What you could do is bill per energy in e.g. 15 minute chunks, and separately bill for transformer/line capacity by e.g. the peak usage in any such chunk over the contract period, like they do in Germany for atypical load profile industrial users since decades ago.

Net metering is overall just entirely stupid as a concept; measure inbound and outbound flow separately if you can't just measure the 15 minute chunks; bill grid fees on the energy price on inbound and only pay energy price on outbound. Or even bill grid fees on outbound up to one of many available large substations, and thus handle the issue of demand across large distances making buildout of solar in a convenient but far away place not being disincentivized vs. more-demand-local buildout.