PVTIME - As of the end of 2019, the cumulative installed capacity of grid-connected photovoltaics in China reached 204.68GW. From 2017-2019, China added 53GW, 45GW, and 30.2GW in capacity respectively, completing the installation goals outlined in the “13th Five-Year Plan” ahead of schedule.
At the same
time, cost reductions and efficiency improvements along the photovoltaic
industry chain also advanced at a similar pace. Prior to 2016, the conversion
efficiency of PV modules was improving at a rate of approximately 0.3% per
year, equating to about a 5W per year increase in mainstream 60 cell modules.
Starting from the 2017’s yearend, it seems as if a new conversion efficiency
record is announced by a company every couple of months.
With the
“13th Five-Year Plan” concluding in 2020, Wang Jixue of China
Renewable Energy Engineering Institute’s Renewable Energy Division expressed
his outlook for the “14th Five-Year Plan” during the broadcast of
the Fifth Century Photovoltaic Conference organized by CNE Media and PVTIME.
“Beginning
from the midway mark of the “13th Five-Year Plan”, the technical
aspects of China’s photovoltaic industry began improving greatly. This steady
improvement is inseparable from the support of national policies which resulted
in the promotion of market development as well as industrial upgrading.
Presently,
China is at the forefront of the world’s large scale solar cell production. If
China is to maintain this lead for the next 5 to 10 years, it needs to continue
to push for technological breakthroughs, prepare to adapt to emerging
technologies, and strengthen the protection of its supply chain’s intellectual
property.
Additionally,
aside from focusing on technical improvements on the manufacturing end, China
also needs to place emphasis on the support capacity of PV power stations, and
promote the adoption of solar energy as the primary energy source by enhancing solar
generated electricity’s price competitiveness.”
Preferred 166mm wafers and the adoption of
large size wafers down the road
In recent
years, in order to obtain higher module power output and production cost
reductions, companies have been incorporating 158.75mm, 161.7mm, 163mm, 166mm,
and 210mm large size silicon wafers into their manufacturing operations. According
to CPIA data, 156.75mm wafers will slowly fade out of the market in the next
five years, and the proportion of 160-166mm wafers will gradually increase.
On the
topic of large scale PV power stations’ future module section and developmental
direction, Technical Director of Seraphim, Jin Peng said, “the increasing of
wafer sizes is a relatively recognized developmental trend for the industry
presently. Our analysis of 166mm wafers shows that its advantages offer it a
very promising future in the market.”
It is
understood that the industry is becoming more and more receptive of
multi-busbar technology’s contribution on increasing module efficiency. 9BB
increases the light receiving area of the cell and raises its overall
efficiency by more than 40% thanks to the reduction of the shielding of light
along the solder strips. At the same time, when combined with half cell
technology, the cell’s power loss is reduced as well.
Jin Peng
went on to say, “MBB + half cell is a combination widely used at this time.
Additionally, when combined with large size wafers, the improvement in power is
very significant. Currently, about 75% of the modules in the market are
bifacial, and are able to generate anywhere from 10-30% in revenue under
current production costs.
In the
future, more and more power stations will be using bifacial modules, which will
reduce land usage as well. Taking a 100MW PV system as an example, a
considerable reduction of 1.2% in land usage can be achieved.”
According
to IHS Markit’s 1500V Global PV Market Analysis Report, the combined scale of
1500V PV power stations will exceed 100GW in 2020 and high-voltage products
have become the mainstream solution for the global PV market.
“Most of
our module systems have switched to the 1500V system design. The high-voltage
module system design is more flexible and reduces capital investment,
installation, and maintenance costs of equipment such as cables, junction
boxes, and inverters. According to Seraphim’s data, the combination of large
size wafer and MBB will be the preferred module design for large scale power
station application.” Jin Peng added.
Will 18Xmm be the optimal wafer size in the
future?
Regarding
the development trend of large size wafer, General Manager of Shuri Energy
Zhang Zhiyu, shared his point view from the technical level, “as manufacturing
costs become lower and lower, more savings will become achievable for power
stations that select larger modules.
While
larger modules become 20% bigger, the framing, bracket, packaging, and other
costs only increases by 10%, but can brings about approximately 40% in savings
to the power station. Additionally, due to the nature of the junction boxes,
they are able to support the larger modules while manufacturing costs remain
unchanged.”
Theoretical
data shows that, the larger the module, the higher the power output, which
leads to lower costs. Is this really the case?
“Transportation
is one of the biggest restraints in the application of larger modules.
Maintaining the optimal arrangement of components in shipping containers can
control and reduce the costs associated with transportation.
According
to calculations, in order to maximize the use of shipping containers, 1.2m is
the optimal width for a module, and the maximum size of the wafer is then 18Xmm.
I believe that in the future, PV power stations will usher in the 600W as the
larger size modules become more mainstream.” Zhang Zhiyu added.
“Front Runner” and “Grid Parity Demonstrative
Project” leaders: future cost reductions in PV power stations will come from
the construction side.
The
Baicheng Front Runner Project is a typical example of China’s current PV
technology development progress. It adopts large size bifacial modules, 1500V
systems, adjustable tracking brackets, and flexible DC to AC control, reducing
investment costs while ensuring the stability of income.
Currently,
the per watt construction cost of PV power stations is far greater than that of
manufacturing it. The cost per watt in modules is about 1.5 yuan, while the cost
of BOS for PV power stations has exceeded 1.5 yuan. In this regard, Zhang Zhiyu
said, “in the future, the focus of cost reduction for PV power stations is not
on module production, but on the construction end.”
Regarding
the design optimization of future power stations, Meng Fanhui of POWERCHINA
JiLin Electric Engineering Co., Ltd. said, “Choosing the optimal capacity ratio
is crucial to a project’s profitability. Also, module tilt angle optimization
can not only increase power generation, but also reduce investment costs
associated with the supporting structure. The application of a 1500V high
voltage system can also reduce DC side costs by about 2%.”
Currently,
there are many subarray units of competitive parity projects exceeding 3MW in
China. According to previous calculations, large square 3MW arrays can reduce
investment costs by 1.5% compared to the original 1MW arrays.
“Different
layouts of the same square array can bring about cost difference in aluminum
alloy cable by more than 10%. Application of new materials such as galvanized
aluminum will also reduce mounting bracket costs.” Meng Fanhui said.
Gu Binfeng,
Project Manager of Shanghai Branch of TÜV SÜD Certification & Inspection
China Co., Ltd., said, “from our experience with previous projects, the
influence of electricity price policy is very important to PV power stations. Whether
or not the power station is included in the national renewable energy subsidy
catalogue, and the deadline requirement for its grid connection determines the subsidy
price it enjoys.
The
attenuation rate of photovoltaic modules directly affects the income of the
power station. In addition, other factors such as the performance, seasons,
temperature, and weather are also critical factors which can affect the power station’s
operation."
