Modelling the yield of 8.64 kW PV panels installed on a rooftop of a building in the Kingdom of Bahrain

Abstract

PurposeThis paper allows more accurate estimation of the economy in investing in PV electrification for buildings, especially for Gulf Cooperation Council Countries (GCCC) where they have nearly similar climate and building structure. The actual solar electricity yield from this building is used to make empirical modelling.Design/methodology/approachThe accurate automated daily-recorded solar electricity from 8.64 kW solar PV on a rooftop of Sadeem Building at Awali, Bahrain, was modelled to polynomial equations of order of 6. The effect of the tilt (β) and azimuth (Ψ) angle of PV panels for smart and sustainable buildings is studied.FindingsThe correlation of each set of polynomial equation (R2) is listed and had reached a highest value of 0.9792 (for order of 6) with lowest value of 0.1853 (for order of 1). The model may be also applied to the GCCC. The results show that each kW of PV will have a solar electricity yield, on average, of 4.1 kWh. It also shows that the tilt angle has little influence on the solar electricity yield (less than 10%) when the tilt angle changed from 26° to 0° or from 26° to 50°. The influence of the azimuth angle is found to be more than 50% in changing Ψ from 90° to 180°.Research limitations/implicationsThe model may not be restricted to Bahrain but applies – to a certain extent – to GCCC (six countries) and to other countries having buildings with similar roof design and at latitude close to the latitude of Bahrain.Practical implicationsThe model enables developers and investors to estimate, with high accuracy, the solar electricity provided from a building if PV panels are to be installed on its rooftop (or facade) at different tilt (β) and azimuth (Ψ) angle for smart and sustainable buildings.Social implicationsEmpirically finding out how much each kW of solar PV integrated to the building will produce solar energy electricity (in kWh), that is, 1 kW of PV yield, on average, 4.1 kWh.Originality/valueEstablishing empirical models to evaluate the outcome of each installed kW of PV panels. Each 1 kW installation of PV panels is 4.0 kWh/day, on average. This is less than what commercial companies claim for this region, that is, 1 kW produces 5.5 kWh/ day – which affects the estimated economic outcome of PV projects.

A domestic rooftop PV system: a step towards retrofitting the built environment to combat climate change in Bahrain

“…The annual average of the specific yield for this domestic building was 4.13 kWh/kWp/ day. In comparing this value with the first 8.64 kW BIPV at Sadeem building of Bapco in Awali (company building (Alnaser and Alnaser, 2017), Bahrain), this value (4.13 kWh/kW/day) seems to be close to that reported for the Bapco house, which has an SY ranging from 3.6 kWh/kW/day to 4.6 kWh/kW/day, with an average 4.13 KWh/ kW/day.…”

“…Surprisingly, in all summer months of 2018 and 2019 we detected no daily solar yield at more than 45.25 kWh. This clearly attributed to effect of the solar PV tilt angle (12 °) and azimuth (160 °), for if the PV panels' tilt angle was 26 °and their azimuth was 180 °, this would definitely lead to the highest daily solar electricity generation in June and July (Alnaser and Alnaser, 2017).…”

“…The second PV installation was conducted on the Sadeem building in Awali in 2014 by Bapco (Alnaser, 2017;Alnaser and Alnaser, 2017). There are 36 PV panels on the roof of this building, each having 240 Wp, meaning the total installed power is 8.64 kW.…”

The performance of four domestic rooftop 7.8 kW − PV in the Kingdom of Bahrain: toward low building emission

“…The total area of all PV system is 46.6 m 2 , therefore, 50 kWh means a useful incident solar radiation of only 102 W/m 2 if the sunshine duration is 10.5 hrs; this means the efficiency of the PV panels never exceeded 17% otherwise it should lead to solar radiation equal to 600 W/m 2 -which is the highest daily solar radiation in Bahrain. This clearly attributed to effect of the solar PV tilt angle (12°) À as the closer to latitude of the country the more solar incidence throughout the year with peak in spring and autumn À and azimuth (160°) as if the PV panels tilt angle is 26°and their azimuth is 180°would definitely lead to largest daily solar electricity in June-July [7].…”

“…The second PV installation was made on a sponsored building at Awali in 2014 by Bapco, refer to references [6,7]. There are 36 PV panels on the roof of this building, each having 240 W p , so the total installed power is 8.64 kW.…”