The high level of installation of distributed PVs has again brought the issues of PV-covered buildings and the integration of PV and energy storage systems into the spotlight. Energy storage, once deemed a jargon term for the ubiquitous battery, now encapsulates a completely new industry. 

On 13-14 March 2017, the “All Quality Matters” 2017 Solar Congress and Award Ceremony organized by the TÜV Rheinland Group (TÜV Rheinland) were held in Wuxi, Jiangsu. Jing Zhang, Secretary General of the Special Committee of China Energy Research Society, gave an exclusive interview with SolarBe.com at the venue. She pointed out that the integration of energy storage systems and distributed PV could help users save electricity costs through a time-of-use pricing mechanism. Power suppliers could also provide auxiliary services and increase returns, on the premise that power quality is ensured.

Application of Energy Storage Technology and Policy Support

Jing Zhang told us that the application of energy storage technology varies from country to country and each has its own technological advantage. China possesses very sophisticated and world-leading technology, in terms of the development of lithium ion, lead carbon and flow batteries. China also takes the lead in terms of the integration of energy storage applications and distributed PV. This energy storage system also has great potential in electrical auxiliary services.

The development of energy storage technology, like that of PV, entails the support of government policy. America and Japan were the first countries to issue policies promoting the development of energy storage technology, China followed suit by issuing the Notification of National Energy Administration on Promoting Energy Storage in China’s Northern Regions Auxillary Services Compensating (Market) Mechanisms Trial Project (GNJG[2016]No,164) in June 2016. The Notification encouraged the deployment of energy storage facilities so they can be used for peak load and frequency regulation services at both the supply and user sides. In addition to issuing policies concerning renewable energy on a broader scale, policies on energy storage have also been formulated to encourage further development of these systems. 

Jing Zhang also commented on the opinion that energy storage systems could only survive through government subsidy. She acknowledged that policy plays an essential part in facilitating the application of energy storage, and in some cases, subsidy is all that sustains a project. However, policy support is more than subsidy, as the market mechanism also plays a part. After it comes to fruition, an energy storage system can also be exposed to competition in the power market.

Integrating Energy Storage with Distributed PV 

In some parts of China, the cost of PV generated power has become equal to that of coal generated power on the consumer side. Its cost per kilowatt-hour is even lower than that of commercial power. The owners of distributed PV are now beginning to reap the benefits. According to Jing Zhang, more could be gained from the energy storage system via the time-of-use pricing mechanism when distributed PV are integrated with the energy storage system. She suggested that the time-of-use pricing mechanism has not yet been fully implemented in some areas.

Jing Zhang is not alone in questioning the full utilisation of the time-of-use pricing mechanism. On August 23, 2016, Mingzhu Dong, who announced her plan of acquiring YinLong at the press conference, also stated that the lithium titanate battery, which has a service life of 30 years, is certainly able to serve as an emergency power supply for large buildings, hospitals and high speed trains. A large cost-saving could be achieved when the battery is charged if the electricity price is low and the battery is discharged at peak hours. Through proper implementation, power suppliers could take advantage of a market worth trillions.

She also explained that it is only economical to install an energy storage system when the spread between the peak and the valley is RMB0.75/KWh, because the cost of deploying the system is still high and its service life still cannot be guaranteed. The full potential power of the energy storage system could be realised when the spread is above 1 Yuan.

Quality Precedes All and All Quality Matters

High quality and security are essential in energy storage systems. Jing Zhang emphasised that security entails not only the focus of research personnel and system suppliers, but also of standards and accreditation. The “All Quality Matters” Congress organised by TÜV Rheinland is a significant event. With its focus on quality and security, it has helped strengthen the security and quality awareness of all the enterprises present.

At the beginning of 2012, the Quality Development Outline (2011-2020) was issued by the State Council. In June 2015 it also issued Made in China 2025. These documents were intended to rebrand China as a nation that values quality. Jing Zhang said that we must adhere to the principle of “Quality Precedes All and All Quality Matters”. Although energy storage is still at its early stage of development, quality and security should still be top priorities for ensuring its future. Third-party institutions could also be important in terms of quality assurance.