More ways to create energy, P2P energy trading and carbon credits on the blockchain

I started Decarb Diary as a place to publicly capture and share what I learn as I enter into a rapid immersion in climate, energy, decarbonisation, etc, over a 3-6 month period to find the most painful problems that I have the skills to help solve. Ultimately I hope this will lead to starting a globally scalable business that will have real impact in the world. Learn more here.

Key Insights and Takeaways:

• I continue to find new ways that energy can be sourced, created and cooled - this week looking at enhanced geothermal, piezoelectricity (created via pressure), and supercritical CO2.
• On geothermal, I'm really starting to think it's the holy grail of renewables - it's 24/7, carbon-free, will never run out, and it's cheap and easy to get!
• The company doing enhanced geothermal took technology from gas fracking and applied it to geothermal, saving significant time, money and effort and increasing output. I have always believed some of the best innovation comes from taking something from industry and applying it to another.
• The "traditional" way that energy is bought and sold (you pick one retailer and pay flat rates) is quickly going out of date in favour of new models - I was told of a company doing peer-to-peer trading, which means you could literally buy or sell your energy with another specific household.
• Continuing the innovation, I was also told of a company who has put Australian Carbon Credits (ACCUs) on the blockchain, creating a digital 'version' of an ACCU that can be traded like cryptocurrency (or similar to how you trade shares).

New content this week

• Discover what Enhanced Geothermal
• Why supercritical carbon dioxide can replace water
• What is piezoelectricity
• A peer-to-peer electricity market
• A blockchain trading platform for carbon credits
• Tracking Australia's energy transition on the OpenNEM tracker

From Enhanced Rock Weathering (covered last issue) to Enhanced Geothermal

From the Volts podcast episode: Catching Up With Enhanced Geothermal.

This episode host david roberts spoke with Tim Latimer, CEO of a startup called Fervo Energy , who have been working to transfer the technology advancements made in gas fracking over to geothermal energy production.

An Enhanced Geothermal System (EGS) is basically drilling a deep well (around a few thousand metres) into hot rock, where it gets hotter the deeper you go, pumping high-pressure water into the rock to open it up, and then circulating water through it to create steam to power turbines up above.

The “enhanced” part of this is where you use technology to open up the rocks, while a “normal” geothermal system relies on naturally occurring hot water or steam within rock formations.

And Fervo’s innovation means they can drill down and then go sideways another 1-2 kms.

Here’s why this is cool:

• It gets harder to keep drilling vertically, but when you turn horizontally you get that same heat for the whole length,
• Drilling straight down means you need to make sure you’re digging in the right spot, otherwise you need to dig another hole; Fervo’s method can dig down and then in any direction, increasing the chance of hitting the hot spots,
• This has brought down drilling costs by 70%, doubled the flow rate of water and produced 10x more output compared to other EGS companies!

Geothermal doesn’t seem to be all that well-known and it only makes up about 1% of the world’s renewable energy, but I think it’s the holy grail in renewable energy - it’s 24/7 (the Earth is always hot), it’s carbon-free, it’s quick to build (approx 17 days to dig the hole) and it’s proven tech (it’s been around for over 100 years).

Apparently you could extract energy from a geothermal hole for about 30 years. It will take about 30 years to get hot enough to go again, but obviously that’s where you dig another hole while you wait. And some calculations done show there’s enough energy for 17 BILLION years (the sun will only last for another 5 billion), which makes this unlimited!

Supercritical Carbon Dioxide (sCO2)

This is really cool - sCO? is CO? that has been heated and pressurized beyond its critical point (about 31°C and 73 atmospheres of pressure). In this state, it behaves like both a gas and a liquid - it flows like a gas but has the density of a liquid.

And its relevance here is that it can be used instead of water as a working fluid in power plants, replacing steam.

Normally, power plants use water to create steam, which spins turbines to generate electricity. sCO? can be used instead of water to drive turbines more efficiently. It expands rapidly like steam but at a much lower temperature and pressure, making the process more efficient.

So you get higher efficiency (more electricity from the same amount of energy), with smaller & cheaper equipment (because it works at lower temps and pressures), with less water usage and lower overall emissions (due to higher efficiency of the plant).

What the heck is Piezoelectricity

Piezoelectricity is the ability of certain materials to produce electricity when they are squeezed or compressed.

It’s already used in things like electric lighters, inkjet printers and quartz watches.

But why this is relevant and pretty cool is that Japan is trialling piezoelectric footpaths/walkways where as people step on special tiles/pavers, it generates electricity - literally talking walking into electricity!

It’s probably not all that practical at this stage - it has high installation costs and low individual electricity generation per step - though in a really busy area like the Shibuya train station, this is powering their LED displays, information boards and other low-energy devices.

And if you’re wondering, “Piezo” comes from the Greek piézō which means "to squeeze or press".

Check it out this 30 second video here about how it's used in Japan.

LocalVolts - P2P Electricity

Localvolts Pty Ltd is an Australian peer-to-peer electricity company that started in the mid 2010s. Households and businesses can sign up to buy electricity based on their preferences from the market, or sell excess energy they generate into that market.

This can be used to trade energy between houses on the same street or within a neighbourhood, or to any participating member on the platform.

Interestingly, this could be a way for landlords to potentially use their own solar power/ battery storage for their investment properties. If the landlord’s own property has solar and battery, then they could sell that to their own investment property.

https://localvolts.com/

Beta Carbon - blockchain trading platform for ACCUs

This is an interesting one - BetaCarbon- Australian Carbon Token is a blockchain-based company that allows you to trade Australian Carbon Credits.

A carbon credit is equivalent to the removal or avoidance of 1 tonne of CO2 being released into the atmosphere. Carbon credits are created through projects that capture GHGs from the atmosphere, such as planting trees. These credits can then be bought and sold in the carbon markets, typically by businesses who use these to offset their emissions (eg if they emitted 3 tonnes of CO2, then they’d need to buy 3 carbon credits).

This company has put these on the Ethereum blockchain, called Australian Carbon Tokens (BCAU). In this case, the 1x BCAU token represents 1kg of CO2. This also means anyone (ie. retail investors) can buy, sell and trade carbon tokens, or hang onto them as a store of value.

As of 17/2 it was trading at $0.036714 per token.

Super cool.

https://www.betacarbon.com/

OpenNEM - Australia’s energy transition tracker

Thought this was a nice one - a simple platform where you can see how Australia is tracking in its transition to renewables.

As of Jan 2025, about 40% of energy was renewable, with 60% coming from coal, but you can easily see how it’s powering towards more renewables (the graph starts at the year 2000).

It also has breakdowns by day, by energy type, by state, as well as projections through to 2050 based on low, medium and high-uptake scenarios.

You can also see every renewable and non-renewable power plant across the country that is operating or planned.

https://openelectricity.org.au/

I encourage you to reach out if:

• I've said something wrong or partially wrong,
• there's an additional thing I should know about,
• you think it would be valuable to talk to you, or
• you know someone I should talk to!

Note though, if you don't believe in climate change, please don't spread your misinformation here. My newsletters are not a debate about whether climate change is real - that was settled long ago by actual science, with plenty of overwhelming evidence (and a good dose of common sense).

Cheers,

Dan