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The Slow Death of Energy Crops

image credit: Fraunhofer

I live in a rural area where the stable farming income comes from energy crops such as rape seed and corn, the former being used for biodiesel and the latter for biogas production. Both have been heavily supported by government regulation but when current subsidy regimes run their course, the farmers in the region will, by necessity, need to find other uses for their land. The reason is down to a combination of Science, Mathematics, Economics and Technology.

Science has led to a greater understanding of how important the sun’s energy is to both our planet and to our daily lives. Nearly all useful energy on our planet, with very minor exceptions, comes from the sun. Without the sun we would have no plants, no trees, no animals, no food and no biomass feedstock. The infinite process of photosynthesis has left us with a valuable legacy of fossil fuels such as coal, oil and natural gas. Yet enough solar energy falls on the surface of our planet each day to surpass our current energy needs by 10,000 times! The challenge is how best to harness this energy.

This is where Mathematics come in. The issue with photosynthesis is that it is a highly inefficient way of capturing the sun’s energy. The process of creating useful energy, such as bio-ethanol or bio-diesel, biogas or electricity from such energy crops, is so poor and requires so much land that Europe could cover the whole continent with energy crops and still not meet its own energy needs. More specifically, my local 1MW biogas power station uses circa 12,000 tonnes of biomass per year which is produced on 300 hectares of land. By contrast, if only 6 hectares of that land were covered in solar panels it would produce as much energy as that biogas power station and it would do so at half the cost! 

In comes Economics. It does not matter whether the energy crops are used to produce electricity or biofuels for transport purposes, the economics are much more expensive than fossil fuel alternatives. On the other hand, using Solar to produce electricity for the grid is already cheaper than using any form of biomass and going forward, as solar PV costs continue to fall, it will be cheaper to use that electricity to create liquid fuels and even chemicals like ammonia. Energy crops, in stark contrast, do not have the same experience curve effects that solar have. Yields are increasing thanks to advances in biotechnology but not near the rates we are seeing with solar.

Which brings us to Technology and energy storage in particular. One of the major benefits of energy crops is that they can be easily and cost effectively stored. Ethanol can be stored in a tank, for instance, wood in a shed or biogas in the gas grid. Meanwhile electricity produced from the sun either needs to be used immediately or converted into another form of energy such as water stored behind a dam or chemical energy in the form of a battery or hydrogen. However, most of the required infrastructure is not in place today. As we roll out EVs with their mobile batteries we will go a long way towards putting this infrastructure in place. In addition, the maturing of technologies such as power to gas, power to liquids and power to chemicals could radically change this picture.

The implications of this are that we will likely see the demise of energy crops over the coming years. Which begs the question what other uses could farmers find for their land? Perhaps they should strategically embrace the sun and in doing so, make hay while the sun shines.

Gerard Reid's picture

Thank Gerard for the Post!

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Matt Chester's picture
Matt Chester on Nov 18, 2019 5:18 pm GMT

Farmers looking to embrace the value their land can get via solar can also get pretty creative, as others are already doing:

At a recent solar energy conference in Minneapolis, attendees unwound at happy hour tasting free pints of a local honey-based India pale ale called “Solarama Crush.” Minnesota-based 56 Brewing makes the smooth IPA using honey from hives located on solar farms outside the Twin Cities.

Honey producers Travis and Chiara Bolton keep bees at three solar farms where developers seeded native plants underneath and around panels. “The advantage to these sites is that they are intentionally planted for pollinators,” says Travis Bolton. “At these sites, they’re really trying to get them back to a native prairie, and that’s a benefit to us.”

Gerard Reid's picture
Gerard Reid on Nov 18, 2019 6:59 pm GMT

I'm off to Minneapolis on Wednesday!

Matt Chester's picture
Matt Chester on Nov 18, 2019 10:24 pm GMT

Guess you'll have to keep an eye out for Solarama Crush!

Bob Meinetz's picture
Bob Meinetz on Nov 18, 2019 5:38 pm GMT

"Meanwhile electricity produced from the sun either needs to be used immediately or converted into another form of energy such as water stored behind a dam or chemical energy in the form of a battery or hydrogen. However, most of the required infrastructure is not in place today."

Most of the required infrastructure is not in place today, Gerard, for want of a legitimate reason. There is none, from either the realms of Science, Mathematics, Economics, nor Technology, which supports the notion energy from the sun (which currently generates less than 2% of U.S. electricity) will ever be capable of generating enough electricity to replace fossil fuels. Storage, notwithstanding.

So instead, proponents resort to justification from the realms of Religion, Quackery, Fraud, and Fake Science - where justification for anything is never in short supply.

Gerard Reid's picture
Gerard Reid on Nov 18, 2019 7:00 pm GMT

What infrastructure is needed? There is grid everywhere? 

Bob Meinetz's picture
Bob Meinetz on Nov 18, 2019 8:36 pm GMT

Not sure if you're referring to batteries, dams and hydrogen as infrastructure, but traditional grids are of radial topology, designed specifically to transfer electricity from central generating plants outward, with more robust pathways used to transmit electricity to population centers.

There seems to be a popular misconception that "once the wires are there, we can transmit electricity with equal facility from anywhere to everywhere." This is nonsense. The problem of avoiding grid constraints - logjams of electrical energy which would threaten the entire grid - can be likened to attaching  a 3,500W battery to the light socket in your bedroom, then trying to direct energy backwards over the line to power the oven in your kitchen (it would quickly trip a breaker, but possibly start a fire first).

Infrastructure wasn' t built that way for a reason - it made sense. Centralized electricity generation, spread by a radial-topology grid, was the most efficient and inexpensive way to transmit electrical energy to the greatest number of people.

In 2012 Nobel-prizewinning chemist Hartmut Michel wrote The Nonsense of Biofuels, an editorial which is basically a validation of your comments on the inefficiency of photosynthesis. For "What other uses could farmers find for their land?", plant-based meats offer nearly unlimited potential. As technology improves there is a lucrative international market for soy- and pea-based meat, without the land and energy required to raise livestock. Personally, I had to experience an "Impossible Burger" to believe it (I'm a believer).

Gerard Reid's picture
Gerard Reid on Nov 19, 2019 4:58 pm GMT

I agree with you Bob on plant based diet! I come from Ireland where 1/3 of greenhouse gas emissions are caused by cattle...that is not an easy transition!

Matt Chester's picture
Matt Chester on Nov 19, 2019 5:18 pm GMT

'Meatless Mondays' worked as a terrific transition for me-- never thought I'd go vegetarian, but here I am!

Laurent Segalen's picture
Laurent Segalen on Nov 18, 2019 6:17 pm GMT

Totally agree with you, Gerard Reid

The support mechanisms won’t be there forever. Those policies were designed in a bygone “peak oil” era, before renewables, cheap gas, and EVs.

Gerard Reid's picture
Gerard Reid on Nov 27, 2019 7:47 am GMT

Well said!

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