Hello,
I’m reaching out for your expertise to assist me with a university project. I’ve chosen to design a system that reduces evening peak demand by charging a battery during the day, utilizing solar power during the day or wholesale prices (especially during negative price events), and discharging it at night. During my research, I stumbled upon Reverse DC-coupled systems and could use some help understanding them better.
I’ve found three resources that discuss this topic:
* [LinkedIn Post by DNV Energy Systems](https://www.linkedin.com/posts/dnv-energysystems_dnv-solar-storage-activity-7120951815864483840-Rycm/)
* [ACELEREX Blog: Solar Storage in ERCOT – AC vs DC Coupling Connection Comparison](https://acelerex.com/blog/solar-storage-in-ercot-ac-vs-dc-coupling-connection-comparison/)
* [Dynapower: Reverse DC-Coupled PV Plus Storage](https://dynapower.com/reverse-dc-coupled-pv-plus-storage/)
Are Reverse DC-coupled systems essentially the same as DC-coupled systems but with a priority to charge the battery first? In other words, intended application is not firm up renewables.
Additionally, I need to consider grid connection codes. I watched a YouTube video by SMA Solar Technology [https://www.youtube.com/watch?v=Uts-CihKteE&ab\_channel=SMASolarTechnology](https://www.youtube.com/watch?v=Uts-CihKteE&ab_channel=SMASolarTechnology), which led me to believe that AC-coupled systems have primarily been used for fast response services, while DC-coupled systems have been used for energy services.
With that in mind, if Reverse DC-coupled systems charge batteries first using solar power and are set to switch from discharging to charging mode when reaching a certain state of charge, can they support both grid forming and grid support services?
Have I understood this correctly? I appreciate any insights you can provide. Thanks!
Source: rhyme_pj