Solar electricity every hour of every day is here and it changes everything

1 kW of stable solar power across 24 hours of the day can be achieved on an average day in a sunny place like Las Vegas with 5 kW of fixed solar panels and a 17 kWh battery.

97%

The sunniest regions in the world can get as close as 97% of the way to 24/365 solar – stable supply every hour of every day of the year.

104 $/MWh

Achieving 97% of the way to 24/365 solar in very sunny regions is now affordable at as low as $104/MWh, cheaper than coal and nuclear and 22% less than a year earlier.

About

This report unpacks the concept of 24-hour electricity supply with solar generation — how solar panels, paired with batteries, can deliver clean, reliable electricity around the clock. It compares cities across the world, showing how close they can get to solar electricity 24 hours across 365 days (24/365 solar generation), and at what price. Focused on project-level applications like industrial users and utility developers, the report shows how batteries are now cheap enough to unlock solar power’s full potential.

Executive summary

24-hour solar generation is here — and it changes everything

Solar electricity is now highly affordable and with recent cost and technical improvements in batteries — 24-hour generation is within reach. Smooth, round-the-clock output every hour of every day will unleash solar’s true potential, enabling deeper penetration beyond the sunny hours and helping overcome grid bottlenecks.

On June 21st — the Northern Hemisphere summer solstice — the “midnight sun” circles the sky continuously, providing 24 hours of daylight and theoretically, 24 hours of solar electricity generation. Thanks to advances in battery storage, this phenomenon is no longer limited to the Arctic.

Rapid advances in battery technology, especially in cost, have made near-continuous solar power, available every hour of every day of the year, an economic and technological reality in sunny regions.

Industries like data centres and factories need uninterrupted power to function. At the same time, the rising push for hourly-matched carbon-free energy goals — pursued largely through corporate Purchase Power Agreements (PPAs) — is increasing the demand for clean electricity every hour of the day. While solar is now extremely affordable and widely available, its real value will only be realised when it can deliver power consistently to meet the demands of a growing economy, even when the sun isn’t shining.

24-hour solar generation enables this by combining solar panels with sufficient storage to deliver a stable, clean power supply, even in areas without grid access or where the grid is congested or unreliable. While this may not solve every challenge at the grid level, since not all places are as sunny and the electricity demand varies hourly and seasonally, it provides a pathway for solar to become the backbone of a clean power system in sunny regions and to play a much bigger role in less sunny regions.

This report explores how close we are to achieving constant, 24-hour solar electricity across 365 days in different cities around the world, and what it would cost to get there.

Key takeaways

24-hour solar generation is possible – just 17 kWh of battery storage is enough to turn 5 kW of solar panels into a steady 1 kW of 24-hour clean power.

On an average day in a sunny city like Las Vegas, US, providing 1 kW of stable, round-the-clock power requires 5 kW of fixed solar panels paired with a 17 kWh battery. This combination can deliver a constant 1 kW of solar electricity every hour over a full 24-hour period – and this amount of battery will be sufficient for most regions across the world.

It is possible to get 97% of the way to constant solar electricity every hour of every day of the year (24/365) in the sunniest cities.

Cloudy days mean that 24/365 solar generation – maintaining the same constant solar output every hour of every day of the year – would need so much solar and battery that it is likely uneconomical. However, in sunny cities it is possible to get more than 90% of the way. Las Vegas can reach 97% of the way to 1 GW constant supply and Muscat in Oman – 99%, using 6 GW solar panels and 17 GWh battery. Even cloudier cities like Birmingham can get 62% of the way to a constant supply every hour of every day across the year.

The economics are great in sunny cities – just $104/MWh to get 97% of the way to 24/365 solar, 22% lower cost than just a year earlier and cheaper than new coal or new nuclear.

In a sunny city like Las Vegas, the estimated Levelised Cost of Electricity (LCOE) at this 97% benchmark is $104/MWh. This is already 22% lower than the $132/MWh estimate based on global average capital costs of solar and battery a year earlier. It is also more cost-effective than coal in many regions ($118/MWh) and far cheaper than nuclear ($182/MWh).

The emergence of 24-hour solar generation marks a fundamental shift in how solar fits into the broader power system. With the ability to deliver electricity around-the-clock, solar can now support 24/7 clean energy contracts (PPAs) for industries which require continuous power, not just daytime supply. This is extremely valuable for emerging economies, where solar-powered industrial and economic zones can emerge in sunny areas far from existing grid infrastructure. At the same time, it can also bring substantial potential savings on grid expansion costs – allowing up to five times as much solar capacity to be installed behind the same grid connection, maximizing existing assets and deferring costly upgrades.

As costs continue to fall and deployment accelerates, solar-plus-storage is emerging as the default model for clean power in the sunniest parts of the world — both on and off the grid. To fully realise its potential, energy policy must now catch up, by integrating 24-hour solar generation into planning frameworks, electricity market design and infrastructure development strategies.

This is a turning point in the clean energy transition. Around-the-clock solar is no longer just a technical possibility and distant dream, but an economic reality. It unlocks game changing opportunities for energy-hungry industries like data-centres and manufacturing. Solar will be unleashed. The change is new – the costs and quality of grid batteries have improved so much in the last 12 months. Now it’s time for policy and investment to catch up.

Kostantsa Rangelova
‍Global Electricity Analyst, Ember

Next Chapter

Chapter 1: How batteries will unlock solar's true potential