Roof photovoltaic panels depend on 79% less expensive than they were in 2010. These plummeting costs have made roof solar photovoltaics a lot more attractive to families and companies who want to lower their reliance on electricity grids while minimizing their carbon footprints.

But are there enough rooftop surfaces for this innovation to generate affordable, low-carbon energy for everybody who requires it? It’s not just individuals who own their own homes and want to cut their costs who are in requirement of options like this. Around 800 million individuals worldwide go without appropriate access to electricity.

Our new paper in Nature Communications presents a worldwide evaluation of how many roof photovoltaic panels we’d need to produce adequate renewable resources for the entire world– and where we’d need to put them. Our study is the first to provide such an in-depth map of international roof solar capacity, examining rooftop area and sunlight cover at scales all the way from cities to continents.

We discovered that we would just need 50% of the world’s rooftops to be covered with photovoltaic panels in order to provide enough electrical energy to satisfy the world’s yearly requirements.

Method

We designed a programme that incorporated information from over 300 million structures and analysed 130 million km ² of land– practically the whole land surface location of the planet. This approximated just how much energy could be produced from the 0.2 million km ² of roofs present on that land, an area roughly the exact same size as the UK.

We then calculated electrical power generation capacities from these roofs by looking at their area. Typically, roofs situated in higher latitudes such as in northern Europe or Canada can differ by as much as 40% in their generation perspective across the year, due to huge distinctions in sunlight in between the winter and summer seasons. Rooftops near the equator, nevertheless, usually just differ in generation prospective by around 1% throughout the seasons, as sunlight is much more consistent.

This is very important because these big variations in month-to-month potential can have a considerable influence on the reliability of solar-powered electricity because of region. That suggests places where sunshine is more irregular need energy storage options– increasing electricity costs.

Hotspots

Our results highlighted 3 potential hotspots for rooftop solar power generation: Asia, Europe and North America.

Of these, Asia looks like the least expensive location to install panels, wherein nations like India and China– one-kilowatt hour (kWh) of electrical power, or approximately 48 hours of utilizing your laptop computer, can be produced for simply 0.05 p. This is thanks to inexpensive panel manufacturing expenses, in addition to sunnier environments.

The costliest nations for carrying out rooftop solar are the USA, Japan and the UK. Europe holds the happy medium, with average costs throughout the continent of around 0.096 p per kWh.

Roof solar panels appear like they’d be similarly useful in areas with the low population as they would be in metropolitan centres. For those living in remote areas, panels help top up or even change supply from possibly undependable regional grids. And for those in cities, panels can significantly minimize air pollution caused by burning nonrenewable fuel sources for energy.

It’s important to mention that the global electrical energy supply can not rely on a single source of generation to meet the requirements of billions of individuals. And, thanks to adjustable weather conditions and our world’s day and night cycle, and inequality in between solar power demand and supply is unavoidable.

The equipment needed to store solar power for when it’s needed is still exceptionally pricey. Additionally, solar panels won’t be able to deliver enough power for some industries. Heavy manufacturing and metal processing, for example, require large currents and specialised electricity delivery, which solar power won’t yet have the ability to provide.

Despite this, rooftop solar has substantial potential to relieve energy poverty and put clean, pollution-free power back in the hands of customers worldwide. Rooftop panels might be one of the best tools yet to decarbonise our electrical power supply if the expenses of solar power continue to decrease.

Are there enough rooftop surface areas for this innovation to create inexpensive, low-carbon energy for everyone who requires it? We then determined electricity generation capacities from these rooftops by looking at their area. Normally, rooftops located in higher latitudes such as in northern Europe or Canada can differ by as much as 40% in their generation perspective across the year, due to big distinctions in the sunshine between winter and summertime. Roofs near the equator, however, typically just vary in generation possible by around 1% throughout the seasons, as sunshine is much more constant.

Roof solar panels look like they’d be equally beneficial in areas with the low population as they would be in urban centres.