Each option expands here. No jumping to another copy of the same text.
1Landlord approves a permanent rooftop system+
You have written permission and control over a compliant rooftop installation.
Define ownership, maintenance, bill benefit, roof repairs and what happens when the tenancy ends before paying for equipment.
Do not install first and negotiate removal or ownership later.
2Only a portable or non-permanent setup is acceptable+
The lease or building allows only equipment that does not permanently alter the property.
Use products designed for that installation method and check electrical safety, mounting, output and whether you can realistically reuse the system elsewhere.
Do not improvise grid back-feeding or unsafe balcony mounting.
3You do not have clear permission+
The roof, façade, meter or common area is outside your control.
Pause installation and discuss landlord-funded solar, efficiency upgrades or another legal option instead.
Do not treat payment of the electricity bill as ownership of the roof or meter connection.
Decision rule: expected savings should be recoverable within the period you reasonably expect to stay, unless the system is genuinely portable and safe to reuse elsewhere.