I don't have one as it impacts my feed-in-tariff for solar PV. Currently the assumption is that I use 50% of the power I generate, and I get paid to export 50%. In reality, currently, it's probably far less as I'm at work when the power is being generated.
With a smart-meter they know how much is being exported and I get paid for that. So until that balance shifts, I'll stick with submitting my readings every now and then.