Just an innocent bystander?

The more I look into the story of the family that owned a Tesla powerwall (see previous four posts), the more I get the impression that there is more to the story than what meets the eye. In the article (and also the video that was linked to), it was the man of the family who did the talking. He was portrayed as a family man from Kermt (a tiny village with a population of 4.122) who installed a powerwall and this allowed him and his family to reduce their dependence on the power grid.

Yet, I was not really convinced. He looked indeed as an ordinary family man, but he sounded knowledgeable, the video was well made and only the advantages were highlighted, avoiding the disadvantages altogether. It seemed more like a slick sales pitch than an objective news item.

Later I learned that he signed in for the new model of the Tesla (the car). It is a hyped status symbol, not something that an ordinary family man would go for and he probably would have a higher than average salary.

There was also the puzzling tagline on his Facebook account:

Translation:

Here you find all details on the home battery of Tom Nijsen and his strive for an inter-dependent energy landscape.

His strive for an inter-dependent energy landscape?

These are not the words that I would expect from a simple family man.

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The powerwall and clear numbers: a difficult combination

A couple days ago, I read with increasing astonishing a new post on the kermtstroomt facebook account (the account of the family that owns the powerwall that was the subject of last three posts). The subject was the number of days that they didn’t need to draw power from the grid (translated from Dutch):

There are 219 days from September 1, 2016 until April 10, 2017, of which we have been able to bridge 75 days without grid because the sun produced more than we consumed! Thanks to the #Powerwall, which uses the surplus from one day on darker days afterwards, we can pull this up to 100 days. This means that we could do without grid in 100/219 = 45% of the darker half of the year!

Huuuuuuh?!?!

There is so much wrong in only three sentences.

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Easily through the night on a fully loaded powerwall

This is already the third post on the Tesla powerwall series and especially how it is (mis)presented in the mainstream media. This misinformation is not only limited to the mainstream media, it is also strong in social media. The subject of this post is a facebook post by the owners of the Tesla home battery mentioned in previous two posts.

It starts informative with a description of their powerwall (translated from Dutch):

Our home battery is a lithium ion battery with a usable capacity of 6.4 kWh (slightly less than our average daily consumption). We decided NOT to go for the #offgrid option, so when the grid voltage is lost, our battery will also not be able to power us. The battery can deliver 2 kW continuous power, with a peak power of 3.3 kW.

The capacity of their powerwall is indeed somewhat lower than their average consumption. I understood from a previous post that their annual consumption is around 3,200 kWh, meaning around 8.77 kW per day. On average of course, their consumption will be lower in summer (when production is high) and in higher in winter (when production is low).

Not sure whether all this 6.4 kWh is really usable and how long it stays that way (this battery is currently brand new, but lithium ion batteries degrade after a while). But that aside.

It becomes a bit trickier in the next sentence when it comes to the limitations of the powerwall (translated from Dutch):

With a load of 2 kW, the battery is depleted after 3 hours.

Followed by the justification that this is not much of a restriction for them (translated from Dutch, my emphasis):

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Break-even in thirty years (for something that probably will not last half that time)

The half-news show continues. The subject of previous post was the hurrah story from Belgian newspapers about a family that installed a Tesla powerwall. My impression was that things that didn’t fit the narrative were excluded, therefor coming to an overly positive success story. I wasn’t really sure whether this was caused by a wrong interpretation by the journalist or whether it originated from the interviewee.

I found out that the owner of this powerwall had a twitter account and recently started a facebook account in which he writes about his installation and (only) its advantages. Going through the posts, it seems likely that the one-sided positive narrative came from the owner and the journalist probably reported it uncritically.

Reading his tweets on the powerwall, I found a very small glimpse that it is not as positive as it was painted in the newspaper articles and the social media:

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Fully self reliant on solar power for 42 days (out of 210)

From the only-half-of-the-news-will-do department, this newspaper article titled Family from Limburg uses a home battery for one year already: “our house runs on its own power for weeks”. Not only this newspaper, all the other newspapers jumped on the story.

Screenshot article Het Nieuwsblad

Basically, a family from Kermt (a small village in the Belgian province Limburg) has solar panels on their roof and got themselves a Tesla powerwall (translated from Dutch):

For 42 days since the beginning of September, a family from Limburg has already been using the energy they generate themselves via the home battery. By storing the energy from the solar panels, it can be used when the owners see fit. “So our house runs on its own power,” says Tom Nijsen (39).

At first glance, it sounds really nice. A Tesla powerwall was installed, storing the energy produced by their solar panels and therefor making it possible to use that solar energy, even when the sun doesn’t shine. Reducing their dependence on the grid and for some periods even being self sufficient. What is not to like?

The reason why initially my attention was drawn to this article was because three statements in the title and summary were demonstrably false. You just had to read the article carefully to notice it.

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Sugar versus fat: why so many scientists got it so wrong for so long

Looking for more background when I was writing previous post, I came across a very lengthy, but nevertheless interesting story in The Guardian. This long read is titled The sugar conspiracy and the subject is the battle between the theory that sugar is the (main) reason for the obesity epidemic and the established theory that fat was the culprit.

This is not something recent, the controversy originated already in the middle of last century and, although the fats theory was found to be ultimately wrong, the sugar theory was ridiculed, discredited and careers were ruined. It took fifty years for the theory to resurface, leaving the question why the top nutrition scientists got is so wrong for so long.

We hear that objection often in climate change discussions: so many scientists can’t be wrong for so long. Well, it is possible and the sugar theory is only one of its manifestations.

The most interesting part of the Guardian story is the tension between the scientist who first proposed this theory (John Yudkin) and his scientific adversary (Ancel Keys). It reads like the current controversy on climate change. Replace Yudkin with your favorite skeptic, Keys with your favorite alarmist, fats with CO2, meat/dairy/sugar industry with Big Oil/Tobacco and the story sounds really modern. There are a lot of similarities between how the scientists in the two sciences treat those who are skeptical towards the consensus position.

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The lessons we learn from nutritional science

My employer is concerned about the health of his employees and subscribed us all to a health newsletter. Every two weeks we receive some health tips in about ten to fifteen lines, based on the latest findings in health science. In the last newsletter, there was one article that jumped out on me. It was titled “Lots of fats or lots of carbohydrates?”. This is how it starts: (translated from Dutch)

Nutritional Sciences made large blunders in the past. For a long time, we had to avoid fats to stay healthy. Not only was this the wrong advice, it also has proved counterproductive.

In the 1950s, scientists drew the wrong conclusions from population studies. They focused on fats as the only cause of obesity and heart disease. Recent studies provide a more nuanced picture: a diet rich in fats and low in carbohydrates works at least as well to lose weight!

This sounded very familiar. Until a few years ago, fats were seen as something bad for our health due to our sedentary life styles and considered to be THE cause of obesity with loads of negative side effects like hypertension and heart disease.

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