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The case for flexible interconnection featuring our successful Flexible Interconnect Capacity Solution (FICS) project with AVANGRID
Smarter Grid Solutions was proud to be brought in as the DERMS solution provider in the Flexible Interconnect Capacity Solution (FICS) REV demonstration project with RG&E / AVANGRID in New York State. The project features our flagship Strata Grid DERMS (distributed energy resource management system) product and highlights how flexible interconnections help connect much more clean DER (distributed energy resources) onto the grid both cheaper and faster.
Historical Note
When the modern power system was brought into being, one fundamental assumption was that power would flow in one direction from thermally efficient centralized power stations through high voltage transmission then lower voltage distribution grids and through voltage step-down substations to the end user.
The system works so that there is always a well understood and stable relationship between upstream generation and downstream demand such that all lines, cables and transformers are able to cope with the maximum downstream demand.
Distributed Generation
With rising concerns over climate change and corresponding energy technological advances, the traditional electrical grid model has been shaken up. Instead of our electrical power coming from central generation locations, there are now increasingly distributed generation sources such as wind turbines, solar PV and batteries located in the distribution system closer to the final consumer demand. These new and green power sources are now distributed across the electrical grid. This sounds like a good thing, after all, don’t we want more of our energy to come from green sources?
Problem
New York State (NYS) has very ambitious targets to source 70% of it’s electricity from clean sources by 2030. This will be a combination of large and smaller scale renewable generation. NYS also has leading programs to modernize the grid and reform its energy markets.
The New York power system was also primarily designed for power to flow in one direction. But now, local imbalances between distributed solar power production and demand change this fundamental balance. That original grid design did not foresee surplus local energy flowing back up into the distribution system. That reverse flow, or backfeed, can cause real technical issues such as transformers overheating due to thermal constraints. Unwanted and dangerous voltage rises are another consequence of this backfeed phenomena.
Utilities must prioritize system integrity and safety over new renewable energy production, although state goals and incentives are aiming for both. So how should the needs of grid safety and renewable generation goals be balanced? The market has shifted significantly, and solar PV equipment is cheaper for project developers to buy and install. But those projects need to apply for and pay to interconnect to the grid. The host utility does a thorough and conservative analysis of the limits of the relevant grid circuits and equipment. But keep in mind that they are thinking and planning for a worst-case scenario – maximum demand with minimum local generation or now vice versa, maximum local generation output at a time of lowest local demand. Using historical loading data, they can also identify the specific periods in a year that typically result in those grid capacity issues.
So, what happens? The utility comes back to the developer with a report that effectively says, “our system is currently not capable of handling this additional generation and its export”. “If you want to connect you will be required to pay for all the equipment upgrades”. This can stretch to millions of dollars and years of construction time for some projects . Suddenly, the climate goal contributing solar PV project doesn’t seem like such a good investment anymore. And it reduced the chances of achieving the NYS clean energy goals.
This very real scenario has happened many times and developers are frustrated. So, what is the solution?
Solution
Smarter Grid Solutions developed a software solution known as Distributed Energy Resource Management System (or DERMS) to help project developers get connected more efficiently and at a fraction of the cost – we call this software Strata Grid. Our advanced version of DERMS allows utilities to monitor and control local PV and other generation to make it fit within the grid capacity limits on a second-by-second basis. Implementing this method known as curtailment (or literally reducing the energy production from the project) we are able to provide a safe and secure means to limit only the exact excess amount of exported clean energy for those ‘worst case scenario’ hours in the year but provide full grid access for the rest of the year.
We begin by conducting a curtailment analysis and presenting this to the PV developer. Developers often work to a rule of thumb that a project with up to about 5% curtailment would be a good candidate for a curtailment or FICS connection. This can be an attractive option for developers because they will be able to get their projects connected to the grid much sooner. The small % loss in generation production over the year is more than balanced by the millions of dollars saved in grid interconnection and upgrade costs.
Our Strata Grid system monitors for all congestion issues on the grid and resolves these for the utility company. It keeps the clean energy flowing through the lines, cables, transformers and substations, by issuing commands to our local Element Grid controller at the DER sites to curtail output only when a grid capacity problem is detected.
Most utilities help keep things fair by using a ‘last in first out’ (LIFO) arrangement with developers to make it clear to all which generators will respond to a grid constraint and in which priority order. The arrangements that govern the access through the flexible interconnection solution (FICS) are expected to evolve as FICS is used more.
Our Strata Grid software has been operational for many years in the UK with all the major utilities using our DERMS products to manage over 400MW of flexible connected generation. Our work with RG&E / AVANGRID is the first fully implemented, live FICS deployment in the US. Using Strata Grid to increase grid hosting capacity, RG&E were able to approve three 5MW PV (15MW) flexible connection sites onto the AVANGRID system instead of the initial firm connection offer of 2.6MW. The sites went live in May 2021.
With FICS now thoroughly tested and proven for solar PV projects in New York State (and available in both RG&E and NYSEG service territories) we expect application to the many interconnection queues and grid constraints across the US. We also know that other utilities and PV developers want to roll this solution out in their areas and are already exploring a range of different applications of FICS to move the clean energy agenda forward.
