Comment on Why is coal and fossil fuels still used?
shice@lemmy.world 1 day ago
Most if not all power used is generated almost instantly as needed. So when you look at solar (which is a great renewable) you run into the fact that it only generates power while the sun is out, and a specific amount of power. This causes the problem of, how do you generate power at night and what do you do on rainy days or if a cloud covers the panels. You can substitute this with other renewable energy sources: wind, hydro, and nuclear, but wind has similar issues as solar and hydro and nuclear have huge upfront costs and take years to build. So this is where coal and natural gas come in. Coal has the downside of being really bad for the environment but can start up within 10ish minutes of being needed. Gas is better for emissions (not great), but takes more time to startup. A lot of companies use a mix of things along with buying and selling power with other companies (similar to a stock market). There are thoughts of trying to store power or looking at small scale nuclear plants.
Source: I work for a large power company
Greyghoster@aussie.zone 1 day ago
That’s where batteries and other storage systems come into play.
exasperation@lemm.ee 1 day ago
Yeah, people are working on it.
The EIA estimates that there’s about 30 GW of battery capacity in the U.S., mostly in storage systems that are designed to store about 1-4 hours worth.
That’s in comparison to 1,200 GW of generation capacity, or 400 times as much as there is storage.
It’s coming along, but the orders of magnitude difference between real-time supply and demand and our capacity for shifting some of the power just a few hours isn’t quite ready for load balancing across a whole 24 hour day, much less for days-long weather patterns or even seasonality across the year. We’re probably gonna need to see another few years of exponential growth before it starts actually making a big impact to generation activity.
shice@lemmy.world 1 day ago
Ya! And there is a lot of research and investment into them. The problem is they lose capacity over time from being powered and drained (think phone batteries and other lithium batteries). From what I know hydro batteries are actually really big with power companies. Basically pumping a bunch of water uphill when you have excess power, then using the reservoir like a hydro plant when you need power. They are really inefficient, but work surprisingly well at storing a lot of power
monkeyman512@lemmy.world 1 day ago
I’ve seen some videos talking about iron based battery tech. My understanding is that is doesn’t wear out nearly as fast as lithium based tech and less of a fire risk. Downside is that it is less energy dense, so doesn’t work for mobile applications. But that shouldn’t be a problem for stationary applications, like the power grid.
zxqwas@lemmy.world 1 day ago
They were still more expensive than fossil power on standby last time I looked.
Greyghoster@aussie.zone 1 day ago
Lots being installed around Australia and are a lot cheaper than gas power generation for covering peaks.
zxqwas@lemmy.world 1 day ago
Can you show me the numbers?
The numbers I found unsubsidized gas is about USD0.5/kWh and battery is USD150 per kWh. This is a 10 minute search so the quality of those numbers are dubious, I’m prepared to have my mind changed.