Grey

1. Energy systems - manufacturing - sustainability.

Relatively more polluting, and less sustainable.

2. Markets - pricing - visibility.

Lacking in full transparency, visibility and open access.

For example, a grey market.

3. Law - regulation - ethics.

A grey area is something about which there is currently doubt, uncertainty, or ambiguity.

See also

• Brown
• Clean
• Dirty
• Ethics
• Green
• Grey area
• Grey energy
• Grey hydrogen
• Grey market
• Law
• Opaque
• Regulation
• Sustainability
• Transparency