Renewables: are they reliable?
As a world in transition, we’re facing a two-pronged task when it comes to electricity: we need to rapidly decarbonise our grid while massively growing it. ⚡️🔋💡🔌
Growth in electricity demand will come from ‘electrifying’ many of our carbon emitting activities – like driving cars, heating our homes, and making steel – thus reducing their emissions via a clean electricity grid.
Renewables are going to play a central role in this transformation, and need to be deployed at rapid speed and scale. But public discourse on the topic too often clusters at the extremes – renewables are either touted as the obvious, straightforward solution to the whole climate problem, or decried as an unreliable power source that will leave us all grappling with blackouts while we’re trying to cook dinner.
Thankfully, the reality is much closer to the former than the latter. Integrating large amounts of renewable energy will challenge the way we’ve always managed the electricity system, but the good news is, we have the tools to do it. Renewables might be intermittent – but they’re not unreliable.
State of play🏞
In 2020, about 28% of global electricity generation came from renewables, mostly solar☀️, wind🌬, and hydro💧. Renewables are now the least expensive option for new energy in most of the world, and are even cheaper than continuing to run existing energy generators in some countries.
Source: My chart, data from Lazard’s Levelized Cost of Energy Comparison v15.0.
What’s the rub? 🤷♀️
We can’t usually control when renewables generate power, and fossil fuel proponents tend to lean on this point when arguing we need coal and gas in the grid (“for when the wind’s not blowing and the sun’s not shining”).
That conclusion is mostly wrong for three reasons.
Reason 1: Transmission – the unsung hero of the energy transition ⚡️
When electricity is generated – from burning coal, a spinning wind turbine, or sun on solar panels – it travels down long-distance transmission lines (sometimes called ‘interconnectors’) to where the demand is.
This means electricity being generated in one place can be used in another, which is crucial for reliability, because if the sun isn’t shining in Melbourne, power from Tasmania can travel north to keep the lights on; similarly, if the wind isn’t blowing in Minnesota, North Dakota can come to the rescue.
Fun fact: Transmission can also transfer power between countries, not just regions within countries. For example, Australian company Sun Cable is planning to supply up to 15 percent of Singapore’s energy needs by sending solar power under the sea to Asia. 🦘🇸🇬
Reason 2: Clean firming 🔋
‘Firming’ is power that can be turned on and off to meet demand if the sun or wind isn’t producing enough, and it comes in a few different ‘clean’ forms, including:
Hydropower – operators can release, on demand, large quantities of water, which spill down and spin a turbine (but this still depends on seasonal rainfall).
Batteries – which can dispatch energy almost instantaneously over vast distances. I’ll cover batteries in detail in a future Dispatch, but lithium ion battery costs have fallen dramatically (almost 90% since 2010) and are now being used at grid scale.
Reason 3: Demand management 🏠
What if we could actually adapt our patterns of electricity use to better suit renewable output? I don’t mean going without power during dinner time because there’s no solar – rather, I’m talking about things like smart appliances that choose optimal times to run or charge.
Take your future EV. Why not set it up to charge at work while renewable energy is abundant, and then discharge some power from its battery into your home in the evening, taking pressure off the grid at peak demand time?
Fun fact: Ford’s bringing out an electric ute/pick-up that can charge an average family home for three days! 🛻
Ok. So transmission, firming, and demand management help us manage short term fluctuations in renewable output. But have you ever heard of a Dunkelflaute? 🌒
It’s a german word that literally translates to ‘dark lull’ – an extended period (i.e. days or weeks) of limited solar and wind output.
They’re rare, and tend to only become a concern at very high levels of renewable penetration (how much will depend on the country/grid, but this Grattan Institute report suggests above 90 percent in Australia).
Nevertheless, they’re generally considered the biggest reliability challenge to a renewable grid.
Commercial grid-scale batteries aren’t much good in a Dunkelflaute – they’re excellent over a time period of about four hours, but not much longer than that (yet). Hydro can work, but ideally, it requires mountainous, rivery terrain, so it’s not an option for all countries.
To deal with Dunkels, we can:
Use a very small amount of gas-powered generation. But gas is a fossil fuel, meaning we can’t rely on it for firming in the long-term unless we capture the emissions, which remains both expensive and technically challenging. 🏭
Support technological breakthroughs and commercialisation for longer duration batteries, or other kinds of storage like hydrogen. In many cases, the technology is already there and working – it’s just not economic, and we don’t have the incentives or business models in place (e.g. sufficiently high carbon prices) to make deploying it worthwhile. 💸🔬👩🔬
Build very effective transmission systems. The better and more interconnected the transmission system, the more likely it’ll be able to combat a Dunkelflaute. Some studies are very bullish on this idea:
In 2021, Stanford University showed how the US could run a 100 percent renewable energy grid even in extreme weather – with no blackouts, lower energy bills, infrastructure costs with a payback period of less than five years, and no need for batteries with duration longer than four hours. 💡🔌
But others, like the aforementioned Grattan report, show that moving from 90 to 100 percent renewables in a Dunkel-proof way using currently economic technologies would be expensive.
In summary: with good system design, we can get to a very high level of renewable penetration and run a reliable electricity grid. The last little stretch to 100 percent renewables might pose a challenge, but likely not an insurmountable one.
If you’re leaving this page with more questions than answers, don’t fear – in Dispatches to come, we’ll cover the rise of renewables in more detail, including topics like:
Renewables pt 2: what policies best support rapid deployment?
The griddy details: why the way we distribute power has to change.
Batteries: are we there yet?
Topical island 🏝
The IPCC Report 📖
You may have noticed that every now and again a body called the Intergovernmental Panel on Climate Change (IPCC) releases a long and scary report. These are actually very important, especially the one that was just released on 4 April, which assesses global progress on mitigating climate change.
What is the IPCC? 🇺🇳
It’s a UN body that provides policymakers with the latest science on climate change and it’s, well, legit.
It doesn’t do the science – rather, it assesses the thousands of scientific papers released each year in relation to climate change and provides a comprehensive summary of what we know. It’s made up of thousands of experts from around the world.
What’s in the latest report?
“A litany of broken climate promises, ” according to UN Secretary General Antonio Guterres. “It is a file of shame, cataloguing the empty pledges that put us firmly on track toward an unliveable world.” 💔
Or in Jeff Goodell’s words in Rolling Stone, “It not only attempts to synthesize the complex interplay of chemistry, physics, and biology in our rapidly warming world, but it also raises the question of whether we humans are rational creatures that will take action to avoid our own doom, and the doom of much we know and love, or we are just frogs sitting in the proverbial pot as the water boils and we cook ourselves to death.” 🐸🥵
I won’t summarise the whole 2,913 page report, but the key takeaway is ‘urgency’. Even if the world follows through on its pledges for 2030, we’ll way overshoot our 1.5 degree temperature goal. Limiting warming to 1.5 degrees requires peaking our emissions before 2025 – earlier than what the last Carbon Dispatch suggested!
An interesting tidbit for the finance-minded: there’s an unprecedented amount of capital flowing to clean tech and other climate solutions, but the IPCC finds that to meet our temperature goals, investment requirements this decade are three to six times greater than current levels. “There is a climate financing gap which reflects a persistent misallocation of global capital,” the April report says, noting the importance of government policy in shaping investment incentives. 💰💰💰
For a really nerdy, in-depth summary of the report, Carbon Brief has a great one here.
For a still nerdy but slightly less in-depth view, The Economist has you sorted here.
Where in the world … 🌎
In 1979, in the midst of a global energy crisis, US President Jimmy Carter put some solar panels on the roof of the White House. 😇
Source: Canadian Centre for Architecture
Fred Morse, an engineer who helped install the panels, was there to watch the next US President Ronald Reagan take them down. “We had a new administration that really did not like renewables very much. I don't know if you remember those days when it was called alternative energy and there was something about 'alternative' that did not sit very well,” he told Scientific American in 2010.
Solar finally returned to the White House in the 2000s – President George W. Bush stopped short of putting it on the roof (too much of a statement?), but did install some to heat the residence and pool. The rooftop panels finally returned in 2013, under President Barack Obama.