What does it really take to build a Solar PV project in a cost effective manner? ©
Part - 2
The starting point of any successful project is to find out if it is even feasible. Why waste the time making site visits and design analysis if the customer isn’t favorably located? The four key elements that need to be identified are:
- Site Evaluation
- Utility Rate Schedule Analysis
- Performance estimate (energy predictions)
- Financial ROI
Be it a small 1 KWp or a 1MWp project, evaluating the site to determine if the Solar modules are going to face the sun is step one. If the modules are not going to be pitched at an angle of a minimum of 5 degrees and an orientation anywhere between 135 Deg (South-East) to 270 Deg (West) and very little shading, there isn’t much reason to be installing a solar PV system.
To maximize energy (KWh) production on an annual basis the optimal tilt angle is Latitude angle and an orientation of 180 deg (due South). This would be true in most installations that involve a Performance Based Incentive (PBI).
On the other hand, if maximizing energy production during Peak Summer hours (as defined by your local utility) is important, in general, a tilt angle of 20 deg and modules oriented at 225 deg (South-West) provides the most energy production during Peak Hours (May – October, Noon to 6 PM in PG&E territory)
That brings us to the next item to consider - Utility Rate Schedule Analysis. Without proper analysis of an end customer’s utility rates a system size needed to zero out a customer’s utility bills would at best be a guesstimate.
Performance estimates need to be made based on a number of factors, like, location, weather, shading, tilt angle, orientation, soiling, module, inverter, etc…. There are a number of free online programs that can be used to get an approximate estimate. The good solar integrators will stand behind their production estimates.
A system that is well designed for the suitable location for which a customer’s consumption patterns and accurate production estimates are made will provide the best ROI. Under the current Federal ITC, the pay back period for a residential or commercial system can be as low as 5 years. After 5 years the energy produces is practically free providing the PV System owner with protection against energy cost (utility bill) escalation.
In each of the above steps there are areas where cost effectiveness can be achieved. Google Earth is one of the quickest ways to do site evaluation. It is by no means the panacea, but a preliminary look-see if one should even bother making a site visit.
There are a number of vendors providing software that can do Utility rate analysis, performance estimates and financial ROI. The key is finding one that best suits your needs. I plan on devoting an entire section to this area in the near future.
In the next segment we will review:
- System Design
- System Optimization
- Design and Equipment Review
- Design Review for code compliance
To be continued...
