# Exploring the Benefits of Photovoltaic Non-Optimal Orientations in Buildings
## 5 Conclusions  
The results presented in this work show that the most common option for the orientation of PV modules (optimal for annual module production) is not always the most favorable for self-consumption installations. For this purpose, two specific cases have been studied of PVSCS in residential and industrial buildings. In the case of PVSCS in residential buildings, the PVSCS located in a building in the Madrid metropolitan area was studied and, using these initial annual data, the results obtained under other PV layouts were simulated; these new layouts used canopies and on facades. With these values, calculations were made to obtain the energy and economic balance of each configuration, concluding that PVSCS installed in orientations other than the traditional optimum for energy production are a viable option. This is largely since the new residential tariffs represent an increase of up to 12% in profit over the previous tariffs. This advantage is coupled with the advantage offered by using other architectural surfaces than the roof, which are not in optimal orientations; this means that a higher power PVSCS can be built and that a higher annual electricity production will be realized. The method used for obtaining a proper comparison between installations of different specific yields was to rescale the PV production to fixed values in a range of annual consumptions representative of Spanish residential sector. The analysis proves that the economic performance of these orientations is acceptable under the self-consumption net billing scheme in force in Spain. * The specific yield ranges from 1097 kWh/kWp for the modules on facades to 1375 kWh/kWp for the canopies and 1560 kWh/kWp for the original configuration, which compares with 1725 kWh/kWp of the energy optimal. * The self-sufficiency index improves up to a 2% over the optimal energy. * The internal rate of return is highest for a PV power of 8 kWp for all layouts and ranges from 10% to 17%. * The time of return of investment is lowest for a PV power of 8 kWp and ranges from 6.5 to 9 years. An additional advantage for these orientations is found in the new residential tariffs, resulting in an increase up to 12% in profit over previous tariffs. The new period of highest prices which \"peak\" before noon can be used in orientations with maximum production in this period. There is also a fair economic performance for these orientations, despite the higher cost assumed in this study for the modules placed on canopies and on the facades. The environmental indicators are good for the alternative installations in non-optimal orientations:  
* The maximum greenhouse gas payback time is 6.4 years for the installation of modules coplanar with the facades. * The average energy payback time rises to 2.0-2.1 years for modules placed on facades from 1.6-1.8 years for modules on the roof. The data from the industrial PVSCS case study suggest that non-optimal PV orientations can present an advantage over traditional south-facing orientations with inclination optimal for yearly energy production. The main advantages found can be summarized as follows:  
* Higher installed power due to more efficient use of available space in roofs, resulting in higher energy production in the available space. The benefit identified in the case study was a 72% higher peak power and a 59% increase in energy production. * Improved economic yield by adaptation to variable electricity tariffs and load patterns of industry using different orientations. * Reduced curtailment of PV production or energy fed into the distribution grid due to the flattened production profile. * Higher potential for reducing peaks of consumption due to the extended period of PV production. The reduction in the number of powers surpasses 69% and the maximum power exceeded is reduced to 45% in this case study. * A more orderly PV layout; easier installation, operation, and maintenance; and improved overall safety for workers.