Solar+storage, solar+storage, solar+storage: the greatest on, off and on again relationship since Ross and Rachel from Friends returned disguised in new fancy dress this week as Chinese thin-film extra (sitting in the background, chatting to nobody in particular) Hanergy unveiled its new "zero charge" electric vehicle in Beijing.
The four prototype models on show follow in the track marks of Toyotas solar-integrated Prius hybrid EV in that they combine thin-film solar cells with a lithium-ion battery to deliver zero emission and zero charge driving.
The cells have a conversion rate of 31.6% and can generate some 8-10kWh of energy per day enough for around 80 km distance based on solar alone. This "zero charge" feature, the company says, will help do away with the problem of range anxiety, with vehicles no longer needing to rely on charging stations for short and medium-distance car trips.
In the cases of weak sunlight or long-distance travel, drivers can recharge the lithium-ion batteries using traditional EV charging stations, to a maximum travel capacity of 350km.
"Breaking the bottleneck of poor practicality of previous solar-powered vehicles, the four launched by Hanergy are the first full thin-film solar power vehicles that can be commercialized, redefining new energy vehicles," Hanergy said in a statement.
A great deal of the week just gone was mercifully free of that dreaded Brexit word, but that did not mean Europe was all of a sudden sweetness and light. Indeed, trade body SolarPower Europe took advantage of this relative lull to call on the European Commission to end trade measures on Chinese PV, claiming them to be counterproductive and serving to negatively impact the European solar landscape.
"This is an overwhelming show of support from organizations across the EU working in solar," said SolarPower Europe CEO, James Watson. "The measures have been in place for more than three years without any real benefit to the European solar industry."
The crux of the argument, outlined within the letter, is that these measures are making solar more expensive in Europe, which is affecting the entire value chain. This in turn is affecting the competitiveness of solar energy generation and is prolonging financial support from European governments.
Additionally, the letter points out, hindering the competitiveness of solar energy is contrary to the goal of the EU to combat climate change and reduce carbon emissions. "European jobs, GVA, climate change policy, consumer interest and manufacturing interests are all being undermined by the trade defense measures," reads the letter.
Nigeria revs its engine
More positive news came out of Africa this week as the Nigerian Bulk Electricity Trading Plc (BNET) confirmed that it had signed PPAs for as much as 975 MW of solar PV with a number of developers putting the country well on the way towards hitting its 1 GW installation target.
The government-owned NBET has struck deals with 12 developers for the 975 MW capacity, which sets out PPAs for solar power of $0.115/kWh, and is the first step along a proposed $1 billion investment push into the Nigerian solar market outlined for the next five years.
"We are delighted that the federal ministry of power is pushing ahead with its solar energy policy," said Pan Africa Solar CEO Marcus Heal. "This tariff has been achieved through harnessing lower construction and lower solar panel prices and the commitment of the projects lender."
China growth shaping inverters
Whether the figure is 15.1 GW, 18.6 GW or somewhere in between, the message is the same: Chinas 2015 solar PV growth broke all previous records, but brought with it problems, not least issues surrounding grid curtailment and late subsidy payments.
Faced with these difficulties, the government and the industry are turning their attentions to more distributed avenues for solar growth and in turn are altering the makeup of the Chinese inverter landscape, finds IHS.
Last year Chinese inverter shipments hit a record 22.8 GW, of which 7.5 GW were write-down and channel inventory. The excess figure more inverters than GW connected means that all inverters will be installed but not necessarily allowed to connect, at least not immediately.
As market consolidation deepens (the top six Chinese suppliers Huawei, Sungrow, TBEA, Sineng, Chint and KStar took 95% of the market), the product mix is changing more quickly, with three-phase low power inverters (less than 99 kW) becoming the second-largest inverter product type after central inverters. Huawei in particular has been proactive in using such inverters in large-scale solar farms.
SunPower eyes islands
Last week France announced the details of its solar tender amid muted, but appreciable, fanfare. This week, U.S. clean energy developer SunPower swooped in and snapped up 76% of the going capacity for Frances solar+storage island tender.
SunPower was awarded 27 out of a total 33 tenders. This accounts for 76% of the process and will see the company supply 39.1 MW of solar and storage technology to Frances ZNI. This is made up of 20.7 MW of its modules, and the development of five projects with a combined capacity of 18.4 MW including battery storage.
Three of these projects will be located on Corsica and are being developed in partnership with Corsica Sole. The other two are on Martinique and Guadeloupe, respectively, and all are expected to be completed by mid-2019.
With an efficiency increase of 3% in 2009 to up to 22% today, perovskite semiconductors have attracted the attention of PV researchers around the globe. A team from Molecular Foundry and the Joint Center for Artificial Photosynthesis at Berkeley Lab have deployed atomic force microscopy to reveal the "bumpy surface" of a perovskite solar cell, indicating that efficiencies vary widely within the cell dependent on the nature of its surface.
Investigating perovskite solar cells at the nanoscale, the researchers discovered that the cell surface is composed of grains around 200 nanometers. At the nanoscale, the research also revealed that each grain itself has multi-angled facets – like the faces of a gemstone, Berkeley Lab explains in a press release.
The photocurrent generation, and therefore conversion efficiency, of the different facets varies wildly, approaching 31% at the highest end, down to very low efficiency on others. The facets behave like "billions of tiny solar cells, all connected in parallel," the Berkeley press release elaborates. With current flowing from to the good to the bad cell, the overall efficiency of the material is reduced.