Is TVSS (transient voltage surge suppressor) a must for every PV system installation?

Hi everyone, I'm new and this is my first post 
Shall I include a TVSS in every installation -- regardless of PV system size? I did 2 100-kwp cap PV plant with a TVSS on the AC side because it was required by the client. Just recently, I did a 10.80 Kwp system without one. What are the possible repercussions? 'Appreciate your inputs!

Shall I include a TVSS in every installation -- regardless of PV system size? I did 2 100-kwp cap PV plant with a TVSS on the AC side because it was required by the client. Just recently, I did a 10.80 Kwp system without one. What are the possible repercussions? 'Appreciate your inputs!
Comments
Think of lightning VS your gear as a single turn, air core, transformer. Really lousy energy transfer, but when you have mega volts and millions of amps, even a 0.001% efficient transformer can fry stuff only expecting a couple hundred volts
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TVSS (Surge Protection Device)
They both are the same sort of thing. The name may depend on who makes it, who sells it, or what you think you want it to do.
The both come in different voltage usage and clamp ratings
Both have Amperage/Jule ratings
In the electronics industry, TVSS is a small device soldered on a circuit board at IO points, like the USB ports on a computer
Neither will Absolutely prevent damage, some carry a "insurance warranty"
http://ecmweb.com/content/demystifying-tvss
|| Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
|| VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A
solar: http://tinyurl.com/LMR-Solar
gen: http://tinyurl.com/LMR-Lister ,
http://members.sti.net/offgridsolar/
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