Why storage business cases depend on weather

Dr Björn Peters will be speaking at the Energy Storage World Forum in Berlin this year. Pic: Energy Storage World Forum.

Dr Björn Peters will be speaking at the Energy Storage World Forum in Berlin this year. Pic: Energy Storage World Forum.

By Jason Deign

The case for implementing storage in electricity networks should be based on long-term weather analyses, attendees at the Energy Storage World Forum will hear.

Including weather patterns as one of the main variables in a business case analysis will help show niches where storage “makes a lot of sense,” said Dr Björn Peters, who will be speaking on the topic at the Forum in Berlin this May.

For off-grid mining operations in hot climates, for example, “there might be a very good business case for solar storage” compared to diesel.

Within grids, meanwhile, storage can offer value in helping to balance out short-term fluctuations in intermittent renewable energy.

However, Peters’ research is worrying for policy makers who hope to rely completely on intermittent renewable energy generation to reach European carbon reduction targets. 
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The second-life threat to non-lithium batteries

Second-hand batteries from electric vehicles such as buses could drastically cut the price of lithium-ion-based storage, research predicts. Photo: www.animam.photography

Second-hand batteries from electric vehicles such as buses could drastically cut the price of lithium-ion-based storage, research predicts. Photo: www.animam.photography

By Jason Deign

Lithium-ion’s potential to dominate the stationary storage battery sector may be stronger than previously thought, according to the implications of a new study.

Research published last week by the analyst firm Bloomberg New Energy Finance (BNEF) shows a glut of second-hand lithium-ion (Li-ion) batteries from the auto industry could cut battery storage costs significantly.

By 2018, says Used EV batteries for stationary storage: second-life supply & costs, the cost of repurposing batteries for second-life applications could go down to as little as USD$49 per kWh.

This compares to a cost of roughly $300 per kWh for new batteries at the moment, and $160 for lowest-cost battery chemistries such as the zinc hybrid cathode technology being commercialised by Eos Energy Storage.

Given that BNEF expects around 10GWh of capacity from used electric vehicle batteries to be entering into the stationary storage market by 2025, second-life applications could deal a real blow to the prospects for non-Li-ion chemistries.
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Batteries aren’t worth it to store wind

Wind farm

Batteries won’t work for wind. Pic courtesy of Gamesa.

Stanford University scientists have worked out that from an energy point of view it doesn’t make sense to store wind power in batteries. The energy cost of building the batteries is more than the value of the power that would be lost through curtailment.

The researchers compared the finding to the cost of storing cash in a safe, noting that it would not be worth paying USD$100 to store a $10 watch. Since wind power is so cheap, buying batteries to store the excess energy it produces is not worth the effort. This is not the case with photovoltaic energy, which costs more to produce in the first place.

Nor does it apply to other forms of energy storage: storing excess wind power in pumped hydro reserves, for example, is still energetically economical. The authors note that the value of batteries for excess wind energy storage could be improved by increasing their cycle life.

To be worth the investment for wind energy storage, batteries would have to last between 10,000 and 18,000 cycles, they say.

Solar storage market to reach $2.8bn

Corporations in the solar and energy storage sectors have long dreamed of combining the two technologies to differentiate products and defend margins. This match shows promise, yielding a USD$2.8bn market over the next five years, according to Lux Research.

Grid-tied solar installations will comprise 675MW, or nearly 95% of a combined 711MW market, while off-grid applications including telecom power claim the remaining 5%. While the off-grid market enjoys higher profit margins, the much larger addressable market for grid-tied systems means they dominate the solar and energy storage market.

“Developers are pushing packaged solar and storage systems in order to stand out as value-adding leaders, but not all benefit equally,” said Steven Minnihan, Lux Research senior analyst and a co-author of the report.

“Residential energy storage will see a boost in adoption due to solar, but the addition of storage will barely move the needle for solar players, driving a paltry 1% increase in global PV sales.”

Opinion: a plea for joined-up thinking

This article was previously published in Marine Renewable Energy.

It seemed an innocent enough story at the time. We ran an article in which Sven Teske, director of Greenpeace International’s Renewable Energy Campaign, sounded a note of caution about Germany’s growing love affair with residential energy storage.

Germany had recently introduced incentives for battery storage that will largely encourage homeowners to store some of the power they get from roof-mounted solar panels. No problem at all with that. Only, as Teske pointed out, if homeowners are hoping to get rid of their electricity bills altogether they are in for an upset when the gloomy German winter sets in.

A residential battery pack big enough to last all winter is simply too costly to be worth it. That is why German communities might want to look at energy storage on a larger scale, believes Teske. Not everyone seems to agree, however. The article sparked spirited email and Twitter comments from observers in the energy storage sector.

System developer Younicos waded in with the notion that batteries could support solar power in the summer and wind in the winter. Leaving aside the validity or otherwise of the ideas under discussion, the episode was an instructive one for renewable energy professionals because it highlighted a much more significant issue: we don’t know where we are going.

Incentives and regulatory frameworks for renewable energy vary greatly between countries and technologies. They change radically over time, too. Thus five years ago the big opportunities for wind energy, for example, used to be onshore in places such as Spain and Germany. Now they are increasingly offshore and in countries such as the UK and France.

Much has been written about how this pick-and-choose approach to regulation damages the prospects of particular renewable energy markets. As some of these markets (notably wind and solar) start to mature, though, further cracks are starting to appear.

Take Germany: compared to most European nations, the country deserves full marks for its support for renewables, but now it is churning out significant amounts of green power it is becoming apparent that more is needed. Nobody appears to have given much thought to renewable energy surpluses, for example.

Right now, there are indications Germany’s neighbours are already losing patience with being used as dumping grounds for spare generation capacity. And it seems the country’s current support for residential battery storage is driven as much as anything by a desire to keep further renewable power, generated by homeowners, from overloading the grid.

You could argue that part of this situation is due to Germany’s late implementation of smart grid technology, which could potentially give the power network added flexibility to absorb renewable power. That may be a simplistic view, however.

More likely, each country would need to implement a combination of smart grid and energy storage technologies to be able to maximise the integration of renewable energy. Nobody seems to be thinking about how to do this.

At the European level, meanwhile, somebody should be thinking about cross-border power connections and the creation of a supergrid to ship renewable energy across the continent. Nobody appears to be doing this, either.

Finally, someone should be making sure the European strategy and objectives are closely linked to the strategy and capabilities of each country. Plenty of winter wind power coming off the North Sea? Hey, send it off to the Mediterranean. Scandinavia sweltering in a heat wave? Use some of Germany’s excess solar power to cool things down. Simple. Yet find the person working on it.

All of this poses a problem for renewable energy plant developers and operators because it means they are essentially being asked to stake heavy investments on markets which are poorly thought out and liable to change. They are also in many cases being asked to produce energy without much idea of where that energy could or should end up.

Hence ridiculous concepts such as curtailment, which essentially amounts to getting someone to invest large amounts in a plant and then forcing them to switch it off.

This is just a guess, but one suspects that with the right combination of Europe-wide smart grid, supergrid and energy storage technology, curtailment would be virtually irrelevant, as would many national infrastructure investments. Of course, the likelihood of European nations collaborating at this level is pretty far-fetched.

But there is no reason why Europe’s clean-tech industries could not lead the way. At the moment there are plenty of bodies and events for industries such as wind, solar, tidal, wave, smart grid, supergrid and energy storage, not to mention those associated with traditional power generation.

But where are the cross-links between these? Where are the pan-technology strategy sessions and planning summits? Where is the meeting of minds? This is something the energy sector is crying out for, so let us get to work on it… if only so journalists can print unassuming stories about battery storage without inviting a barrage of dissenting views.

Blowing in the right direction

Wind farm (pic courtesy of Gamesa).

Wind farm (pic courtesy of Gamesa).

A week after the suggestion by the Massachusetts Institute of Technology that offshore turbines could store their excess energy through an underwater pumped hydro mechanism comes the news that a wind institute will be considering what it describes as “next-generation energy storage.” While no further details have been given, the storage project will be part of programme of research at Texas Tech University’s newly created the National Wind Institute (NWI).

Aiming to better support interdisciplinary research and educational opportunities in wind science, engineering and energy, and announced on May 6 at the American Wind Energy Association WINDPOWER 2013 Conference and Exhibition in Chicago, the NWI is an amalgamation of the former Wind Science and Engineering research centre and the Texas Wind Energy Institute.

Another sign that wind is waking up to the need for energy storage is the first reported purchase of GE’s 2.5-120W wind turbines. As well as an impressive suite of predictive and management technologies, the new model (named “Brilliant” by the company) is the first to have on-board battery energy storage, in the shape of GE’s Durathon units. Invenergy has ordered three machines as part of an 86-turbine deal with GE for its Mills County, Texas, wind farm.

Graphene advance for Li-ion batteries

Graphene has been cited as the saviour of lithium-ion rechargeable batteries for a while now. As an incredibly thin substance, it can massively increase the surface area of an electrode and thus increase the energy density of a battery. The big snag, however, is what researchers call pulverisation: the damage that these very flimsy nanostructured electrodes incur during recharging cycles.

Now, though, a team at the University of Science and Technology in China has managed to prevent the issue of pulverisation by using atom-thick cobalt oxide.

NY-BEST to stage microgrid event

The New York Battery and Energy Storage Technology Consortium (NY-BEST) is holding a one-day forum on energy storage and microgrids at the Pace University New York City Campus, on June 11. The cost is USD$100 for NY-BEST members, $150 for non-members and $50 for students, and you can register now online.