Smart grid, battery storage, and your electricity bill

24 Oct 2018

Integration of smart grid technologies at the household level will ultimately help manage consumption and ensure least operating costs, lowering power bills

Smart grids
Addition of IT technologies to the conventional power grid provides extra features that can be described as SMART - Self-Monitoring, Analysis and Reporting Technology.

Smart grid is a relatively new term, but is a concept that is here to stay, like smart phones and smart cards. To us, as consumers, power distribution is the most crucial aspect of a smart electricity system since we all, as direct beneficiaries, are a part of it.

A smart grid is essentially a bouquet of technologies that integrates electrical power systems with Information Technology (IT) and automation for overall improvement in the functioning and service delivery. Addition of these technologies to the conventional power grid (existing system of thermal power plants, overhead lines, substations, transformers, electricity connections and meters) provides extra features that can be best described as SMART - Self-Monitoring, Analysis and Reporting Technology. The analysis of real-time data, whether it is from the electrical apparatus in substations or from the appliances of a household, and its application towards performance improvement is the basic action taking place in a smart grid. The customer-centric nature and consumer involvement is the very essence of a smart grid. Extension and integration of smart grid technologies at the household level will ultimately bring reductions in power bills by managing consumption and ensuring least operating costs. One of the ways this would be done is replacement of existing digital electricity meters with smart meters that will allow customers to participate in Demand Response (DR), another smart grid technology, and earn incentives for shifting their demand to a time when the electricity provider’s system has lesser load.

A smart grid system will also have clean power generators like those based on renewable sources of energy that would work in synergy with other sophisticated technologies.

Battery storage

One such technology is Battery Energy Storage Systems (BESS). A smart grid encourages integration of more and more power from renewable energy based sources. However, as sunlight and wind are intermittent during the day, power generation from these sources would pose some operational challenges. Hence, a smoothening mechanism is required to ensure reliable and quality power supply to consumers. The BESS will essentially absorb excess power from the sun during solar hours (if demand is less during that period) and store it to supply during peak demand periods, in a way restoring balance in the system by time-shifting of energy.

Installing BESS at the local substation level, from where supply goes to individual households, is an option for successful implementation of a smart distribution grid. These installations will also help reduce the stress on local transformers and enhance their operational life by supplying energy stored in the battery during periods of high electricity demand, thus reducing load on the transformers. Research is underway to find the optimal size of such batteries and to find the best strategies to operate them for various applications at the distribution network level. One such unique initiative, called UI-ASSIST, has been launched recently by the governments of India and the United States of America.

The US-India Collaborative for Smart Distribution System with Storage (UI-ASSIST) is a multi-partner research project that focuses on research, development, demonstration and pilot-scale implementation of Battery Energy Storage Systems (BESSs) at the distribution grid level for various applications under the smart grid paradigm. TERI is one of the Indian partner institutes in this consortium-based project jointly funded by the US Department of Energy (DoE) and the Department of Science and Technology of the Government of India.

Under this project, TERI will install lithium-ion battery systems in large-sized containers (such as those commonly found in ship yards) at distribution transformers at three sites in the area of supply of BSES Rajdhani Power Limited (BRPL) in New Delhi. The aim is to ensure reliable and quality power supply to consumers belonging to three different categories: - gated residential colonies, housing apartments and institutional campuses.

The systems will operate so as to avoid overloading of transformers, which is very common in the Capital, particularly in summer nights due to the load caused by use of large number of air-conditioners. TERI has conducted field surveys in these locations to gauge the willingness of consumers to adopt BESS and to assess the feasibility of installing the system at these sites. The challenges in installing the system amidst physical space constraints are one of the key observations that have emerged from this exercise so far. Research is underway to find the correct capacity of such batteries and their control strategy. TERI has already progressed with the battery sizing exercise and collection and analysis of data on the network so as to design the systems and install them. This is a five year long project that will showcase the impact of BESS integration at the distribution system. The wide spectrum of distribution level consumers covered and the type of BESS application that will be implemented on field make this project unique.

Energy management
Energy storage