In my last post looking at the potential for solar energy, I highlighted the drawbacks identified by Euan Mearns and Roger Andrews in their blog Energy Matters. They emphasise the disjoint between when and where renewable energy can be produced and when and where it is needed. The disconnect between production and consumption makes any consideration of levelized cost of energy (LCOE) problematic.
LCOE is the cost to produce energy at a particular place and time; it is not the cost to deliver energy to the consumer at a particular place and time. Accordingly, while renewables have made great strides to match or even undercut their fossil-fuel rivals in terms of cost competitiveness on an LCOE basis (see the chart below) this isn’t enough to allow renewables to rule the world.
Critically, renewables suffer from a feast or famine: throughout the day and over the year, you could be producing too much renewable energy that goes well beyond demand or not enough energy to meet demand. Once you crank up renewables on a much larger extent than now, you get into a world of energy deficits and energy surpluses as shown in the Energy Matters chart below (from here):
Nonetheless, when putting together the chart above, Andrews skips around or simply ignores any counter arguments that could upset his thesis.
Critically, the question of renewable energy intermittency is well-known, but is being tackled by grid operators in a holistic, multi-dimensional manner. There is no silver bullet ready to solve the problem of intermittency; that is, the problem of moving energy through time and space.
Nonetheless, if you are a renewable energy skeptic, you can extract any one solution to the problem of intermittency, deconstruct it and then destroy it. In isolation, this is relatively easy to do, and is a classic straw-man argument. You pick any one solution, crank it up to try to solve the intermittency problem in its entirety, and then rubbish the solution due to the astronomic cost estimate that you produce.
But the solution to the problem of intermittency comes as a package. A range of solutions to the intermittency problem will be rolled out, and no one solution is expected to tackle the problem of intermittency alone. Restated, if each approach is resolving a bite-sized portion of the problem, it only has to be scaled to a far lower size. The range of such solutions could each have a manageable cost, and after being blended together you get to where you want to go: a renewable energy world. Note, I am not saying this is the likely outcome, I am saying that this is a possible outcome.
Furthermore, Tony Seba’s predictions are, obviously, forward-looking. So any analysis must be looking at costs out into the future. And those are not just the costs associated with the generation of renewable energy itself, but also the costs to provide a solution to the intermittency problem going out 10 years or more. As of today, if we add the cost of the package of intermittency solutions, 100% energy generation via renewables comes out a lot more expensive than fossil-fuel energy generation (of course ignoring the cost of climate change). But that says nothing about tomorrow.
What are the partial solutions to the intermittency problem? I would place them into four major categories.
- Overbuild low cost renewables to partially plug the energy deficits
- Move renewable energy through space (transmission)
- Move renewable energy through time (storage)
- Alter the timing of demand to meet supply
These are the topics for my next posts.
P..S. While checking the link to Energy Matters on this post, I was sad to see that Roger Andrews has just passed away. While I don’t agree with everything he wrote, his posts have frequently challenged my beliefs and made me delve a lot deeper into the energy literature. Commiserations to his family; he will be missed by the many who follow the Energy Matters blog.
Risk and Well-Being 
“You pick any one solution, crank it up to try to solve the intermittency problem in its entirety, and then rubbish the solution due to the astronomic cost estimate that you produce.”
This has always been my main problem with the approach at Energy Matters and why I stopped following it a while back.
I’d add a fifth solution to intermittency – go deep on efficiency. You need much less of the other solutions if you cut your energy demand substantially. Perhaps that isn’t enough to merit it being a solution in its own right but in my view it’s critical.
Yes, I think you are right. Although efficiency it is sort of a meta level solution, as it is not specific to solar but relates to any issue of energy scarcity and carbon emissions.
Enjoying this series!
To JamieB’s comment, I read this a few weeks ago, suggests you have a very valid point!
https://www.collaborativefund.com/blog/the-biggest-returns/
“The United States uses 60% less energy per dollar of GDP today than it did in 1950. Globally, it’s dropped 25% since 1990.”
Growth in demand has clearly wiped out any gains, but it will surely have a significant part to play going forward especially if we can keep Growth more in check.
Stupid question, solar gets all the attention but wind seems to have made much bigger strides in market share in U.S. and wind is also a tech that keeps getting better and can often provide green electricity at different times, seasons than peak solar times. Our blizzard in upper Midwest this weekend, with sustained high winds, likely rocked for wind generation.
I know the focus is solar but if wind can get nearly as cheap as quickly and provide power at different times than solar, important part of making solar more cost efficient.
Karen. I would agree. I’ve concentrated on solar because Seba was focussing on solar and basically saying that solar can do all the heavy lifting in terms of taking the world off carbon. I actually think he did this purely for narrative purposes, so when looking at his forecasts for solar it is basically impossible to exclude the impact of wind. I’ll come back to that point.