Guillaume Rossolini

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199 Following
4.4K Posts

Apparently, such a system would cost well over the current cost of the property, weigh several dozen tons, take up even more space than I thought, AND make as much noise as legally allowed (that’s <65 dB per module, of which there would be a few dozens)

I’m annoyed that this isn’t usually part of the discussion and I’m even more convinced that grid scale batteries are not viable as a commercial service

… which kind of validates my thinking that “virtual battery” services aren’t batteries in any technical capacity

What gives? Where am I wrong?

#GridBattery #EnergyTransition #ElectricityMarket #VirtualBattery

I have a #coldframe made of perspex and wood which due to its location gets a lot of sun in the morning, I've added some temperature sensors and it can get temps of over 40C at times, this is only for 30-60mins and then it gets a bit of shade and cools down.

I'd like to try and take advantage of this burst of heat but spread it during the day - so Mastodon friends - would adding some thermal mass help, perhaps a plastic bottle of water painted black?

What's nice is that I have sensors so should be able to monitor effectiveness!

#diy
#maker
#gardening
#greenhouse

A few quick calculations that I’m probably getting wrong

handling summer spikes

1500 kWh in a summer month according to the simulations above, that’s 50 kWh per day

If I wanted to ensure that all my production went to the grid, including on the days that every other solar panel in the country is also producing while no one is using much energy, and as a result the grid isn’t accepting input in the afternoon

… then the battery capacity that I’d need would be of the order of 50 kWh, so that I could offload at night (and assuming that few people did the same)

handling winter spikes

Similarly, if I wanted to be fully autonomous by using only my own energy, stored in the summer for discharge in the winter

… Then I’d need hundreds of kWh of battery capacity, probably 3000 kWh at least, which sounds positively stupid

And I’d run into a lot of different issues:

  • space, volume, weight (probably comparable to that of the house itself)
  • regulatory & safety concerns, fire prevention
  • maintenance, servicing contractors
  • cost (probably on par with the entire property, plus ongoing)

conclusions

This is stupid and I don’t understand how grid-scale batteries are a business model that makes sense

I’m trying to understand what everyone is saying about energy production via photovoltaics and how I might do it too (or not).

Attached are two simulations, done six months apart by different companies.

[TL;DR] MyLight150 was saying in late 2024 that their customers could expect their photovoltaics to pay for themselves within 7 years. The quote that I got last November, barely a year later, upped that number to 12 years.

First simulation

This first quote was done remotely. Its purpose was for me to get a general idea of the energy production I could possibly expect. The tools used to make the sim might be aware of the French grid or they might not. The numbers seem to hold up well.

This proposal was meant for my roof, which faces east/west. They suggested 7.5 kWc and a yearly production of about 10 MWh, which is just about my consumption as well.

I understand why the graph looks so clean, since it’s simply a formula applied to averaged monthly radiation levels in my area, with various debuffs taken into account (tilt, orientation etc).

Second simulation

The second quote was done by a local business and is definitely aware of the French grid and its limits.

This proposal includes my usage patterns and is meant to avoid the roof, instead using the garden area and a new support structure allowing for south facing panels. This quote targets 7.2 kWc and a yearly production of 8.2 MWh.

I understand why the graph looks more chaotic, since it (presumably) takes into account the % of time when the grid is unable to accept energy at the time it is being produced, and that energy is lost. It’s probably more realistic than the first sim.

the silly system in France

Our National historic energy provider, called EDF, produces electricity mainly from nuclear but also some dams. Our grid is as decarbonated as can be.

ElectricityMaps Says our mix is 97% low carbon and 30% renewable.

The thing is, that kind of mix didn’t happen easily. EDF invested heavily while it was a monopoly under the control of the government. Then one day, it got privatized. Then another day, the Europe tried to incentivize competition. The way they went about it was to require EDF to sell a portion of its production to third parties, at no additional cost.

So now, a chunk of the energy produced by EDF is sold to startups who then apply small margins before selling it at (lower than market) cost to consumers. They don’t have to invest in infrastructure and EDF can’t capitalize on its own production.

the French solution to the winter/summer discrepancy

We don’t have “net metering” here. We do have the option to sell everything (or only sell the surplus) to the national provider, called EDF OA, at the rate of about €0.04 / kWh.

There are also several independent companies trying to market themselves as “virtual batteries”, essentially what the US would think of as net metering, but with more fees. I’ve come across MyLight150 and Urban Solar for this.

Apparently, there’s a fee that applies to any energy transfer on the grid, regardless of the direction. All told, MyLight150 seems to charge almost €0.10 / kWh (taxes included), while Urban Solar says €0,05 / kWh (without taxes).

my newbie thoughts on this system

So I’d essentially be paying for them to sell my energy to others.

In their own words, they rely on their wide range of customers to be able to ferry the energy around. I’m not certain how they produce the missing energy in the winter, they don’t address that. I do know that in the summer, when the excess energy can’t go anywhere or the grid is close to overloading, they just don’t take it.

They call themselves batteries but they don’t actually invest in any storage infrastructure. They aren’t part of the solution at all.

The future is not bright…

#EnergyTransition #ElectricityMarket #RenewableEnergy

The world's first hydrogen-powered hotel opened its doors in the town of Namie, Fukushima Prefecture, on Wednesday. https://www.japantimes.co.jp/news/2026/03/26/japan/japan-fukushima-hydrogen-hotel/?utm_medium=Social&utm_source=mastodon #japan #fukushima #hydrogen #hotels #renewables
World's first hydrogen-powered hotel opens in Fukushima Prefecture

The town where the hotel is located is also home to one of the world's largest hydrogen production bases.

The Japan Times

Blue Origin has filed for a 51,000 Orbital Data Center Satellite plan.

Another startup called Starcloud has also filed an FCC request to operate an 88,000 satellite constellation to support its own orbiting data center ambitions.

No doubt, other countries will enter the race.

Plus there are many thousands of additional comm satellites planned for launch.

Everyone seems to be making light of light pollution, space safety and the impact on Earth's atmosphere.

https://www.pcmag.com/news/blue-origin-joins-the-race-for-orbital-data-centers-with-51k-satellite
2/n

So with the revelation that the owner of a big Fedi server is a target of a lawsuit, and that if things go badly the server may find itself seized—

I realize that that users on that instance follow users on my instance, so there are going to be semiprivate posts of mine that may fall into the hands of people—law enforcement, data brokers—who are not beholden to any Fedi Admin Code of Honour.

(I already do not post about my crimes on Fedi, if I were the kind to do crimes.)

Server seizure is just not a part of the ActivityPub threat model. What if it was? How would it change the protocol to protect data at rest, or perhaps not even keep it at rest on a server but defer to the originating server?

End-to-end encryption [user-to-user, not server-to-server] could be part of the answer, but it need not be the whole answer.

I welcome considered thoughts, so any response I see within an hour of my posting this will be ignored.

It's time to POWER DOWN and use less electricity in a Saving Session. 👊🎉

7:00-8:00pm Friday 20th March (
Today)
(Not all regions in the UK)

During the hour, you'll get 93 Octopoints for every unit of electricity you save compared to normal. This will be added to your account within 14 days.

You must opt in - check your email, or your octopus dashboard.

#octopusenergy #savingsession #savingsession
Starting to think the real risk is not AI replacing junior staff, but senior staff quitting because they just can’t take this AI bullshit any longer and just opt for early retirement.

I liked this as a sound bite

(There’s several of them in there)

https://youtu.be/rFpvCfJ2u-g

#EnergyTransition #electricity

Jean-Marc Jancovici s'exprime sur la hausse du prix du carburant

YouTube