cancer, of cheap energy direct from the sun, or fusion power, of economic "take off" - you name it. And there are always men ready to sell you the dream. Think Tesla - and think again. That is, be sceptical.
"Things" are a-happening. There will doubtless be great improvements, soon. But of the many that try something, many will fail. Watch out below.
John Banister
@ Don Duncan From Oct 7: "A team led by researchers from Sandia National Laboratories has shown that molybdenum disulfide (MoS2), exfoliated with lithiation intercalation to change its physical structure, performs as well as the best state-of-the-art catalysts for the hydrogen evolution reaction (HER) but at a significantly lower cost." Combine that with metal hydride storage and the Home Energy Station for the Honda FCX, and I think you're pretty close to there on the home front.
S Michael
Big Energy monopolies love this type of development. They of course will tell you, the little people, that it cost millions to build and maintain. So they are sorry but you will have to pay a lot more for your electricity. Never mind the Government, gave most of the money to them to build the operation. The cost per Kw will be pennies, but they will sell it to you for dollars. They have to keep up their lifestyle you know.....