Hi @numundo !

Also trying to figure this out !

Here are a few links that tend to claim that bitcoin energy consumption (which is based on a PoW) might *not * be a problem :

• https://bravenewcoin.com/insights/should-we-think-of-bitcoin-as-a-store-of-energy
• https://www.forbes.com/sites/christopherhelman/2018/01/16/bitcoin-mining-uses-as-much-power-as-ireland-and-why-thats-not-a-problem/#61c8fd8b4589
• https://cointelegraph.com/news/bitcoin-mining-costs-more-electricity-than-houses-but-its-a-non-issue

PoS (already used by wave and soon by ETH) is generally presented as a more environmental-friendly consensus algorithm . However it might lead to a centralized crypto financial system (https://www.coindesk.com/proof-of-stake-could-lead-to-crypto-banking-lets-avoid-that)

I'm convinced by the idea of commons and real P2P economy built upon blockchain technology (see for example the democracy.earth or the holochain projects).

But yes the question remains : how to build a decentralized system that can allow trust between participants without the need of outrageous amounts of energy to run the network ?

Maybe that projects such as burstcoin that use free disk space to secure the blockchain (Proof-of-Space) is a good starting point : https://www.burst-coin.org/