Light Output Tax (LOT)
Core Purpose
LOT internalises the public costs of artificial light pollution, including disruption to human sleep cycles, wildlife behaviour (especially birds, insects, and nocturnal mammals), astronomical observation, and energy waste.
It is a targeted Pigouvian levy within the broader PETS framework, designed to encourage responsible lighting design without banning useful illumination.
Measurement Methodology
Light pollution is measured primarily through:
- Satellite imagery (e.g. VIIRS/DNB night-time radiance data) averaged annually.
- Ground-based sensors in urban and protected areas for calibration.
- Sky brightness meters at key observatories and nature reserves.
Tax is levied on property owners or operators based on measurable upward light flux and excessive horizontal spill from their premises. Exemptions or reduced rates apply for properly shielded, full-cutoff lighting that minimises sky glow.
Liability and Application
Primary liability falls on:
- Commercial and industrial properties with large external lighting
- Public infrastructure (street lighting, sports facilities, advertising)
- Large residential developments with poor lighting design
Private households with reasonable domestic lighting are generally below the de minimis threshold or taxed very lightly.
Incentive Structure
LOT strongly encourages:
- Use of full-cutoff fixtures and warm-spectrum lighting
- Motion sensors and timers
- Strategic reduction of unnecessary night-time illumination
- Innovation in smart lighting systems
Properties that invest in responsible lighting pay significantly less than those that allow wasteful sky glow.
Interaction with HOT and Other PETS Taxes
Revenue from LOT reduces the burden on Heat Output Tax. This creates a coherent system where reducing energy waste (HOT) and light waste (LOT) both lower an individual’s or business’s overall tax liability.
Advantages
- Addresses a real and growing externality ignored by most regulatory approaches
- Technologically neutral — rewards better design rather than specific technologies
- Low administrative burden using existing satellite data
- Protects dark skies, biodiversity, and public health without heavy-handed bans
Dispute Resolution
Property owners may challenge their assessment with independent lighting audits. Clear technical standards (e.g. IESNA full-cutoff criteria) are published. Appeals are handled at district level with final recourse to county environmental tribunals.