# Exploring the Benefits of Photovoltaic Non-Optimal Orientations in Buildings
## 4 Discussion  
The use of PV orientations non-optimal for energy generation was presented in residential and industrial cases of study. For the residential case, it is found that the economic yield for the discussed orientations is better than its energy yield. One reason is that, by using several orientations, the energy production spreads more uniformly during the daytime, increasing the self-consumption share of PV-produced electricity. The other reason is found in the variable prices for the retail electricity and the surplus electricity fed into the distribution grid. With the maturity of the PV sector, the actual net-billing schemes, such as the current one in Spain, are more appropriate than net-metering policies since the surplus price is indexed to the wholesale electricity market, thus signaling the periods when distributed generation is more valuable [56]. The use of these non-optimal orientations can reduce the electricity interchanged with the grid, especially the energy fed, resulting in a reduction in the energy stress on the grid [57]. Another benefit can be a more  
Figure 12: Screenshot of the monitoring portal showing the electricity consumption and production on one spring day (18 May 2021). The figure shows the 15-min average power in Watts for the consumption and PV production. Figure 13: Heatmaps of hourly values for the industrial PVSCs (**a**) Electricity consumption (**b**) PV production (**c**) Energy imported from the grid. stable production for configurations using facades, which can provide a better match with the consumption profile during the year. The introduction of residential tariffs with higher prices in periods of high electricity consumption will add an additional profit to the Southeast orientations, which produce most electricity in the hours before noon, just within one of the two peak tariff periods. From the data shown in Figure 8, the increase in profits over the current one period tariff ranges between 8% and 16% for PV installations of annual productions from 5 MWh to 15 MWh. For the industrial case, in addition to the considerations discussed for the residential scenario, there are additional factors to take into account. The use of alternative orientations can facilitate larger PVSCs, reduced curtailment of PV production or energy fed into the distribution grid, and simplified installation and maintenance. Furthermore, it is possible to optimize the periods of energy generation to suit the load patterns of the site. The use of PV reduces the maximum power demanded from the grid, in particular, the analysis of the period of available data shows an important reduction in power surpasses. In Spanish industrial tariffs, a surpass is defined as the power demanded in a quarter-hour period exceeds the contracted power. For this industry, the contracted power is 180 kW and, in the first year of operation, there are 1924 quarters with consumption over 180 kW, with a maximum demanded power of 325.89 kW. For the energy taken from the grid, there are 761 quarters with demanded power over 180 kW and with a maximum power demanded from the grid of 293.06 kW. These figures mean that the use of PV roughly decreases the surpasses by 60% and the maximum power exceeded decreases a 23%, reducing maximum demand penalties and providing additional economic savings. The results are in line with the findings in [58], specifically for the small influence of the azimuth angle and the noticeable gains in annual energy production which reduce the tilt angle. To realize the potential of alternative orientations, it is important to stress the necessity of implementing complementary demand side strategies. For example, in Figure 4, it is clear that the use of air conditioning during the night in summer can be shifted to the hours when PV production is high using self-produced PV electricity, therefore providing greater economic benefit. From a wider perspective, the use of these orientations can provide an important increase in the suitable area for PV, beyond roofs [59; 60].