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Michael de Podesta @protons4b.bsky.social · 4d

I looked at that document but I need to read it again. The condensation efficiency specification makes sense, but I could not understand the energy efficiency specification at all.

It didn't seem to mention the latent heat of water anywhere? That's nuts!

I will read it again this morning

Michael de Podesta @protons4b.bsky.social · 4d

Yes. In Experiment#2 the clothes weighed 7 grams less at the end than at the beginning. I am pretty sure that was due to entrained moisture - or different levels of dryness.

Michael de Podesta @protons4b.bsky.social · 4d

That's interesting too! I may need to develop my measurement protocol!

Michael de Podesta @protons4b.bsky.social · 4d

@wiilp.bsky.social Oh! Thanks for this information. I will attempt to process it all and get back to you!

Friends, recently I have been continuing to avoid thinking about EPCs. I have instead been thinking about washing my dirty laundry in public. Or more precisely, drying my laundry in public. Unless …

Michael de Podesta @protons4b.bsky.social · 5d

protonsforbreakfast.wordpress.com/2025/10/05/t...

I made some measurements on the efficiency of my condenser tumble dryer.

I found it was surprisingly efficient, with the most powerful energy saving feature being the "wetness: sensor that prevents "over drying".

Tumble Dryer Efficiency

Friends, when my now wife and I first moved in together, we bought a cook book as a symbol of our domestic focus. It was a book by Delia Smith and we were attracted by the fact that the cover showe…

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Michael de Podesta @protons4b.bsky.social · 5d

Wherever you go... there you are.

Michael de Podesta @protons4b.bsky.social · 11d

protonsforbreakfast.wordpress.com/2025/09/29/b...

Have you ever wondered how those automatic egg boilers work?

I carried out some eggsperiments, recording: the mass of water remaining versus time; the time to switch off; and the internal temperature of an egg versus time.

Enjoy!

“Boiling” an egg

The Looming Disaster Under America’s Biggest Oil Field

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Michael de Podesta @protons4b.bsky.social · 17d

youtu.be/IgSN8mM6IJM

Can you imagine if renewable technologies generated earthquakes or toxic wastewater?

How does oil and gas get away with it?

YouTube video by Bloomberg Originals

youtu.be

EPCs: An Open Letter to Stuart Fairlie

Michael de Podesta @protons4b.bsky.social · 21d

protonsforbreakfast.wordpress.com/2025/09/19/e...

Elmhurst Energy trained the assessor and approved an #EPC on my home which was in error by 21 points (73C vs 94D). Errors like this are probably rare, but smaller errors of ~10 points are probably common.

Here's 4 suggestions to improve matters.

Friends, at one point on my recent EPC (Energy Performance Certificate) adventure, I was a speaker on Radio 4’s You and Yours along with Stuart Fairlie, the Group CEO of Elmhurst Energy. Elmh…

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Michael de Podesta @protons4b.bsky.social · 21d

soundcloud.com/dylanesque19...

You are right. Here's a song I imagined singing in a few years time, but it already makes sense now.

"I long for the long rainy summers
I used to know in my youth
Long cold rainy summers
I wish you could know them too."

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Michael de Podesta @protons4b.bsky.social · 26d

Now correctly rendered.

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Michael de Podesta @protons4b.bsky.social · 26d

Here's my month by month costs for the last 4 years and the annual carbon dioxide emissions. The yellow shows the avoided emissions from exported electricity.

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Michael de Podesta @protons4b.bsky.social · 28d

Typo: "Monopiles": very confusing!

Michael de Podesta @protons4b.bsky.social · Sep 4

So at higher temperatures one would need to vacuum insulate using multiple reflector layers.

Best wishes

Michael

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Michael de Podesta @protons4b.bsky.social · Sep 4

If I recall, I just used standard thermal conductivity figures - probably looked up from The Engineering Toolbox.

Thinking back to my working days 500 °C radiation is not that much of a problem in terms of radiative losses. But as one approaches 1000 °C materials like alumina become translucent.

Varanto - The Cavern Thermal Energy Storage - Vantaan Energia

Michael de Podesta @protons4b.bsky.social · Sep 4

Yes.

At the time this was touted as inter seasonal storage, but 100 MWh is not a great deal of heat considered in comparison with annual household heating demand of somewhere between 8 MWh and 16 MWh: it 6 to 12 dwellings.

Michael de Podesta @protons4b.bsky.social · Sep 4

Sandy, Good Morning. Indeed. Here is perhaps the most extreme example of that principle, also in Finland. This uses water stored underground. The pressure 50 m underground is sufficient to suppress boiling and allow storage at 140 °C (IIRC).

www.vantaanenergia.fi/en/about-us/...

The World's Largest Cavern Thermal Energy Storage

www.vantaanenergia.fi

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Michael de Podesta @protons4b.bsky.social · Sep 1

See also this astonishing underground thermal storage project in Finland using water.

www.vantaanenergia.fi/en/about-us/...

Varanto - The Cavern Thermal Energy Storage - Vantaan Energia

The World's Largest Cavern Thermal Energy Storage

www.vantaanenergia.fi

A Sand Battery: Not obviously a great idea.

Michael de Podesta @protons4b.bsky.social · Sep 1

protonsforbreakfast.wordpress.com/2022/07/21/a...

It's interesting to see how this project has developed.

I wrote this article 3 years ago when it was being described as inter seasonal storage.

In the article I look at the pros and cons of using water or sand for thermal storage.

Friends, a few weeks ago I was asked by several people whether I had heard about the latest ‘sand battery’? I had never heard of any such thing. Most people asking me had come across th…

Friends, the unit of energy used for most domestic energy purposes is the kilowatt hour (kWh): it’s the unit in which we are billed for energy use, and in terms of domestic energy consumption…

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Michael de Podesta @protons4b.bsky.social · Aug 31

protonsforbreakfast.wordpress.com/2025/08/31/o...

When discussing domestic energy matters such as heating or lighting, we think of a kilowatt hour as a small amount of energy. But in human terms, one kilowatt hour is a *massive* amount of energy.

One kilowatt hour (kWh)

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Michael de Podesta @protons4b.bsky.social · Aug 19

well said.

The Green Shipping Fuel Everyone’s Betting On (But Might Regret)

Michael de Podesta @protons4b.bsky.social · Aug 11

youtu.be/EqupcBoH3hQ

The future of Green Shipping is still very unclear. In this video Rosie Barnes (the Rosie in 'Engineering with Rosie) goes through the possibilities with her usual acumen.

It's a tough one...

YouTube video by Engineering with Rosie

youtu.be

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Michael de Podesta @protons4b.bsky.social · Aug 9

Will: Thanks for these comments. They are very helpful.

Michael de Podesta @protons4b.bsky.social · Aug 9

Indeed. I live and learn!