Exploring the Benefits of Photovoltaic Non-Optimal Orientations in Buildings

AAs Solar Photovoltaics in buildings reaches maturity, grid integration and economic yield are topics of greater interest. The price reduction of photovoltaics has driven a shift in support policies of PV installations in buildings from the feed-in-tariff model, to net-metering and net-billing schemes. The traditional design of photovoltaic installations has considered the optimal orientation of photovoltaic modules to be that which yields the maximum annual energy production. The influence of the consumption patterns and the hourly-variable electricity prices implies that this traditional optimal design might not be the most profitable. Using a full-year dataset for a residential installation, alternative installations using canopies and modules attached to the façades are simulated. Evaluating these alternative installations against a traditional optimal installation, under the Spanish regulation, it is found that the canopy and façade installations offer comparable economic performance despite having a 23% and 39% lower energy yield respectively. The economic evaluation under the new electricity tariffs in Spain shows a better profit for PV self-consumption, reducing by more than 2 years the time of return on investment. The analysis of different alternatives for an industrial PV during the design stage, has allowed us to identify several benefits for these orientations.