INGENIEUR Photovoltaic Systems
Industries and researchers have started studying and implementing the new roles of SLB . In Europe , some automotive manufacturers have installed SLBs primarily in different kinds of ESSs , ranging from residential systems to grid-scale solutions . It has been observed that over the different SLB projects worldwide , SLBs are most commonly integrated with Photovoltaic ( PV ) Systems .
Figure 4 : Power variability in grid-scale PV system application
For example , a project utilising both SLB and PV systems is running at University of California ( UC ) Davis campus winery . The system , which is meant as a microgrid , where a total of 360kWh of SLB storage coupled with 230kW of a PV system have been installed . The objective of the project was to further investigate the cost-effectiveness and efficiency of the energy storage solutions in utilising SLB and PV systems . Similarly , SLB packs from 85 used Toyota Camry Hybrid cars have been utilised to provide 85kWh of storage capacity for PV system at Lamar Buffalo Ranch . SLB could be considered for ESSs for low-demand applications such as residential household or power variability in grid-scale PV plants . Other similar projects have been installed across some European countries , US , China and East Asia . However , other regions have yet to implement such projects . The PV and SLB systems combination could be used in different applications such as renewable farming , peak shaving , load levelling , area and frequency regulation , smart grids , microgrids and others ( Strauss 2018 ; Stringer and Jie 2018 ).
Telecommunications
In China , a new regulation has been implemented to ensure that all LiBs from automotive and battery companies will be assessed and considered for potential use as SLB . An agreement has been signed within the framework by China Tower ( the largest operator of telecommunications towers ), battery companies and automotive manufacturers to replace the lead-acid batteries in the backup systems of the base stations with SLB ( Storage 2018 ). Whether using backup systems to keep the vital devices powered , or supporting energyintensive equipment during peak periods , the backup systems could help to provide continuous power supply for smooth operations and increase the quality of power supply , which can be provided by the SLB . China Tower has been testing SLB as replacement for lead-acid batteries in their telecom base stations across China since 2015 . In 2018 , almost 1GWh of SLBs were installed in different applications in China , mostly in base stations as backup power . Although somewhat degraded , SLB could still perform better in terms of life degradation and energy density than leadacid batteries , and they are much cheaper than new LiBs . In addition , SLB is priced at the same level as lead-acid batteries ( around $ 100 / kWh ) in China . The use of SLB is estimated to rise across base station applications on account of growing investment in communication towers across the globe . The fifth-generation ( 5G ) technology has been moving forward with great momentum . It is expected that 5G base stations will have an electricity use rated 2-3 times that of fourthgeneration ( 4G ) base stations , with backup power requirements at least doubled 4G . Therefore , high quality-to-price ratio SLB is an obvious choice as a backup power supply source for 5G base stations .
Other Applications
It is deduced that the most dominating and economical stationary application for SLB is related to stacked services provided by ESS ( i . e ., multiple services at the same time ) ( Bobba et al . 2018 )( Storage 2018 ). Whether it is behind-themeter and / or in-front-of-the-meter , SLB used as ESS could always provide a range of services for the grid . For example , transmission and
72 VOL 85 JANUARY - MARCH 2021