Hello - Craig Fatha 120% buy in here,

HI all,
I have been pleased to see the Ripple discount on my Octopus bill, - and that would be on track for a 6 year ROI on my £4K investment...
I say "would be", because we are retired, live in a listed 1580 built 5 bedroom house plus 1 bed annex that cannot be properly insulated (glazing-wise)
and we have huge gas bills, so,
We are looking to downsize and move to a 50s built 2 bedroomed ex council house just up the road, which would give us a surplus for a proper investment in future proofing the house (extension, insulation, heat pump, solar and batteries, no gas)
I am most interested in knowing if there would be an effective loss of my investment in Ripple, if I were to make the new home completely, or near completely, self sufficient in energy use.

I don't seek to go off grid, but I know that a few people have created homes that make a net profit on energy, selling excess to the grid and buying back less in the mid winter than sold. in the summer.

I just wondered what happens to ripple discount when your electricity bills drop below a certain point...
I am happy to have invested in assisting a transition to fully sustainable energy provision, but also don't want to throw away my savings!