There can’t be a conversation about renewables without looking at what came before — hydrocarbons (coal, oil and gas). And there can’t be any conversation about hydrocarbons without going back to 1859. If you’ve ever looked up the first oil well — the name Edwin Drake pops up. The original use of oil — petroleum that is — was in lamps. It was only in the late 1800s that the first refineries were built, first to turn the raw liquid coming out of the ground into lamp oil and then into kerosene. If you checked that handy latin dictionary, it gives us ‘rock oil’, hence the original name of many English-language companies. On the topic of names — fossil fuels are briefly NOT dinosaur juice. In fact, they’re more likely very very VEEERY old plant juice, preserved underground for long enough that heat and pressure had their way and compressed the hydrogen and carbon-rich plant matter into the right shape to become the brown slurry every oil CEO loves.
Before oil there was king coal. No, not Nate King Cole, but coal, the brown-black rocks. Notice anything about it?
It’s solid — and not very easy to fit together. You see, the obvious fact that oil is a liquid made all the difference in why oil became the go-to fossil fuel. You can pipe liquids and they have less wasted space in storage and shipping. Looking purely at energy — anthracite (one of the higher quality types of coal) gives 35 to 42 megajoules per litre and around 10,000 watt-hours per litre, whereas crude oil is 36 to 38 MJ per litre and just over 10,000 watt-hour per litre of volume. But then again, the most common are lignite and bituminous (in other words, not the highest quality), which have more impurities and less energy produced than anthracite and therefore oil too. Still, this means that even when considering the inefficiency, coal is still a top contender and the raw material is rather similar in energy levels, which makes sense if we look at coal usage worldwide — countries like China and India have relied on coal for their power plants because of its abundance and low cost.
But looking at the stuff that gets released when you burn them — coal releases more and worse stuff. Burning coal releases methane, and that is worse than CO2 and nitrogen dioxide. But ultimately, environmental concerns have only recently taken centre-stage in the public’s imagination.
The bigger driver behind oil becoming the big dog of fossil fuels is, you guessed it, cars.
It’s just too unwieldy to take a break at a coal stop and open up your fire-box to load in a couple kilos of coal, when the liquid nature of oil and its final product, petrol (gasoline for our American friends), lets you fill up a tank. Not to mention the way injection mechanisms for petrol and diesel engines need to aerosolize the petrol to fire into engines.
So… oil’s the popular girl, her milkshake brings all the boys to the yard. Great — what about the third musketeer: natural gas?
Natural gas is a catch-all term from synthetic gas and shale gas to liquefied natural gas (LNG) and methane gas. It would be very complicated to analyse them all but the claim goes it’s the cleanest type of fossil fuel. This stems from a 2010 paper by the US National Energy Technology Laboratory that it emits 50% less CO2 than coal and about 20 to 30 less than oil.
Ok, let’s take that at face-value.That’s supposedly the good thing about natural gas that makes it what governments and the gas-producing companies call ‘the bridge to renewables.’ Fine — let’s unpack that. Is natural gas as clean as they say?
While burning the final product is cleaner (if done in well-equipped Combined Cycle Gas Turbines, for example) the problem rears its head when looking at emissions when producing the stuff. This goes for all fossil fuels but during the get-it-out-of-the-ground phase, a lot of methane (the stuff that’s 30 times worse than CO2) gets released. It’s so bad partly because the quantities released are difficult to track and there’s little to no effort to do that from the companies extracting the gas. And that’s before considering the other environmental damage of something like shale gas. Fracking has a terrible record with groundwater and even causes earthquakes.
Right — there’s way more to be covered with fossil fuels but this is about renewable sources — wind,solar, hydro, whatever, just not fossil fuels. We’re getting to that. Renewables come with their own share of problems. And we can’t just pit the bestest, cleanest singular solar panel on grandma’s roof against the biggest coal power plant in the world. (which is in China and produces 16 times the UK’s annual consumption). Equally, we can’t look just at the worst polluting lithium mine in Chile and compare with the least emitting natural gas extraction facility.
So… what are the contenders to fossil fuels?
Everybody has heard about solar, wind and hydro. Not as many about bio-fuels. Then there’s also geothermal and tidal.
And then there’s the black sheep of the family — the least renewable of the renewables. — nuclear. Fun fact — nuclear power itself is renewable (given the technology you could make nuclear fission or fusion with a lot of stuff) but the material currently used in nuclear power plants is finite: uranium and plutonium, for the most part. But I think there’s way too much to discuss about nuclear so it deserves a special post just dedicated to it.
For now, let’s go over the main renewables in the energy mix. The International Energy Agency reports for 2019 as follows:
19% Hydro and other (geothermal, tidal)
7% Solar PV and wind
As you can tell — globally, coal still dominates. This is partly due to it being dirt-cheap in emerging markets like China and India and even in the future, rising African economies might look at natural gas as the next step because of recent discoveries.
While solar has recently started going up as a proportion and the installed capacity is likely to keep going up, there are coal plants that have just been installed that will continue to be part of the energy mix for decades (the time needed for them to turn a profit is about 30 to 40 years), and part of the problem is many older coal fired power plants are only now turning a profit after being installed in the 60s and 70s, meaning the companies operating them aren’t likely to turn them off.
Wind turbines are also catching new wind in their sails — and I stand by that terrible pun — with expansions everywhere from the famously windy American Midwest and Canadian plains to offshore in the North Sea. China in particular is expanding rapidly in both solar and wind. This is partly due to the cheapness of both since technology has advanced so much and there is demand to scale, allowing savings in production and distribution. But the biggest contributor to those savings have been governments the world over who have been investing into renewables since the 1980s through subsidies and research grants. And now they’re cheap enough that even with subsidies being withdrawn, companies can still be profitable.
This isn’t only true of renewables, the shale gas industry that has grown exponentially in the US, relied for years on government research and funding and only broke through the cost barriers in the early 2010s.
Next, let’s look at hydro. Arguably the oldest renewable, it’s existed for as long as we’ve been making bread. Water mills harnessed this power most consistently and historical evidence from Roman times and Han China too shows they’ve been around for over two thousand years. But we’re here to talk about dams, hydroelectric power, that kind of business. The upside is there’s rivers pretty much everywhere and there’s a lot of power to be harnessed. If you take a look at the Hoover Dam, for instance, you’ll know they can last for far longer than the 20 to 25 years of a wind or solar installation. But they do come with gigantic costs too — you’re reshaping the ground, slapping a couple hundred tons of concrete and trying to hold it together for a hundred years, maybe? The bigger they are, the bigger their effects: the Three Gorges Dam on the Yangtze river, upon construction, slowed down the Earth’s rotation by (a measly but it’s there) 0.06 miliseconds.
Then again, the Earth’s rotation fluctuates fairly often so take it with a pinch of salt.
One of the advantages of renewables is their payback period — the length of time it takes to pay back your initial investment. For residential solar panels it’s currently between 7 and 10 years, while commercial installations will take 12–15 years. This depends a lot on whether you can sell excess power back to the grid. Given the expected lifespan of solar panels is around 20 to 30 years with the right upkeep, they have become considerably more profitable lately. Even pension funds (and they are notoriously risk-averse) are getting in on the action. Wind turbines have shorter lifespans of around 20 to 25, and some are retired even quicker at 17 or 18 — see the Xcel Ponnequin Wind Farm in the States.
How do they compare on clean-up, though? Well, for one, as of time of writing this, the United States does require coal mining companies to put aside funds for clean-up but with the decades or even centuries it takes from opening to closing a coal mine, there have been more than a couple of companies going bust, leaving the problem firmly in taxpayer hands. However, while there is at least this requirement for coal mines exists, there’s nothing like this for wind farms or solar panels. No requirement to set aside funds for clean-up, even if that involves just tearing the pylons out of the ground or getting rid of the panels.
Which leads me to my final point I want to cover in this not-so-short summary is that there are also issues with renewables — in extracting the right metals out of the ground for the solar panels and even more importantly, the disposal of the heavy metals — cadmium, lead and arsenic that critical studies have revealed can be washed out of the solar panels disposed of at the end of their lifecycle. And this in months rather than the hoped years. For example, with solar panels there’s a lot of glass that is mostly unrecyclable due to impurities when producing it. Maybe we’ll sort out the recycling process, but right now it’s just e-waste (according to EU regulations, at least). Especially wind blades, which are made of fiberglass so if you leave them, they take up space (they’re built to withstand hurricanes so not easy to crush into bits) and if you try and burn them they release that fiberglass, which is also a big no-no.
This raises a problem not now but in 20–30 years when most of the current surge in installations means thousands of panels end up in the rubbish heap. Unless… and this is where that rare human ability comes in — we forward plan for it. The danger lies in sleeping on it now and only developing the recycling capability when it starts. Instead, we need to start the research now, especially because companies know right now what went into their panels, rather than looking back through the blueprints in 30 years time. Luckily, some government agencies have started looking into it. So far, the only one I found any record of was California’s DTSC back in 2018.
There is a silver lining to this, though. Although only the start, companies like Veolia are looking at using chemical compounds to grind them to dust. Global Fiberglass Solutions is turning them into panels for flooring and houses. Whichever path we use, it’s only the start of a long journey leading to proper disposal and recycling.
It may not make for the prettiest headline — solar and wind aren’t the silver bullet we all hoped for — but I much prefer an honest hard look in the mirror to naively holding them up on a pedestal. But hopefully this spreads. It’s not that renewables are flawed, but rather that we need to consider the impact they have too. The issue with fossil fuels for the longest time wasn’t using them, it was using them without properly understanding their impact and worse still, without doing anything about it. Let’s not make the same mistake with renewables.
Notice I haven’t covered batteries — yes without them you can’t really use solar at night or wind when it’s not breezy, but they come with their own set of challenges and I’d like to cover them in a separate post as well.
So there you go — a god-knows-how-many-minutes summary of renewables vs. fossil fuels. As promised, there will be a separate post on nuclear and another one on batteries.
I hope you’ve enjoyed this deeper dive and look forward to the next post in this series about the world of energy.
1 — https://ourworldindata.org/renewable-energy
2 — https://www.engineeringtoolbox.com/fossil-fuels-energy-content-d_1298.html
3 — https://www.eia.gov/tools/faqs/faq.php?id=77&t=11
4 — Methane emissions on nat gas extraction : https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/grl.50811
5 — https://opinionator.blogs.nytimes.com/2013/09/24/is-natural-gas-clean/
6 — https://www.yaleclimateconnections.org/2016/08/is-natural-gas-a-bridge-fuel/
7 — Data, energy by source: https://www.iea.org/data-and-statistics/data-tables?country=WORLD
8 — Residential Solar PV payback period : https://www.renewableenergyhub.co.uk/main/solar-panels/return-on-investment-for-pv-return-on-investment-for-solar-panels-roi-for-pv-solar-panels-pay-back/
9 — https://www.irena.org/newsroom/pressreleases/2019/Oct/Asia-Poised-to-Become-Dominant-Market-for-Wind-Energy
10 — Solar panel reycling: https://www.greenmatch.co.uk/blog/2017/10/the-opportunities-of-solar-panel-recycling
11 — Veolia’s solution to wind turbine disposal:
https://www.bloomberg.com/news/features/2020-02-05/wind-turbine-blades-can-t-be-recycled-so-they-re-piling-up-in-landfills (potential paywall)