The year in solar, part IV: More storage and hydrogen advances as solar just kept getting cheaper


With lithium-ion battery storage facilities being deployed at grid scale in the U.S. and Australia, the last three months of the year saw significant advances in other forms of large scale storage technologies, from pumped hydro to power-to-gas to thermal solutions such as cryogenic and molten salt storage.

In November, we took a look back at the storage advances made this year and suggested the claims of the natural gas industry to be necessary as a bridge to a fully renewable energy grid may prove wide of the mark.

And there were other advances in storage tech reported with scientists in Sweden and Slovenia developing an aluminum battery which replaced graphene in the cathode with organic, nanostructured anthraquinone. The developers say it boasted twice the energy density of conventional aluminum devices, helping bridge the gap on lithium-ion.

Carbon dioxide battery

Performance and energy densities up to seven times higher than lithium-ion devices could be offered by lithium-CO2 devices if only stability problems could be overcome, and scientists at the University of Illinois at Chicago claim to have done just that, with a device which remained stable over 500 cycles, even if the researchers used theoretical calculations to describe the battery’s reversible operation.

It isn’t just storage which has hogged the R&D headlines of late, with scientists from Barcelona and Madrid developing a cheap, 2-D layer of microspheres which they say can lower the daytime temperature of a silicon wafer 14-19 degrees Celsius by radiative cooling.

With hydrogen making gains as a storage solution for renewable energy, the element’s use as a fuel has also been highlighted recently with French fossil fuel company Engie developing a hydrogen engine to power the huge, building-sized haulage trucks operated by miner Anglo American. The first vehicles are set to be tested in South Africa in the new year.

Hydrogen bus transport

And the hydrogen transport revolution could be coming in a more recognizable form in Europe soon, with long distance coach service route planner Flixbus announcing an intent to trial hydrogen vehicles on some of its European network. Now it will just have to persuade the regional bus operators which have adopted its livid green Flixbus livery – and which actually own the coaches.

It has been a notable period for big solar tenders in recent weeks, not least the 900 MW fifth phase of the 5 GW Mohammed bin Rashid Al Maktoum Solar Park in Dubai. It took a while for the Dubai Water and Electricity Authority to confirm but Saudi developer ACWA Power did in fact lodge the lowest bid, offering to sell its power for $0.016953/kWh, and thus falling only marginally short of the world record low price established by French rival Akuo in Portugal’s first capacity auction, in August.

That was even lower than the $0.027-0.036 reported by analysts Bloomberg New Energy Finance as the best average price achieved in auctions held in India, Chile and Australia as the business intelligence firm reported solar had reached price parity with wholesale electric prices in California, China and parts of Europe.

Hoist by their own petard

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So we probably weren’t too surprised to learn the average price premium paid to renewable energy projects on top of the wholesale power price in Denmark had fallen 30% in the nation’s latest capacity auction, down from last year’s exercise. The pitfalls of the runaway success of cheap clean energy were laid bare when the delighted minister responsible mused that perhaps the authorities were devoting too much public funding to solar and wind.

The formula for those steepling price falls shows little sign of letting up either, with analysts at PV InfoLink recently warning lower-than-expected PV module demand in the current quarter had forced solar manufacturers who have ramped up huge production operations this year to make “record-low quotes” to customers to keep stock moving.

The other side of the coin in the race to price parity with fossil fuel electricity is the ever-rising efficiency levels offered by panel innovation. Our former pv magazine publisher Karl-Heinz Remmers predicted modules will continue to press down on the levelized cost of solar energy by offering 20% more electric output for 25% less cost by the second quarter of 2021.


Elsewhere in the headlines, we heard about the plans of Swiss utility Axpo to angle 2 MW of solar module generation capacity at a steepest inclination of 77 degrees on the vertical wall of the Muttsee reservoir in the Apline canton of Glarus, 2,500m above sea-level. And we also discovered talk of rare earth usage in the solar and storage industry is largely a myth. While materials such as tellurium, cadmium and indium may be none-too-pleasant, they do not qualify as rare earths, according to the French Environment and Energy Management Agency.

Raw material sourcing

As part of pv magazine’s global UP sustainability initiative, we will focus on raw material sourcing in the energy storage industry in Q1, 2020. You can look forward to reading about lithium extraction in Chile, cobalt from the Congo and the development of raw material recycling. Contact for more information or to jump on board!

After a merciful cessation of legal hostilities in the Q-Cells-against-the-world patent infringement cases opened by the Korean manufacturer this year, the judge responsible for the U.S. litigation granted opponent Jinko’s request for a summary decision in the case, with the Chinese firm stating its confidence the dispute – at least on U.S. soil – would be settled in its favor.

And we were recently reminded of a similarly acrimonious dispute as Israeli inverter maker SolarEdge filed another three patent infringement claims against rival Huawei in China, having taken similar action in Germany in the summer of last year. That news arrived in early October and, by late last month the German court handling the original cases had ruled in favor of Huawei in the first case, deferring a decision on the other claims. SolarEdge responded by instantly stating its intention to appeal.

Up on the roof

We can’t finish the final installment of our year in solar review without mentioning Tesla once more – even though we know how acutely Elon Musk dislikes being in the media spotlight.

The media-shy CEO announced the third iteration of his Solar Roof PV tile in October, after the previous two attempts failed to set the world on fire and, even though his headline claim that it could be manufactured for $1.99/W may actually prove to be nearer $2.83/W – and $4.04 without the Investment Tax Credit – that is still a substantial discount on versions one and two.

Read parts I, II, and III to complete the picture.

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