What happens if the floodlights fail or a match is abandoned?

It depends on why the match was abandoned (NSL Handbook Rule 14):

Floodlight failure, or safety and security reasons:

• the remaining minutes are played, not the whole match
• the clubs agree a date, time and venue within 48 hours of the abandoned match, subject to League approval; if they can't agree, the League decides
• the resumed match is a continuation: the two parts count as one match, finished only at the final whistle
• a home club that failed to provide adequate lighting or security pays all affected parties' costs and is charged with misconduct

Weather, the state of the pitch or any other reason:

• the League sets a new date and the match is replayed
• all records of the abandoned match are wiped, except red cards, which stand
• the League covers reasonable costs for a weather replay; for other reasons the Disciplinary Committee can order a club to pay

Night matches need an average of at least 600 lux, with no point below 500 lux, from 90 minutes before kick-off.