Invented in 2011 by the Shenzen Meideal Music Instruments Company, this is the only electronic guzheng currently produced. The informative Eason Music store in Singapore did a brief impression of it back in 2011. It's been a few years and it's making its way into more stores. This picture is from the 2015 Chinese Music trade show/ expo in Shanghai. Meideal maintains a spec sheet on their website.
This works on similar principles to an electric guitar. Played without amplification it's reportedly very quiet, making it an interesting prospect for those who need to practice more than their family or neighbors can stand. Then plug it in and you get the sound level you'd expect.
Unfortunately I have not played one of these personally so I don't know what range of customization it might have.
If you're looking for just amplification you could of course put a mic system inside an acoustic guzheng, but that would not allow you to quiet the instrument, nor, presumably, modify the output.
I look forward to playing this one day!
Image Source: ChineseZither Facebook Used with permission.