It means the property can theoretically scale to 1 Gigawatt.
This is also how data centers announce new data centers. They say "We're opening a 10 megawatt data center in A-wonderful-city" this means the data center has 10 megawatts of power available, it does not mean it uses 10 megawatts or even plans to.
Over the last few years however this common scheme of headline creation has been stretched out to just an outline of theoretical expansion possibility instead of what is actually available. Eg If the new tenant has a even handshake deal with a power supplier where the supplier said "yeah we can probably get you another 50 megawatts in 1 year", they'll add this to the size of the data center/mine, which is obviously just sketchy marketing. But what else would you expect?
Even when a mine or a data center does specify how many units in servers or miners, they say "Could support 100000 servers", it does not mean they intend to install 100000 servers"
The Bitmain facility in Texas is the same marketing scheme. It is a former aluminum plant. The aluminum plant was stated to have 25 megawatts of available power. This doesn't mean Bitmain will install 25 megawatts of miners.
Another missing detail here is that there's a big difference between "continuous load vs non-continuous" load switch gear. Any sane person would say below 70% of rated capacity of non-continuous load transformers, fuses, breakers. If it is continuous load it will actually have the print "Continuous" on the switch gear and it is not that common.., otherwise not stated then it is non-continuous capacity.
By this logic you can also just take the available power of the entire state of Texas and just say that's what you could scale to, because in theory, it's true. Some companies actually do this at the city or metropolitan level, take the theoretical power output of the entire geographic area where your office is and say that's how "big" your data center is.
Anyway, they should tell the public how many miners they're going to buy and from whom. Buying them from bitmain is only going to hurt decentralization. More hash power isn't always a good thing, more distributed hash power and sourced from someone other then bitmain, is a great thing.
It doesn't exactly say in the article but I suspect wind power could be a big part of it, since that energy sector is growing a lot in Texas, and the firm running it already mines with renewables in Norway.
> Whinstone US agreed to be acquired by Germany’s Northern Bitcoin, which runs a bitcoin mine in Norway on renewable resources.
It must make sense economically to use wind power there for mining, given the [other big wind/mining project with investor Peter Theil](https://www.coindesk.com/peter-thiel-backs-200-million-valuation-for-renewable-bitcoin-mining-in-the-us).
You can't exactly turn wind off, so it makes sense to use that underutilized energy for mining, when it would otherwise go wasted.
[Texas is mostly fossil fuel](https://assets.greentechmedia.com/assets/content/cache/made/assets/content/cache/remote/https_dqbasmyouzti2.cloudfront.net/content/images/articles/ERCOT_energy_decade_1766_985_80.jpg)