Impact of electricity tariffs on optimal orientation of photovoltaic modules

dc.contributor.authorHaysom, Joan E.
dc.contributor.authorHinzer, Karin
dc.contributor.authorWright, David
dc.description.abstractMaximum revenue (or cost saving) from non-tracking photovoltaic (PV) modules used for distributed generation can be achieved by a module orientation that depends on how the electricity tariff varies with time of day and time of year. Many jurisdictions have real-time market prices of electricity for large customers, time-dependent tariffs or tariffs that depend on peak demand. This paper quantifies the impact of such tariffs on the optimal orientation of non-tracking PV modules using example tariffs from California, Nevada and Ontario, and concludes that modules should be oriented to the west of south by 28°, 46° and 54° respectively. In order to focus on the impact of tariff, the results are based on simulations of a constant-efficiency PV system operating under year-round clear-sky conditions. A generalized relationship between optimal azimuth and the on- to off-peak ratio of time-dependent tariffs is also presented. The paper quantifies the sensitivity of the dollar value of the power generated to non-optimal orientation of the modules. Compared to conventional south facing modules tilted at an angle just under the latitude, the paper demonstrates that optimal orientation adds 4–19% to the revenue/cost savings, potentially affecting the economic viability of a PV installation. The peak demand components of the Ontario tariff have a much more substantial effect on the optimization and resultant revenues (cost savings) than variations in the real-time market price of electricity.
dc.description.sponsorshipThe authors acknowledge the support by the Ontario Research Foundation—Research Excellence Grant, the Natural Sciences and Engineering Research Council of Canada and the Canada Research Chair program.
dc.titleImpact of electricity tariffs on optimal orientation of photovoltaic modules
CollectionScience informatique et génie électrique - Publications // Electrical Engineering and Computer Science - Publications