Author Archives → bjorns

Publication of electric bus & depot model

RouteZero, our tool for simulating the energy consumption of electricbuses on any given bus route and the grid impacts of charging them at a bus depot has been published in a Nature Portfolio special issue https://www.nature.com/articles/s44333-024-00008-2.epdf

The tool is now also availble opensource in its entirity https://github.com/bsgip/RouteZero/

While the easy to use web version remains freely available https://routezero.cecs.anu.edu.au/ has been extended to include Autearoa.

If you’d like to have further routes added to the web version please send me a message. All we need is the gtfs files (which are ubiquotously available).

Hats off once more to Johannes Hendriks for doing the heavy lifting in creating this fantastic tool!

Flat fees for flexible EVs

This study builds upon the recently published Unplugged is inflexible report to explore one avenue by which EV drivers could be incentivised to: 

  1. plug their EVs in for extended durations, and  
  1. permit their vehicles to be charged flexibly.  

While there are many avenues by which this could be done, we here explore the potential for EV drivers to be offered very simple, flat retail offers based solely on how often they plug in their EVs and how much energy their EV consumes. This approach entirely removes considerations of when in the day vehicles are plugged in, which lightens the mental burden on drivers and may contribute to greater acceptance of managed charging. 

This concept is motivated by the belief that creating price-certainty, and ideally cost-certainty, is a core way in which electricity retailers create value for their customers. This EV charging arrangement engages customers (EV drivers) is a quid pro quo where retailers contribute their expertise and diversity of customers to manage pricing risk, and EV drivers contribute the flexibility of their charging demand. 

Our modelling shows that doubling the amount of time EVs are plugged in for reduces the cost of charging by half. To be clear, this requires nothing of EV drivers other than having their EV connected to a charger for longer periods, which enables more flexibly charging behaviour. 

To quantify the risk for retailers we conduct a statistical analysis in terms of the cost of EV charging per day or per kWh. This suggests that offering a fixed price per day may go beyond retailers’ risk appetite, making a fixed price per kWh the more attractive option. This is likely also fairer for customers as it charges for the precise amount of energy used. 

The addition of vehicle-to-grid increases the benefits of longer plug-in times by facilitating market arbitrage. Vehicles that are driven less than 40km per day and are plugged in to chargers for more than 8 hours a day (with vehicle-to-grid) can, on average, be charged at zero or negative cost. 

While outside of the scope of this study, we note that this same tariff concept (and simulation model) could be applied matching flexible EV charging with the generation of a collection of wind or solar farms. This would provide another way for a retailer to manage/fix their price exposure while simultaneously creating value for customers by charging vehicles with zero emissions power. 

Full report below

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Unplugged is inflexible – How drivers’ plug in behaviour determines the flexibility of electric vehicle (dis)charging

In a neat little project for the ACT Government I analyse the (IMO oft overlooked) critical step of when EV drivers plug in their vehicles. If they’re not plugged in for substantially longer than required for charging then EVs are not the fabulously flexible load that they could be.

202406-Unplugged-is-inflexibleDownload

Watt equity? Australians deserve a Basic Energy Right

This essay was first published in Australian Quarterly 95.3, Australia’s Longest running public affairs magazine, published by Australian Institute for Policy and Science https://aips.net.au/aq-magazine/current-edition/

AQ-95.3-JUL-SEP-2024-Watt-EquityDownload

Within the energy industry there is a popular, feel-good refrain that the energy transition will deliver a system that is ‘democratised’, in addition to being ‘decarbonised’, ‘digitised’, and ‘decentralised’. Here democratised is used as an umbrella term for a broad suite of desirable values: fair, just, equitable. Yet the way in which democratisation is envisioned to occur is, in contrast, blinkered – households are seen to gain political power as a consequence of their generating and controlling electrical power from rooftop solar, batteries, and electric vehicles – but what about those without?

This prevailing narrative of democratisation overlooks, amongst other things, the connection between privilege and ownership of these technologies, and the structural realities of social, as well as techno-economic, power. In particular, it ignores the systemic effects of managing energy through markets and, consequently, ignoring energy’s role as an essential service underpinning modern life.

The starting point of this essay is that the energy transition is not on track to improve equity. This is because equity will only be improved if it is prioritised above competing values, such as profit, in the millions of design choices that constitute the transition.

Such prioritisation is impossible within the existing (artificially) constrained policy landscape, in which the only options are those within the framework of indistinguishable individuals interacting through a market. This eliminates any space for unequal redistribution in recognition of the differing circumstances within the collective, and thereby contributions towards equity.

Progress towards equity rests on expanding the policy imagination. This essay offers one such suggestion: the establishment of a Basic Energy Right that provides all households with a modest amount of energy free of charge to meet their essential needs.

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Bean nuclei

There once was a bean farmer called P. For years, he’d supplied his local shops and cafes with tasty black beans. But then along came a new farmer whose green beans were much cheaper, and what’s more didn’t make people fart.

Everyone in town was excited to switch to these new cheap fart-free green beans. Farmer P was facing ruin.

So P decided to remind everyone that there was also a third type of bean that they should consider. This is an exotic purple bean that no local had ever tried.

Now P knew that these pink beans were expensive, hard to grow, and were suspected of making people’s hair fall out. No customers was going to choose the pink beans over the cheap, clean green beans.

But by making his customers spend time researching these pink beans P hoped to sell them another season or two of his old familiar black beans.

—
Inspired by question from students at Cringila Public School as part of a DeadlyScience session | Image from deepai.org

Ignore variability, overestimate hydrogen production – Quantifying the effects of electrolyzer efficiency curves on hydrogen production from renewable energy sources

In this new paper with Dan Virah-Sawmy and Fiona J Beck we show that neglecting the variable electrolyzer efficiency, as is commonly done in studies of green hydrogen, leads to significant overestimation of hydrogen production in the range of 5–24%

https://www.sciencedirect.com/science/article/pii/S0360319924020676

Abstract

This study investigates the impact of including (or neglecting) the variable efficiency of hydrogen electrolyzers as a function of operating power in the modelling of green hydrogen produced from variable renewable energy sources. Results show that neglecting the variable electrolyzer efficiency, as is commonly done in studies of green hydrogen, leads to significant overestimation of hydrogen production in the range of 5–24%. The effects of the time resolution used in models are also investigated, as well as the impact of including the option for the electrolyzer to switch to stand-by mode instead of powering down and electrolyzer ramp rate constraints. Results indicate that these have a minor effect on overall hydrogen production, with the use of hour resolution data leading to overestimation in the range of 0.2–2%, relative to using 5-min data. This study used data from three solar farms and three wind in Australia, from which it is observed that wind farms produced 55% more hydrogen than the solar farms. The results in this study highlight the critical importance of including the variable efficiency of electrolyzers in the modelling of green hydrogen production. As this industry scales, continuing to neglect this effect would lead to the overestimation of hydrogen production by tens of megatonnes.

SwitchedOn podcast on Energy Equity

Delighted to be on RenewEconomy & Boundless Earth SwitchedOn podcast kicking off a discussion of how to *truly* improve energy equity https://reneweconomy.com.au/switchedon-podcast-free-electricity-to-cover-essential-needs/

“A popular refrain of the renewable energy transition is it will deliver an energy system that is more democratic, as well as decarbonised. That the political power of generating energy will shift from big power companies to households, as a result of us being able to generate and control electrical power from our rooftop solar, batteries, electric vehicles, etc.

But this decentralised, democratic narrative isn’t a foregone conclusion…”

EnergiZines: 43 personal interpretations of the energy transition

Last year I had the pleasure of working with the creative team of Engaged ANU (The Australian National University), Brad Riley and the inspiring Tristan Schultz on a pretty out there engagement that we called “EnergiZine – Nurturing Energy Transitions”. We’ve just uploaded the Zines created in these workshops for all to read and be inspired by https://dev.mtchl.net/energizine/viewer/

They represent 43 members of the public’s personal takes on the energy transition story, where it comes from and where it should lead to.

This short video gives a sense of what the evenings were like https://vimeo.com/847972505