{"schemaVersion":"report-figure-v1","report":{"slug":"solar-beam-diffuse","title":"Beam and Diffuse: Two Kinds of Light, and Where a Tracker Pays","url":"https://solaranalytica.com/solar-beam-diffuse","datePublished":"2026-05-07","lastReviewed":"2026-09-17"},"figure":{"id":"beam-against-total","title":"Annual beam irradiance against annual total irradiance, eleven profiled sites","unit":"kWh per square metre per year","valueLabel":"GHI kWh/m²/yr","valueBLabel":"DNI kWh/m²/yr","provenance":{"dataSource":"NASA POWER long-term-average annual totals, as tabulated in this report","dataType":"Observed climatology","scope":"Eleven of the 44 profiled sites","statistic":"Annual total on the horizontal; annual beam on the sun-facing normal"},"caption":"The same total, two different skies: eleven of the 44 profiled sites, annual total against annual beam. Beam is measured on the sun-facing normal, so it exceeds the total at clear high-beam sites, which sit above the line. Cairo and Riyadh receive within seven per cent of each other in total and differ by a fifth in beam. NASA POWER long-term averages, from the table below.","series":[{"label":"Calama","value":2621,"valueB":3224},{"label":"Upington","value":2291,"valueB":2884},{"label":"Phoenix","value":2126,"valueB":2783},{"label":"Ouarzazate","value":2175,"valueB":2411},{"label":"Cairo","value":2372,"valueB":2274},{"label":"Riyadh","value":2225,"valueB":1807},{"label":"Dubai","value":2028,"valueB":1589},{"label":"Berlin","value":1065,"valueB":983},{"label":"Jakarta","value":1733,"valueB":889},{"label":"London","value":1096,"valueB":1070},{"label":"Reykjavik","value":822,"valueB":815}]},"csv":"https://solaranalytica.com/reports/solar-beam-diffuse/figures/beam-against-total/data.csv","publicationState":"fixed-edition","boundary":"The figure remains bound to the report edition. A newer upstream release creates a review obligation and never rewrites these rows automatically."}