Consider space requirements and access. For PV, look for shadows, evaluate for optimal solar radiation and the angle of incidence during peak generating season. If possible, consider solar tracking system that follows the sun during the day and throughout

Consider space requirements and access. For PV, look for shadows, evaluate for optimal solar radiation and the angle of incidence during peak generating season. If possible, consider solar tracking system that follows the sun during the day and throughout the year. This would allow more electricity generated from the same area, though with more infrastructure cost. (See Resources.) 

The key factors in implementing renewable energy for onsite generation include:envelope optimization and efficiency;studying feasibility; selection of appropriate technology;optimizing the mechanical and onsite systems; integrated design develop

The key factors in implementing renewable energy for onsite generation include:

envelope optimization and efficiency;
studying feasibility; 
selection of appropriate technology;
optimizing the mechanical and onsite systems; 
integrated design development;
space and resource allocation;
budget allocation;
Identifying available incentives.