It would seam; Summer: LED ; Winter: HID
However, you could always purchase a grow room heater (Ebay does em cheap) and just stick to LED.
LED for the win.
- LED grow lights last six times as long!
- Eco-friendly LED grow lighting uses no toxic metals.
- Energy savings range from 50%-70% over HID lights.
- No cooling necessary; no plant burn and decreased risk of fires.
- LED directional lighting requires no reflectors.
- Maximum chlorophyll absorption and flower production.
- Less frequent watering.
- Discretion assured — no thermal footprint.
Bigger yields, longer life, heat efficiency, easy to use, adjustable spectrum of colours, energy saving...