I've periodically seen lightcell and danielle fong in various news / reddit /forums over the last few years and it always seems to be steeped in controversy.

I know next to nothing about the field / tech, but a portion of folks seem to be like "incredible visionary etc. etc." and the another portion like "fringe science / complete bullshit / this is as realistic as cold fusion" kind of thing.

Very interested to hear from folks more in the know of like, high level long term viability / what the implications are etc.

It's a very good idea that is worth pursuing, they are pursuing it. There are many many many problems that need solving between here and "this is a better way to make energy from heat at scale than turning water into steam and spinning a turbine". The science is fundamentally sound but we're nowhere near economic viability.

It's not like cold fusion, the lightcell is based on well-understood physics. The author may be too optimistic with efficiency claim, but those are relatively easy to verify independently.

It probably doesn't help that the website looks like an American Science & Surplus catalog

She seems like someone with an eye for a clever solution to an existing problem, an eye for funding (her compressed air "LightSail" thing raised over $70 million), and maybe a somewhat shaky relationship with practicality.