Why carbon benefits are increasingly contested
On-site solar PV is one of the clearest contributors to a commercial building's carbon position. But as ESG, NZCBS and investor reporting all mature in parallel, the question is no longer 'how much did the system generate' but 'who is entitled to claim the resulting carbon benefit, and what evidence supports the claim'.
For multi-let buildings in particular, that question now sits squarely with the landlord — and the answer needs to be defensible at audit.
What good evidence looks like
- Half-hourly metered generation, not annual estimates
- A clear split between self-consumption and grid export
- Allocation rules that match the lease, PPA or service charge model
- Carbon factors applied transparently (location-based and market-based)
- An audit trail traceable from claim back to the meter
Where landlords typically get stuck
The most common failure is treating the inverter portal as the source of truth. Manufacturer portals show generation; they don't allocate kWh between landlord, tenant and common parts, and they don't apply DEFRA factors consistently across an estate.
The NZC Microgeneration Intelligence Platform records generation, export and self-consumption at the meter, applies allocation rules, and produces carbon outputs that align to SECR, GHG Protocol and NZCBS — see Carbon Allocation and Reporting for how this works in practice.
NZC Solar — powered by the NZC Microgeneration Intelligence Platform — covers feasibility, monitoring, billing, allocation, reporting and portfolio optimisation for commercial PV. Get in touch via the contact page to discuss how this applies to your portfolio.