The Problems with Renewables
It is a widely accepted fact that human caused climate change is occurring. Humanity’s endless thirst for energy is causing a rapid increase in the parts-per-million of CO2 in the atmosphere, contributing to global warming, biodiversity loss, rising sea levels and myriad other pretty undesirable things to be happening on the planet we live on.
I should be clear here: In this article when I’m referring to renewables, I’m talking about the two predominant renewables that you might think of – wind and solar. Tidal, hydrothermal and hydroelectric power are much more useful and reliable but are also less commonplace. It’s difficult to build them where there’s no tides or rivers. I’ll be comparing some of the issues between fossil fuels and wind and solar. Now, before you read on, have a guess in how many years we’ll have globally depleted all of our coal, oil and gas reserves. 20? 100? 500? Never?
To start with, a reliance on fossil fuels poses some big non-environmental problems. Firstly, even if these forms of energy did not produce CO2, we are using them at a much faster rate than they are replenishing – estimates predict that we’re going to run out of oil and gas within 30-40 years and coal after around 100 years. [2,3] I bet that’s sooner than you thought, I know it was sooner than I did! I have a wish (hopefully not too uniquely) to leave future generations a planet that is better and healthier than the one we currently inhabit. As abstract as it sounds, that future is determined by the individual actions, beliefs and support of many billions of people. One of which is you.
Secondly, for countries without access to domestic fossil fuels this means an increasing reliance on countries that do. I won’t make any political comments on this point but… well, it seems safest to depend on as few external countries as possible, in my opinion.
Goldilocks and the Wind Turbines
Two of the most poignant problems with wind and solar is their reliability and efficiency. For example, what maximum wind speed do you think most wind turbines can operate up to? Off-shore wind turbines will generally shut down at wind speeds greater than 50 mph and produce no electricity. How about at wind speeds below 8 mph? Yep, also none. The upper limit also varies with different turbines, and is generally lower for on-shore turbines. Because of this, the placement of turbines in areas that commonly have appropriate windspeed is necessary, hence the abundance of off-shore turbines. The percentage of time that the wind turbine is producing electricity is called the capacity factor. In the UK the capacity factor ranges between 30 and 50 %. [4] Solar panels experience an even worse situation having a capacity factor of around 10-20% [5,6].
When wind turbines can produce energy their efficiency is subject to the Betz Limit which states that the maximum efficiency of a wind turbine is 59.3% and in reality most turbines operate lower than this due to mechanical losses of energy. So a large percentage of the total wind energy is missed from the get-go. Not a strong start.
Energy O’Clock
On a surface level this may not seem like a problem. Taking the UK as an example, the national grid does a pretty swell job of telling energy companies how much electricity they should be adding to the grid and that’s because the requirement for energy is pretty predictable throughout the day (think when you have your first cup of coffee or cook dinner) as you can see from the graph below. You can also see how much energy and from what sources the UK is getting its energy at this exact second from the National Grid here. Check it during a stormy cloudy day and see how great renewables are doing then…
So, if we’re relying on renewable energy and at 5:30 we’re all good, maybe its a little windy and we’ve got enough energy to distribute to everyone that needs it. Then, everyone gets up to work another day, well it would be pretty wishful thinking to just hope the wind to suddenly pick up. In reality the sudden surge in demand has to be met by another means and, no prizes if you guessed correctly, this is normally an oil or gas plant [7]
Wait, so James, are you saying that increasing energy from renewables also increases energy from fossil fuels? YES, THAT IS EXACTLY WHAT I’M SAYING.
In 2015 Germany began decommissioning nuclear power stations to focus on the development on renewables to meet climate targets. In the year, nuclear energy reduced by 5.8% while renewables and natural gas increased by 10.5% and 5.0% respectively. Overall, the CO2 emissions of the country increased that year by 1.5% and also increased the following year, despite the introduction of renewables and also of reducing the dependence on lignite coal plants (a highly polluting, low energy density type of coal). In the years following, the CO2 emissions from energy production have declined however [8].
How do you like your birds? Blended or fried?
One tragic (and sadly, ironic) issue facing wind and solar is the harm they cause to wildlife. Generally people are in support of them as ‘green’ forms of energy that must be good for the environment. When in actual fact, birds are getting fried by solar panels or diced by wind turbines all the time. Estimates for the number of birds killed per year in the UK sits between 10,000 and 100,000 (i.e. nobdoy is that certain) [9] . One argument you might propose against this is that millions of birds are killed every year by house cats, the smaller number killed by turbines and solar isn’t really comparable. Well. in sheer quantitty this is true, but house cats don’t kill birds of prey and other endangered species, whereas wind turbines don’t discriminate. For example, the Ivanpah solar farm in US leads to 6000 burnt birds every year. [10] Note that one study found that 16 out of thr 18 observed species recovered in number after the installation of the turbines and suggested that they can learn to avoid the turbines [11].
“Okay well, maybe wind and solar are bad for wildlife, but at least building and demolishing them is pretty green”. Hmm. Sadly not. It is understandable to think that utilising wind and solar means less mining for mineral and materials compared to coal, gas or nuclear but this is simply not the case, as is shown below.
So this has been a brief introduction to some of the problems with wind and solar. Don’t get me wrong, I believe they have a place in the energy supply but not that they are the panacea for our energy problems. In the next post I’ll compare them more with nuclear power as well as give more of my opinion of how they should work alongside nuclear and other renewables. Let me know what you think. 🙂
[1] – https://climateactiontracker.org/global/temperatures
[2] – Shafiee, S. and Topal, E. (2008) ‘When will fossil fuel reserves be diminished?’
[3] – https://link.springer.com/content/pdf/10.1007/s11053-016-9307-2.pdf
[4] – https://energynumbers.info/uk-offshore-wind-capacity-factors
[5] – https://www.iea.org/data-and-statistics/charts/average-annual-capacity-factors-by-technology-2018
[6] – https://www.statista.com/statistics/555697/solar-electricity-load-factor-uk/
[7] – Boyle, G. (Ed.). (2009). Renewable electricity and the grid: the challenge of variability. Routledge.
[8] – https://www.cleanenergywire.org/news/german-co2-emissions-rise-2015-despite-renewables-surge
[9] – https://www.lse.ac.uk/GranthamInstitute/wp-content/uploads/2014/03/PB-onshore-wind-energy-UK.pdf
[10] – https://www.latimes.com/local/california/la-me-solar-bird-deaths-20160831-snap-story.html
[11] – Pearce-Higgins, J.W., et al. (2012), Greater impacts of wind farms on bird populations during construction than subsequent operation: results of a multi-site and multi-species analysis. Journal of Applied Ecology, 49: 386-394.
[12] – https://www.energy.gov/index.php/quadrennial-technology-review-2015
Atomic Thoughts 