指电讯稿件播发的新闻单位、地点、时间的说明，也有只说明新闻单位和时间。用电发往外地称“电”，稿件发给当地的称“讯”。 http://baike.baidu.com/view/455601.htm

最早的新闻记者往自己的单位发新闻是通过电报的，所以会在前面加上XX电，虽然现在不用电报了，但这一习惯还是沿用下来了，用来代指记者从现场发回的第一时间报道。电在这里指得是原创的，经中新网记者独自采访并撰写的新闻内容。 希望我的回答对你能有帮助。

I think this word came from "telegraph". As you know , telegraph(电报) is the fastest way to deliver the message compared with the normal mail in the past. it was the only way for news reporters to send their messages and the latest news. nowadays the telegraph and Morse code has become relatively obsolete and antiquated, but "电" is well preserved in the newspaper industry, which implies the news is latest, real-time, breaking news.