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Sandy solution for renewable energy storage

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The Lead

sand power

SAND is emerging as a key ingredient in the race to develop a viable electricity storage system for renewable energies.

Latent Heat Storage has developed a low cost thermal energy storage system based on the latent heat properties of silicon derived from sand.­

The device – known as TESS – is being developed in South Australia with the help of an AUD $400,000 government grant to take it from prototype to commercial reality.

The TESS device stores electricity as thermal energy by heating and melting containers full of silicon. The high latent heat capacity and melting temperature of silicon makes it ideal for the storage of large amounts of energy.

Latent Heat Storage Chief Executive Officer Jonathan Whalley said storage was the next big challenge for energy generation worldwide.

“Renewable energy sources generally spill energy due to supply and demand mismatches, so we’ve designed the TESS device to capture this ‘spilt’ energy for later use or release to the grid,” Whalley said.

“Our system also means that energy consumers will be able to purchase stored electricity off-peak at low tariffs, which ultimately means cheaper energy.”

A key benefit of the TESS device is its capability to handle an increasing workload from 500kW applications through to an industrial scale of up to several hundred megawatt hours – enough to power about 7000 homes for a day.

The patented device is small enough to fit inside a 20-foot shipping container but is readily scalable as demand requires.

TESS is suitable for grid and off-grid applications and has been designed to overcome the intermittent nature of renewable energies such as wind and solar by providing a stable energy output suitable for base load power.

It can be integrated anywhere within an electricity network and is suitable for commercial and industrial businesses where heat and electricity are required such as hotels, schools and hospitals.

“After three years of research and development, our key objective now is to complete building a commercial prototype of the TESS device and start showcasing its potential to global markets,” Whalley said.

A commercial prototype will be ready in early 2016 to be used as a selling tool to potential clients and Whalley said devices would initially be built to meet the needs of individual sites rather than mass produced.

The Australian Government grant, through its Entrepreneur’s Programme, has been matched by Latent Heat Storage shareholders to generate $800,000 of total project funding.

The device has been developed in partnership with Adelaide-based engineering consultancy ammjohn, and final year engineering students at the University of Adelaide.

Whalley said the commercial introduction of energy storage systems would encourage more renewable energy generation such as wind farms and solar arrays.

“Energy prices are increasing around the world while storage technology costs are reducing, so we’re approaching the tipping point where energy storage systems are finally becoming commercially viable,” he said.

“We are developing an energy storage system to meet market demand … we anticipate that this will result in exponential growth of the energy storage market worldwide.”

Source: The Lead. Reproduced with permission.

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  • lin

    Very interesting. It would be good to know what the potential energy efficiency and cost per kWh this method would have compared to things like compressed air, pumped hydro or batteries.

    • john

      Using silicon the most abundant possibly material on earth may be low cost to acquire so this material can be used to store latent heat then turn it back into power by using that heat to drive a converter possibly a turbine possibly a more complicated method.

      Information on Silicon.
      Silicon (Si), a nonmetallic chemical element in the carbon family (Group 14 [IVa] of the periodic table). Silicon makes up 27.7 percent of Earth’s crust; it is the second most abundant element in the crust, being surpassed only by oxygen.

      A material that has wide temperature range to absorb heat and then release it is an obvious choice.
      The input figures from the grants are on an industrial scale not exactly very large.
      Now efficiency for this process.
      As lin mentioned is it above 80% or lower that will be the important aspect for this exercise?
      Pretty soon some research organisation is going to crack the cheapest most efficient method of storing energy, who ever finds that method is going to have a very large market because the total power need of Australia can be meet with solar energy perhaps just bypassing PV and using the concentrated heat of the sun to store energy to augment PV, Wind and Hydro.

  • GlennM

    Sounds great..
    but where is the technical info. how is the power converted to heat..and back again, what is the round trip efficiency ?

  • onesecond

    Costs per kWh or it didn’t happen.

  • nakedChimp

    Ok, heating up is simple.. just run electric current through resistive conductors and it get’s hot, no worries there.. 100% efficiency.
    But getting the heat back into electricity.. that’s the tricky part.
    Stirling, Carnot, etc. pp. comes to mind there.
    The efficiency of those conversion processes depends heavily on the temp difference of the 2 reservoirs of thermal capacity involved (one hot, the other ‘cold’ (*)) and there is always a part of the heat you can’t convert back to electricity – law of nature.
    If they co-use the stored thermal energy (the part they can’t convert into electricity) for building/process heat the efficiency goes up.
    So yeah, would be interesting to see some numbers for sure.

    *) That’s why they are trying to get the CSP plants as hot as they possibly
    can, while still maintaining material integrity at the solar heat
    absorbers at the top of that tower (which is the biggest problem afaik).

  • Ronald Brakels

    To me this looks like an insulated box full of sand with a steam generator attached. Cheap electricity goes and heats the sand and melts it. Then later, when electricity prices are higher, water is piped through and turned into steam which turns a generator to convert the heat into electricity. Silicon (sand) has a melting point of 1,414 degrees Celsius, so very high efficiencies are possible. But the higher the efficiency, the more this box of sand is going to cost. So they could go for 60% efficiency, which is very high but expensive. Or they could just go for 25% efficiency, including heat loss from the sand box, which would make things a lot simpler and allow cheaper, less heat resistant materials to be used.

    The best choice depends on the difference between the cost of electricity. for example, tonight in South Australia wholesale electricity might only cost 1.5 cents a kilowatt-hour, but thanks to a coming heat wave, tomorrow the electricity could be sold for $2 a kilowatt-hour or more for a huge profit, and a low efficiency doesn’t make much difference in that situation. But yesterday the cheapest electricity was 2 cents while the highest price was 6 cents. With 60% efficiency one could make money from that (assuming low operating costs) but with 25% efficiency it’s impossible, since if electricity is bought for 2 cents and only a quarter of it can be got back it has to be sold for over 8 cents just to break even.

    But there’s no reason why they can’t make sandboxes with different efficiencies for different purposes/customers if they want.

    Anyway, while this approach can’t match the high efficiency of batteries, provided reneable energy frequently drops the price of electricity down to, or close to zero, this will probably be the cheapest, or at least among the cheapest, forms of energy storage available, for utility scale storage anyway.

  • Steve

    There is a very annoying video circulating by a Dr. Kent Moor who’s degrees and background smack of huckster and snake oil salesman that drones on and on and on about the greatest energy breakthrough using sand at it’s core.

    It goes on with the snake oil pitch so long I have yet to last through to the end without swearing and punting it out.

    Does anyone have a link to something tangible from this guy’s ramblings?

    • Bild

      http://pro.moneymappress.com/EADSLR3979UP/PEADRC65/?iris=442305&h=true

      Perhaps this is it…seems like another stock scam.

      • Steve

        Yup. This is it.

        As best as I can find on that guy’s system is essentially the same as what is described in this article. The sand is simply used as a heat sink.

        Basically, this is essentially a manufactured geothermal cell or battery to hold solar heat.

        All these wonderful technologies based on solar fail to consider that most of the areas of high per capital energy use (like Canada) have vast areas of land that simply do not have enough solar energy per square metre for much of the year to make the technology viable with current lifestyle expectations.

        We have plenty of conventional energy left on this rock for decades to come. But it simply means using far less than we do now. Why do we all aspire to bigger houses and bigger or multiple cars…two of the most energy intensive uses for individuals in developed countries. Why is 2000-3000 square feet for 4 people considered normal for North America? Why do we “need” 6 -8-10 cylinder cars? Why do so many people drive pickups when they carry nothing more than the occasional Ikea shelving unit?

        If North Americans and other affluent countries lived more like the countries where energy prices are triple or quadruple of what they pay now, the world would be a better place.

        Remember the first R of the Reduce, Reuse and Recycle.

    • Dolphin

      I was looking for this comment. I started watching it too, and wow, whoever put that together really doesn’t grasp the concept of brevity. It’s all fluff… does he really expect to lure investors with a video that just never gets to the point?

  • dannyo66

    What do they do on a cloudy day or at night?