Solar energy is even cheaper than you think

How prevalent is solar power, really? According to researcher Jenny Chase, it's already displacing fossil fuels in key energy markets around the world. She explains the rise of affordable solar power and dives into how her team tracked its rapid installation in unexpected countries, offering a vision of a brighter, more sustainable future.

Solar energy is even cheaper than you think

You've probably all heard that solar modules are cheap, but I'm not sure you appreciate just how cheap. You can buy a solar module for the price of about eight cups of the posh coffee you get here in Brussels. You can make solar panels into a fence, and it's not significantly more expensive than ordinary fencing material.

But this isn't just great news for rich Europeans who drink posh coffee. Solar power is starting to displace fossil fuels in the countries that most need cheap and clean electricity.

Now, I have been an analyst of this sector for nearly 20 years and the growth is really impressive. This chart shows new solar built every year, and last year, 444 gigawatts of solar modules got installed worldwide. More than half of that was in China, actually. Four hundred and forty-four gigawatts is quite a lot. It's more than the power capacity of Japan. And even more is being installed this year. It's probably just under 600 gigawatts.

But I have to take you off on a diversion now to complain about how hard my job is. Back in 2007, there were about 12 countries installing solar, and the official data coming out of them was good. Now my team is trying to cover 146 solar markets, and some of the data is really bad. Even Germany and Spain are installing more solar than is in their official data. So what hope is there for good data about countries in Africa or Southeast Asia?

Take, for example, Pakistan. Now this chart shows the exports of solar modules from China to Pakistan according to China Customs. It reports in dollars, but we convert to gigawatts using average prices. So the official data on how much solar is installed in Pakistan is that there's less than three gigawatts in the country. But more solar modules left China for Pakistan in 2022 alone. Now, we did think that substantial amounts of those were being re-exported to Afghanistan to run irrigation pumps, to grow poppies, to make heroin. And there's also a money laundering scheme which distorts the data. But these don't seem to be that big. And in 2024, things got ridiculous. Sixteen gigawatts of solar modules have left China for Pakistan in the first eight months of this

I worked with a machine-learning and satellite data firm called Atlas Maps to detect the solar modules in Pakistan. Now, the great thing about detecting solar modules using satellite data is you can't really hide solar modules. The bad thing is that they are distributed, they're quite small installations, and sometimes they look a lot like greenhouses or skylights. But Atlas Maps found 443 installations in Pakistan, many of which we had no idea existed, and looking a lot like the ones on the right of this map, that's some rooftop solar.

It also missed some, like, you can see some on the left of this map that the machine-learning algorithm just did not detect. But you can see them. You would see them better 

What the satellite data did confirm is that solar modules in Pakistan are installed near the industrial clusters of Lahore, Karachi and Islamabad. And actually, if you go on Google Earth and just look at a random spot somewhere in Pakistan, in these cities, you can see that loads of the roofs have solar panels on them. It's really incredible.

So the solar boom in Pakistan is really happening. It's not just an artifact of China customs data.

So why? So unfortunately, Pakistan is vulnerable to extreme temperatures. In 2024, 500 people have died in Pakistan in heat waves and temperatures reached 52 degrees Celsius So this is a country where people really need fans and air conditioning to survive. But power is expensive in Pakistan, increasingly expensive, and the total power capacity per person in Pakistan is 1/18 as much as it is in the United States. This is a country that really needs power.

Now, the good thing about solar panels is that they generate in the daytime. So if you want to run air conditioning and fans, they're generating at the right time to do that. And we're pretty sure that this is what businesses and homes in Pakistan are doing. They're installing solar panels to reduce how much they have to pay the grid and to run their cooling systems, as well as the other stuff that they do.

But this is a problem for the largely coal-fired grid in Pakistan because it's losing its best customers, which means it has to put up the prices for its remaining customers to fund the continuing operation of its coal plants. Which means that those remaining customers have higher prices and even more reason to go solar. And the power demand in Pakistan fell nine percent in 2023 as tracked by the grid. And this is probably partly because power is expensive, but also because of all these solar panels that are not being seen by the grid.

So ... As analysts -- obviously, this is complicated, but we feel generally glad that Pakistanis are getting their power from cheap and clean sources. It seems in general a good thing. But you can't always expect solar build to just go steadily up. Solar markets are more like a roller coaster. Actually, we call it the solar coaster.

Take, for example, South Africa. This is data on rooftop solar new build by month from state utility Eskom, which has a really interesting way of tracking this data. It estimates rooftop solar build by the power demand it doesn't see on the grid at particular times. There was a boom in solar installations in South Africa because it was a really bad blackout season, and people literally built solar, so they had power.

And as analysts, we got really excited about this. A gigawatt of rooftop solar was built in two months. A gigawatt is the size of a medium-sized coal-fired power plant. OK, it only runs in the daytime, but it works. So we got really excited. We thought that South Africans would copy their neighbors, and the South African solar market would keep going up and up and up. We were wrong about that.

The solar market has fallen back actually in South Africa in 2024, and this is because there were fewer blackouts. And this is partly because Eskom fixed its coal-fired power plants. Yay! But also because the solar is helping to support the grid.

So it's not always simple, but cheaper solar power is helping poorer countries to meet their power demand without increasing fossil fuel use.

And this is what makes my job interesting. But what we need is to stop burning fossil fuels. And it's most obvious that solar is helping there in markets with less unmet need for power. Take California, for example. This is an average day of power supply on each year from 2012 to 2023. In 2012, California got 43 percent of its power from gas burned in state, and it imported 29 percent. By 2015, you can see the little yellow bit in this chart, that's large-scale solar eating into power imports in the middle of the day. And by 2023, on an average day, there is so much solar that the state is exporting power around noon.

So this is having an impact. What's next? Well, do you see the little pink bit in 2022 and 2023. That's batteries. Batteries are doing exactly what they're meant to do. They're charging on solar in the daytime, and they're discharging in the evening so that the gas-fired power plants don't have to be ramped up. And thanks to all these trends, California carbon emissions per unit of electricity generation have fallen over 30 percent since 2012.

So solar power is pushing out fossil fuels in both richer and poorer countries. And the next step is probably batteries working with solar and working with wind and other renewables to continue to push out fossil fuels. This is actually working. And that is why I have hope that we can beat climate change.

Thank you.