# Model: rooftop PV potential up 13–20% by 2100, but max share of global electricity falls to 30–47%

- Published: 2026-11-13 05:07 UTC
- Section: Power & Energy › Energy
- Tags: rooftop photovoltaics, RPV potential, urban densification, SSP-RCP scenarios, global electricity demand, per capita solar potential, developing countries solar, clean energy access
- URL: https://realtech.media/news/rt-47f5940eed26e224354c4a93_model_rooftop_pv/

**A projection in The Innovation Geoscience covers 2015–2100 under four scenarios: urban expansion adds roof area, while densification and demand growth cut the share roofs can supply.**

![Model: rooftop PV potential up 13–20% by 2100, but max share of global electricity falls to 30–47%](https://realtech.media/media/2026/11/f650b01a7cf0f48a.jpg)
*Dr. Chinchu C., Wikimedia Commons, CC BY 4.0*

Global rooftop photovoltaic (RPV) potential will grow by 13–20% between 2015 and 2100 under four socioeconomic-climate scenarios, according to a modelling study in The Innovation Geoscience. [1] The authors combined the scenarios (SSP-RCP) with electricity demand projections. Over the same period, the maximum feasible share of RPV in the global electricity mix falls from 117% to 30–47%. [1]

## Baseline and drivers of growth

In 2015, global RPV technical potential was 23.9 petawatt-hours, about 3.3 megawatt-hours per person. [1] The distribution was uneven: 8.3 MWh per capita in high-income countries, 3.1 in upper-middle-income, 1.5 in lower-middle-income and 2.1 in low-income countries. More than 80% of countries had technical potential above national electricity demand.

The growth to 2100 is driven mainly by urban expansion. [1] Climate change acts in both directions: under low-emissions scenarios it adds 2–3% to potential, while under high-emissions scenarios it subtracts 3–4%, offsetting nearly one-fifth of the gains from rooftop expansion. [1] Low- and lower-middle-income countries, which urbanize fastest, gain more than 15% in every scenario, but in high-emissions cases climate losses consume roughly 20% of that gain.

## Densification and demand

Cities are densifying, so roof area per person shrinks even as total roof area grows; per capita potential and population size are strongly negatively correlated. Global electricity demand is projected to reach 2.8–4.6 times current levels by 2100. Together, these trends reduce the share of demand that roofs could cover. [1]

Developing countries, particularly the least developed, are affected most. Many are projected to shift from supply-demand ratios above 200% to deficits larger than those of wealthier countries, despite gaining total potential. [1] In low-income countries, per capita potential declines in every scenario, and after mid-century they have the lowest per-person levels.

The authors propose embedding climate action into urban planning and accelerating global collaboration on technology. They say this is needed to limit disproportionate impacts on countries that rely on rooftop solar for access to clean electricity. [1]

## Sources

1. [The Innovation Geoscience](https://doi.org/10.59717/j.xinn-geo.2026.100222)
2. [EurekAlert](https://www.eurekalert.org/news-releases/1151407)

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Source: RealTech, realtech.media — https://realtech.media/news/rt-47f5940eed26e224354c4a93_model_rooftop_pv/