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February 2, 2026
A year of solar acceleration: the Q4 2025 Solar Asset Mapper release
From China’s runaway growth to new hotspots in the Philippines and South Africa — TZ-SAM’s latest update captures a record year for global solar, plus key lessons from 2025.
Summary
TZ-SAM is a global, asset-level solar dataset built with planetary-scale machine learning, designed to track solar deployment consistently and at speed from satellite imagery.
In the Q4 2025 release, detected global solar capacity rose 5.1% to 1,246 GW (+34.9% year-on-year), with the dataset now covering 106,800+ facilities and adding 2,085 new sites this quarter.
Across 2025, TZ-SAM delivered four full release cycles, identifying installations ahead of public reporting, cutting production time to under 15 days, and issuing its first commercial licences.
The latest quarterly release of our Solar Asset Mapper (TZ-SAM) is now available. This update captures recent global solar trends as the year comes to a close. We’ll be also taking a look back at what we’ve learned from TZ-SAM in 2025.
What is Solar Asset Mapper?
Solar deployment continues to expand across regions and markets, making comprehensive and timely tracking increasingly complex. That’s where TZ-SAM comes in: a global, asset-level solar dataset built using planetary-scale machine learning.
Learn more about TZ-SAM’s origins in our Explainer, and improvements to its underlying detection algorithms in our Q3 2024 Update.
What's in this quarter's release?
In the Q4 2025 dataset, TZ-SAM registered a 5.1% increase in detected solar capacity worldwide, bringing total identified installations to 1,246 GW. On a year-on-year basis, this represents a 34.9% increase in detected global solar capacity.
As of the end of 2025, our global inventory of solar facilities in TZ-SAM has surpassed 106,800. Compared with the previous release, the dataset expanded by an additional 1,660 square kilometres of solar coverage (up 5.6%), driven by the addition of 2,085 individual facilities (up 2.0%).
From a geographical perspective, solar deployment remains concentrated in a small number of countries. Based on TZ-SAM detections, the top five nations now account for 71.7% of total global capacity, marginally higher than 71.4% in the earlier quarter.
Growth trajectories among these solar superpowers continue to diverge, at least through the lens of TZ-SAM, which is especially effective at capturing utility-scale solar assets.
China remains firmly in the lead, recording quarterly capacity growth of at least 7.3% and further widening its gap with the United States. Over the course of 2025, China added 188 GW of solar capacity, which was more than five times the amount added by the United States. As a result, the capacity gap between the two countries expanded from 215 GW to 369 GW within a single year.
India also maintained a strong momentum, expanding by 5.2% in the fourth quarter and 28.4% year-on-year. By contrast, TZ-SAM detections indicate that Japan is showing signs of stagnation, with quarterly growth failing to exceed 1.0%.
In the spotlight: the Philippines and South Africa
In this update, we also highlight two smaller markets that recorded notable performance in 2025, based on TZ-SAM findings.
First, the Philippines. The Southeast Asian country registered a strong increase in solar deployment over the past year, albeit from a relatively low base. As of the end of 2025, TZ-SAM identified 3.7 GW of installed solar capacity in the country, representing a 44.7% year-on-year increase.
This trend is consistent with reported developments on the ground. Over the past twelve months, developers have completed or commissioned several large scale solar projects, including ACEN’s 60 MW San Manuel solar plant in Pangasinan province, and Meralco’s 365 MW Terra Solar megaplant in Nueva Ecija province. Both assets were detected by TZ-SAM’s machine-learning model and incorporated into the latest dataset. (Fun fact: these plants are not yet visible on Google Maps, due to the lag in its satellite imagery updates!)
TZ-SAM estimates also broadly align with official government statistics. According to the Department of Energy’s most recent disclosure, released in July 2025, total installed solar capacity in the Philippines stood at 3.4 GW.
We expect to identify new installations in the coming quarters, as the Department of Energy appears to be actively supporting local developers in addressing permitting bottlenecks and grid connection issues to accelerate project completion.
Next up is South Africa. South Africa’s energy transition continues to attract close international scrutiny as its coal-dependent power system faces a prolonged crisis characterised by rolling blackouts and rising electricity costs.
TZ-SAM’s coverage of South Africa’s solar build-out has improved steadily with each quarterly release, capturing both newly commissioned assets and projects under active construction. Notable discoveries this year include the 240 MW Mooi Plaats solar project, currently taking shape in Northern Cape, and the 273 MW Grootfontein solar plant, which entered commercial operations in Western Cape in December 2025.
By the end of 2025, TZ-SAM estimates South Africa’s total installed solar capacity at 6.4 GW. The dataset spans a wide range of system sizes, from small scale rooftop systems of around 0.3 MW to utility-scale solar farms as large as 399 MW. South Africa also stands out for its deployment of concentrated solar power facilities, which feature distinct architectural designs as seen from satellite imagery.
Given the pipeline of projects announced by the regulator and developers, further capacity additions are to be expected in 2026 releases.
Looking back on 2025
Last year, TZ-SAM completed four full release cycles, marking another year of active development and bringing value to users.
Our headline figures underscore the pace of change: detected global installed solar capacity grew by 34.9% year-on-year, while total solar installation coverage across the earth’s surface expanded by 35.8%.
Throughout 2025, TZ-SAM updates closely tracked the pulse of the solar market. The dataset continued to identify new solar installations months before they appeared in corporate disclosures, national statistics, or public mapping platforms such as Google Maps. In doing so, TZ-SAM revealed and validated emerging solar hotspots, confirmed markets with strong adoption momentum, and highlighted countries beginning to show signs of slowdown.
At the same time, the team explored new approaches to better capture the growth of distributed, small-scale rooftop solar systems. These installations are increasingly driving capacity additions in many markets but remain difficult to detect using conventional TZ-SAM methodologies. Using higher-resolution imagery, sampling, automated labelling, and extrapolation techniques, we produced our first estimates of distributed and rooftop solar installed capacity for Pakistan and several Southeast Asian markets.
From a production perspective, the team made substantial progress in shortening production timelines. What once took more than 60 days to complete is now achieved in under 15 days per quarterly release. This efficiency gain further strengthens our confidence in the dataset and its underlying methodology.
Finally, 2025 marked an important milestone with the issuance of TZ-SAM’s first commercial licenses to business users, enabling direct application of the data in real-world decision-making.
With faster production cycles and growing market uptake, TZ-SAM enters 2026 with a stronger foundation and clearer role within the global solar data ecosystem.
When is the next release?
TZ-SAM data is published retrospectively, with data for the preceding quarter delivered in the current quarter.
TZ-SAM users who download TZ-SAM through this form and tick the box opting-in for quarterly release updates have the data delivered directly to their inbox.
What’s next?
Commercial licensing of the TZ-SAM dataset is available for select partners. If you are interested in discussing how we can license TZ-SAM data to support your business, please contact us using this form, and our team will be in touch.
The TZ-SAM dataset is open-access under the Creative Commons license for non-commercial use. Download it now, and register for quarterly updates.
