NL coverage gap: distributed greenhouse CHP (glastuinbouw WKK, ~3-3.5 GWe) entirely missing

Summary

The combined dataset systematically misses the Dutch greenhouse CHP fleet (glastuinbouw WKK / gasmotoren): roughly 7,000 gas engines, ~3-3.5 GWe, mostly 10-20 kV DSO-connected (Westland, Aalsmeer/Haarlemmermeer, Oostland, Venlo/Noord-Limburg, Agriport A7). This is a large, real block of dispatchable NL gas capacity.

Evidence

In powerplants() (v0.8.1 and current master), the Netherlands has 35 CHP units, all >= 20 MW - exclusively transmission-connected plants (Sloe, Rijnmond, Diemen, Pergen, Elsta, ...). The count of NL gas CHP below 20 MW is 0.

These greenhouse units sit below the transmission level, so none of ppm's NL-relevant sources capture them: ENTSO-E, OPSD, GEM, GPD, GEO, OSM are all transmission/utility-scale.

Why it matters

For any NL-resolved model this capacity gets mis-attributed to utility CCGT (or omitted), which distorts regional dispatch, congestion, and merit-order (heat-credited CHP bids differently from merchant gas).

Authoritative aggregate sources

• LEI Wageningen - Energiemonitor van de Nederlandse glastuinbouw: ~2,300 MWe installed (2024), ~3,200 MWe peak (2010), ~4,000 gasmotor units.
• CBS Energiebalans Regionaal: per-gemeente self-generation (e.g. Westland ~2.5 TWh/yr).

Proposal

ppm cannot enumerate ~7,000 individual DSO units, but it could ship an aggregated NL greenhouse-CHP source: a small set of cluster rows per region/TSO-substation (~16 rows), Set=CHP, Fueltype=Natural Gas, behind a config flag, with LEI/CBS provenance. We already maintain a working 2,800 MW / 16-cluster table built from LEI + CBS and are happy to contribute it.

At minimum, the docs should state that distributed sub-transmission CHP (and the NL greenhouse fleet specifically) is out of scope, so users do not assume NL CHP coverage is complete.

Start in the powerplants() entry point and verify how the Netherlands currently reports CHP units and sub-20 MW coverage. Review the LEI Energiemonitor and CBS Energiebalans Regionaal sources, plus the proposed 2,800 MW/16-cluster table; done means either an attributable aggregated source behind the proposed config flag or documentation clearly stating this coverage gap.