While Solar PV module Price are declining trend due to falling cost of PV Module, Developers are exploring various other option in BOS design optimization by Moving Toward 1500Vdc Solar PV System to further reduced overall system cost in this article we are discussing the PV system cost optimization through adoption of 1500Vdc Solar PV system in place of the conventional 1000Vdc Solar PV system.
The advantage and challenges in the 1500Vdc system are highlighted through of one of the system design case study of 3MWp Fixed tilt Ground-mounted Solar Power project.
Indian Solar market has become highly sensitive in respect of price bid solar electricity is being offered at Rs.2.44/KWh.
Achieving such as the solar cost of power generation has been possible through the financial and engineering optimization of the project cost. Statics know that currently PV module price of 36-Cents/Watt. From the earlier price of about 42 cents/watt earlier back. Similarly, there has been a slide decline in the balance of system price.
For example, inverter price come down from 0.1 cents/watt to about 0.8 cents/watt from 2015-2017.
It’s expected that module price will remain stable and not face significant price decline, however, the decline in next 3-year overall system cost reduction trends is likely to continue. This will put pressure on price optimization in BOS design.
Technical and Finacial consideration for 1500Vdc Solar PV System
Moving Toward 1500Vdc Solar PV System has not only reduced but also leads to overall improved system efficiency. Operating the solar PV string at a higher voltage to leads to reduce dc side losses and will improve the generation by about 2%. The dc side losses reduction is due to cable length as well as diameter. This will reduce ohmic losses at the 1500Vdc system. Design the 1500Vdc system requires not only the increase PV array size but the rest of the dc side equipment such as SCB, DC switches, Cables, PV module to compatible to operate at 1500Vdc.
The overall system design is 1500Vdc inverter whose operating dc voltage range 800-1300 V.
The typical specification of 1500Vdc as compared to the 1000Vdc sungrow inverter.
|Min. PV input voltage||800 V / 840V||520 V / 540 V|
|Vmpp||800 – 1300 V||460 – 850 V|
|Nominal AC voltage||550 V||315 V|
The higher efficiency in the inverter is achieved due to the reduced current flow of in IGBTs. There is cost saving in the AC side as well as to reduced transformer losses as we can see 1500Vdc inverter specification the output voltage of inverter increases from 315-550Vac. The Reduced the current flow off by almost 70% and lead to overall reduced ac losses in transformer also.
The conducted PVsyst analysis for both systems design and compared the dc side as well as losses highlighted by the graph.
While the market is set to 1500Vdc system design various manufacturer have with their inverter operating at 1500Vdc. Some of this manufacturer whose are offering inverter such as Delta, Sungrow, ABB, etc. the overall efficiency of the 1500Vdc system is offered by the companies is higher than the 1000Vdc system. The operating efficiency temperature 55°C is also better as compared to the typical 1000Vdc system. This is suitable to climate condition of India.
While we are moving toward 1500Vdc Solar PV System are a challenge in term of availability of other components to capable at the 1500Vdc system. This requires the other industry partner such as MC4 Connector, SMB, PV module, Dc switches and other accessories.
Presently due to the low volume of the BOS component operating at 1500Vdc so costing is higher as compared to 1000Vdc showing in below graph.