Thread: Energy Storage R&D beginning to find solutions for Renewables?

Intermittency is an ongoing limitation for wind and solar, feeding the reluctance and reservations about moving beyond supplementing existing energy supply to investing in these as primary, baseload sources. I think energy storage, especially large stationary storage, has been the neglected poor relation when it comes to energy R&D. It has different priorities than the kind of battery research that might lead to mass use of electric vehicles, which does have the mobile devices market to stimulate it.

I came across this use of heat pump techologies for electrical storage, to be trialled as a "...1.5-MW/6-MWh electricity storage unit on a U.K. primary substation in the Midlands region" (in UK). From the companies website (where exaggerated claims are possible) "We can achieve a levelized cost of storage (LCOS) of less than $35/MWh stored. We believe this to be the lowest price of any storage technology - including pumped hydro."



Is this evidence that energy storage solutions that can be deployed on a large scale and can significantly help match intermittent supply to variable demand are within reach?

Cheaper than pumped hydro! Excellent.

Is this evidence that energy storage solutions that can be deployed on a large scale and can significantly help match intermittent supply to variable demand are within reach?

I reckon this is the prime area for development/deployment in the next couple of decades. I see power technology as being very much in the same stage as computer operations of 20 to 30 years ago. And the centralised power generation operators as being very much like IBM and its cohort. They all resisted the newer technologies and approaches - and only IBM is left from that group. Who's going gangbusters? Distributed, portable and domestic computer technologies, that's who.

What I personally want is for the world's R&D projects to concentrate on my desire for domestic sized storage devices to enhance my rooftop solar. (So I can still have power on a hot, 42C, blustery day when the bushfires are raging. I wouldn't have to worry about transmission being shut down for safety reasons. My airconditioning is important.)

And I want them to be as cheap as or cheaper than an ordinary tablet computer. Not much to ask, surely.

Adelady, even modest domestic energy storage to carry the energy from rooftop solar through a single evening could become popular as 'smart' metering is rolled out and is found to impose a steep spike in price for power in the evenings. To have enough storage for a week could see grid connection become optional. Safe, simple and reliable energy storage could easily become a standard inclusion in homes and be a relatively small proportion of new home costs.

Even though 'utility' scale storage looks likely to become part of grid networks and ought to be able - because of economics of scale - do it cheaper than distributed domestic energy storage, the electricity sector is not very forward looking when it comes to low emissions energy from renewables. Stripped of their PR gloss, the largest incumbent players are almost universally opponents, not leaders, of action on emissions reductions. They only go along with renewable energy options under duress or via generous incentives and lack any burning desire to see them succeed - a recipe for poor implementation.

It's certainly the right problem to solve. Their website, however, is completely absent details, studies or published research sufficient to suggest this idea might be viable--I'd certainly want a LOT more detail before putting a cent into this project.

Lynx Fox, the trial plant - for which they have funding - should be an important test of the technology and for the company.

Most hyped new technologies fail to live up to expectations but amongst them and often indistinguishable in the early stages, will be technologies that work. I'm not sure all the failures are due to technologies lacking potential - poor implementation has to be a major factor and the people who can research an idea in the lab may not have the engineering, organisation and commercial skills to see it through.

As an aside, heat as energy storage medium has always had great potential for scaling up that's proven difficult to realise in practice - but heat pump technologies do seem to be proving themselves to be reliable and cost effective in other applications. As another aside I think the whole area of utility scale electrical storage is one that deserves a high level of R&D attention.

The downside of heat is the Carnot limit. Carnot cycle - Wikipedia, the free encyclopedia

Pumped storage may cost more, and may require fortunate geographic features in order to work, but it's also 70-85% efficient. No heat engine would likely ever be that efficient. I think they're only pointing out the cost of storing what they manage to store, and ignoring the cost of the electricity that gets lost from failing to store some of it.

As is usual the company isn't giving out a lot of detail; I would think that the Energy Technologies Institute that is providing project funding (and, Lynx, that includes an equity investment in the company) would have done some close scrutiny of the technology.

Kojax, The company is claiming 72 - 80% "round trip efficiency", which I took to be electricity in/ electricity out. I don't think I'm competent to comment on the Carnot Cycle implications, although the company website does talk about it. I don't know if it's possible to incorporate the use of waste or other low grade heat into the system but on the face of it it should.

The upside of heat as a storage medium is that it isn't constrained by geography or water availability and any storage system that can rival pumped hydro for cost would be very beneficial.

Aha! One of my favourite ideas ever is getting closer to commercial scale.

Liquid Metal Battery Startup Raises $15M in Additional Financing : TreeHugger

This is from Professor Sadoway earlier this year ... http://www.youtube.com/watch?v=Sddb0Khx0yA

I still love "...if you want to make something dirt cheap, make it out of dirt...."

Adelady - It's good to see some movement on a variety of fronts; multiple approaches suggest that there is plenty of scope for superior storage technologies to emerge. I did like the pumped heat idea because the materials used are abundant and not toxic - avoiding a future burden of toxic waste.

I've had some hopes for Vanadium Redox flow batteries - a lot of off-grid homes around here would benefit from it's expandable storage possibilities as well as being unfazed by full and prolonged discharge. Given most remote power systems use lead acid batteries that don't handle being deeply discharged (usable capacity if you want them to last being much less than total capacity) and don't handle being in a discharged state for prolonged periods (backup generator for prompt recharge being required if you don't want to kill them) having a storage system that actually looks suited to the purpose has to be an improvement. With VRB's increased electrolyte volume could replace the need for the backup generator. The possibility of a home delivery of fully charged electrolytes would be there as well. The electrolyte materials are toxic but at least they are endlessly re-usable and recyclable without degrading quality.

A new development that uses a similar concept of storage in liquid electrolytes independent of the charge/discharge stack (flow battery) is an attempt to develop flow capacitors. The idea is to overcome the storage capacity limits of capacitors whilst making good use of their rapid charge and discharge characteristics.

PS I found this - a household storage system for houses with grid feed solar - that allows PV to directly power a home when it's available, bypassing the meter, has sufficient storage to carry it through an evening, feeds excess to the grid and allows use of grid energy when required. Given that Feed in Tariffs are being cut back in parts of Australia with electricity providers urging 'market' rates equivalent to wholesale coal fired power (under 10c/Kwh) whilst charging domestic customers, PV fitted households included, 25c plus for energy used, having a system that allows direct use by Pv fitted houses could be be a cost saver. Combined with providers moving to 'smart metering' that sends evening electricity prices above 50c/kwh that looks like an incentive to have that bit of storage built in. As always the overall costs of the installation need to be considered, although they are claiming an expected 20 year working life.

New solar energy collector so efficient it works at night - Neoseekernfrared solar collector, better than solar panels, easier to produce and works day and night !!

But this technology has been out for over 4 years now has anybody heard anything on it ?

Originally Posted by garr

New solar energy collector so efficient it works at night - Neoseekernfrared solar collector, better than solar panels, easier to produce and works day and night !!

But this technology has been out for over 4 years now has anybody heard anything on it ?

Perhaps this from the article explains it?

"But! It's not all worked out yet. A big stumbling block remains. While these solar collectors are able to collect solar energy, they are currently unable to transmit this energy into usable electricity. The solar infrared rays hitting the nanoantennas generate a current that has a frequency which oscillates ten thousand billion times a second -- which is far to great of an oscillation that standard electrical appliances can handle. But the teams working on it: "At this point, these antennas are good at capturing energy, but they're not very good at converting it," INL engineer Dale Kotter said, "but we have very promising exploratory research under way."

Nantennas have a lot of potential both for collecting energy and as components of thermal energy storage systems. When it was suggested in a media article about them that they could become coatings used to convert waste heat to electricity my immediate thought was converting stored thermal heat to electricity. It's one of the technologies I think could have a profound impact if the current rectifying problem gets solved - Infra Red is not confined to daytime and it would lessen the need for storage for renewables - yet it would improve storage for renewables as well.

Nantenna - Wikipedia, the free encyclopedia

Electricity produced from a heat cell ie hot water system is not new. However not yet on the commercial market. It apes a Steam turbine generator but in place of water/steam driver force it relies on sealed Carbon Dioxide-CO2. 9 bar force is the minimum force for turbine generator drive. Graph for wattage is 9 bar force per litre per second produces 720 watts. Wattage increases by bar force or volume per second. Workable 9 bar CO2 pressure occurs at minus 10* Celsius. Plus 30* Celsius has a 60 bar force. Plus 60* Celsius is 175 bar force or the same force of Steam turbine generator of 350 megawatts. Plus 100* Celsius is 7,000 bar force. Unlike the Stirling engine which is piston new technology is turbine and that is its only moving part. Its operating system is very simple and a product not unlike the workings of a fridge. CO2 liquid in the boiler is heated to gas or gas made hotter. That gas goes to a turbine in place of restrictor plate. The hot force spent gas exiting the turbine enters a vacuum expansion chamber (like found in all fridges) where it instantly cools. A compressor (such as in an electric fridge) is etched into the turbine shaft. The compressor both draws vacuum to the expansion and conveys the cool gas or liquid back into the boiler.

DAS.jpg

Please note that CO2 at temperature above Plus 35* Celsius formates into Dry-Ice roughly 50/50 Dry-Ice-Hot gas. This leaves a permanent ice feild to which cooling tubes can pass through allowing greater potential of cooling before the liquid/gas is picked up by the compressor and conveyed back into the boiler.

Charts for CO2 are Web available. Below 31.2* Celsius is known as Critical and above 31.2* Celsius is Supercritical. Each has its own chart.

DasEnergy @14 - efficient conversion of low grade heat to electricity is something I believe would be of use for large scale energy storage - stirling engines seem to do the job but have so far failed the cost effectiveness part. Heat pump and refrigeration systems seem to have proven themselves to be reliable and efficient in a variety of situations. Do you have any links for the system you describe?

Hello Ken,

I am sorry to say I can only provide linkage by name. How Things Work- Electric Fridge. Hydro Turbine facts and figures. Temperature phase graph Carbon Dioxide CO2. California University hydro electric. The working system is over 80% efficient as the turbine is its only moving part. If of any assistance I can further add do not use Aluminium if naked heat is to be used as it splits wide open (hence the hot liquid heat sink supply). Complete construction can be had by cut and weld of pipe. Medium grade line pipe easily handles the high pressure up to 12,000 bar. Lesser grade pipe down to plastics are quite suitable for lower pressure. Boiler and Expansion Chamber are end sealed pipe. Turbine making. Split a pipe into four, this creates the turbine vanes. Next weld an odd number of vanes to same size pipe the vanes are cut from. Having done that the turbine runner fits nicely into a pipe twice the diameter of the pipe the vanes were cut from. The compressor is thread etched into extended turbine shaft which itself fits into pipe. A flexi pipe attaches to both end of the compressor and a small amount of water is placed in the flexi pipe so the compressor picks it up creating a seal until the water drops out at the end and back into the flexi pipe. This provides a broken supply delivery but is vertualy friction free. Also of note is no expansion chamber is needed if piping loop is used for cooling. Also of note is no shaft seals are needed as the alternater/generator are sealed in and unafected by the passage of CO2. The whole device may be Aluminum moulded in three parts. First the turbine and compressor shaft as one peice. Next is the casing including boiler, all one part into which the tubine and alternater/generator are placed. Last an end cap is affixed. I have noticed others have been able to place far larger picture, and now I have learnt that is done by slide dragging on the picture when first implaced. I shall set about and draw the complete workings in full and post.

Cheers Peter

Hello Ken, As promised. Sorry but dont know to make bigger. Peter

DAS.jpg

Hello Ken,

Done everything I can think of to get you a bigger picture but now nothing will download. Do yo have email I can send direct.

Cheers Peter

DaS Energy - clicking on the image does open it larger, but it doesn't really tell us much more than my original image in first post tells about that system. Until some of these things have been around awhile there's rarely any independent assessment of their value or details about how they work.