Bitcoin, daily hash rate, future energy consumption and the lightning network

Dear knowledgable bitcoiners,

I love simulation modelling, and I've been playing around with a model to get a better understanding of Bitcoin and its energy consumption. Basically, I used this scientific paper as a starting point: https://arxiv.org/abs/2004.09212. I then added some small components to simulate historical energy consumption of the Bitcoin network, and compared my results to the Bitcoin Energy Consumption Index (https://digiconomist.net/bitcoin-energy-consumption).

Here are the historical simulation results (simulation starting at 9th of july 2016 and running in days):

Bitcoin Energy Consumption from 9th of july 2016 to early june 2021

I then started playing around a little. I ran a simulation going about 20 years ahead while assuming the following:- Daily number of transactions will remain constant at 250 k per day- Transaction fee per transaction remain constant at todays level (measured in BTC)- The energy efficiency of mining hardware also stays constant at todays level- The electricity prices stay constant at todays level- The price of bitcoin increases 5% per year.

This is what I got:

Bitcoin Energy Consumption from 9th of july 2016 to somewhere about june 2041

I then realized that the miners are mostly incentivized by the built-in subsidy right now. In fact, my model estimates that bitcoin miners would only consume about 15 TWH per year if it wasnt for the built-in subsidiy. Due to the halving events, the incentives for mining will go down over time following the next halving as long as the bitcoin price does not increase by more than 45% per 4-ish year period. At least according to my model...

Having realized that, I came to think about the lightning network. Someone told me that the lightning network will basically bundle a lot of transactions such that it becomes only one transaction on the network. This had me wondering, what will happen to the future hash rate if LN bundle a lot of transactions in one transaction, and the block rewards go down significantly? Won't it become much less profitable with mining? Will the network still be secure in a setting where the hash rate is very low?

All the best,
A curious mind

EDIT: Sorry about the bad image quality... I dunno how that happened...