Why build the energy-trading blockchain as a permissioned (rather than permissionless) chain?

Grid endpoints are real, identifiable households and assets, so gating membership by identity gives better security and scalability than an open, anonymous chain — while still decentralising control away from the distributor.

A permissioned blockchain restricts who may join; a permissionless one (like Bitcoin) is open to anyone. For a local grid the participants are known physical endpoints, so:

• Identity restriction improves security — each endpoint registers, e.g. by obtaining a digital certificate through a PKI (public-key infrastructure), before it can trade.
• Scalability and performance — a known, bounded validator set supports far higher throughput than open anonymous consensus, which matters because energy demand is time-critical and cannot wait on slow settlement.

It is still meaningfully decentralized: the ledger is jointly maintained by all endpoints' servers rather than by the LPD, so admission is gated but no single writer controls the state.

Go deeper:

• Public key infrastructure (Wikipedia) — How digital certificates bind an identity to a key so an endpoint can be admitted.