With noon time peak demand the solar, and wind power in normal base loading of thermal power, the batteries cost for backup power is not the justifiable even for smart grids

Dear sir

Battery is used for peak shaving. Also it is very important to use them in renewable energy system. Please see my paper in researchgate site aboutthe hybrid system of wind turbine and photovoltaic

This is what we need to demonstrate with appropriate system studies. Whether, where and when it makes sense or otherwise such an implementation.

Advantages from the user;

1) be independent from the Grid,

2) maintaining the traditional profile while appearing to participate to demand participation initiatives from outside, thanks to an appropriate usage of storage.

1) can factor in the reliability impact

2) can factor in a lot of system services and grid advantages:

-arbitrage (charging at low prices, discharging at high prices)

losses reduction

-deferral of investments

-frequency regulation

-voltage regulation

-generation reserve

which may bring a generous stream of revenues should an ancillary service market be available.

Behind-the-meter batteries (not just for residential but also commercial and industrial and both in stand-alone battery and in combination with PV, are all realities already. They have value not just in enhancing demand profile but for a variety of other reasons from power quality, enhance the value of PV generation, reduce demand charge, etc. That said, if we look at the scale and cost issues - batteries at the wholesale/high voltage end is more effective for improving demand profile, provide ancillary services, reduce congestion, etc. One of the most compact and informative piece I would recommend is Lazard's storage analysis - the latest version is available here: https://www.lazard.com/media/450774/lazards-levelized-cost-of-storage-version-40-vfinal.pdf

Deb Chattopadhyay

Thank you Dr. Chattopadhyay for your answer. I actually was thinking about how the customers could contribute in demand response program. although, considering the capital cost of the behind-the-meter batteries at customer ends and the limited battery life time, this might not be an efficient solution.

Another thing is, the batteries at decentralized level such as at customer end, could provide more expanded services to the power system, comparing to the batteries at ISO or the utility level. however, the economic and operational assessment is required to be carried out by stakeholders and power system operators.

Demand response from the customer end can happen (and is happening a lot in the USA - see for example the FERC reports) without batteries. Customers need battery for managing its own consumption. As for grid services like frequency control, system restart etc - I would argue batteries at transmission level would do this at better scale, cheaper cost and more reliably - much the same way a STATCOM/SVC does the job on voltage control and contingency management side. There is limited experience with batteries for these services but the South Australian experience shows - this is I believe still the largest battery in operation which is connected to the HV end that has avoided power outages by rapidly responding to contingencies and reduced frequency control ancillary services spot prices. Aggregating distributed battery performance which may not even be designed to provide ancillary services in the first place, would be complicated to say the least.

Deb Chattopadhyay

Thank you again, Dr. for the feedback. I've reviewed the LAZARD storage analysis, it is actually very informative. Based on this report, the Batteries have been rarely used for the "demand response program" on the different levels of the power system, in the US or international scale. The only reported demand response application happens in the US, for commercial and industrial customers (either standalone or PV integrated), only for a small percentage. However, the batteries have been substantially applied for bill management in Australia, Ontario and the US at industrial and commercial user ends(behind-the-meter). In residential ends, the main application of batteries is bill management as well. Shifting the demand in low price durations, on the other hand, might cause a ramp-up at other time points. Thus generally the storage application in the smart grid doesn't meet the demand response program, unless for a small percentage for commercial and industrial users in the US.