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Sometimes I hate the quality of science reporting due to obvious mistakes. > The Hydrostor facility can keep up to 10 megawatts of power, enough to keep the li
by kevin_b_er 6y ago
Sometimes I hate the quality of science reporting due to obvious mistakes.
> The Hydrostor facility can keep up to 10 megawatts of power, enough to keep the lights on in about 2,000 homes, or approximately half the town of Goderich for about five hours.
Megawatts instantaneous power, but the sentence wording makes it sound like capacity. That's how much energy it can supply at any moment vs how big the battery is.
And they talk about X number of homes for Y hours. Did they mean 10 megawatt-hours? Or did they mean 10 megawatts for 4 hours? That's 40 megawatt-hours or MWh.
Judging from this other site, it is 1.75 MW max and a capacity of 10 MWh. Which means someone messed up units in the article. Possibly even they read "MWh" from a technical summary and just guessed it meant megawatts. Because they spelled it out in the article.
http://www.energystoragejournal.com/hydrostor-and-nrstor-announce-worlds-first-commercial-advanced-caes-facility/ http://www.energystoragejournal.com/hydrostor-and-nrstor-ann...
- lultimouomo 6y agoI would have parsed the article as saying that the facility could provide 10MW power for about five hours, so with a total capacity of 50MWh... this is terrible reporting. Hydrostor own website confirms your figures: https://www.hydrostor.ca/goderich-a-caes-facility/ https://www.hydrostor.ca/goderich-a-caes-facility/
- knolax 6y agoIt's such a common error, someone should travel the country giving lectures to every journalism school about the diffences between W and Wh.
- ntsplnkv2 6y agoIt's such a common error that perhaps the terms are too close and confusing and could've used a better nomenclature.
- Reason077 6y agoIt seems to be very common to not understand, or misunderstand, the difference between power (watts) and energy (watt-hours). Even amongst technically-minded people who should know better. A respected UK newspaper once printed a dramatic article claiming "20 new nuclear power plants" would be needed to power electric vehicles in the UK. This was nonsense and all based on confusing the estimated energy use of an EV fleet (in GWh) for instantaneous power (in GW). They did publish a tiny sheepish apology several days later[1], and changed the online version of the article, but the damage was done and the claim still gets repeated today. [1] https://twitter.com/dpeilow/status/831717762259099648 https://twitter.com/dpeilow/status/831717762259099648
- eru 6y agoI don't even know why we need Watt-hours? Joule work just fine, don't they?
- Reason077 6y agoThey're measuring the same thing. Except a joule is one watt-second, which is an inconveniently small unit when talking about large energy storage like an EV battery. It would be like road signs measuring distances between cities in inches. Besides, energy has long been accounted for in hour-based units. Your power bill, for example. It's just easier to use those same units when thinking about storage, rather than rebasing everything around seconds.
- eru 6y agoI know that they are both measuring energy. It's just that Watt is usually defined as Joule / second, so Joule seems more fundamental. > They're measuring the same thing. Except a joule is one watt-second, which is an inconveniently small unit when talking about large energy storage like an EV battery. That's what we have SI-prefixes for. A Watt-Hour is also pretty small. We usually use Megawatt-hours or so. Using Giga-Joule instead wouldn't be too much of a difference. > Besides, energy has long been accounted for in hour-based units. Your power bill, for example. It's just easier to use those same units when thinking about storage, rather than rebasing everything around seconds. Yes, tradition seems to be the real reason.
- tuatoru 6y agoLet this be a lesson: assume that journalists muddle everything else as badly as this. Treat the news as an indicator that "something happened"... maybe.