Over the past while I’ve been watching the [yoke that shows you our electricity generation in the last 24 hours.](https://www.rte.ie/eile/climate-change/)
In that time our renewable energy has moved between 2% and 70%. How is that even possible?
Like I know it’s going to fluctuate based on wind and sun and all that, but 2% and 70% is a huge variation. Am I missing something here or does renewable energy actusly change that much?
10 comments
Ya wind is variable I guess, and maybe they had to do maintenance or something ?
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Too much wind = bad for machine
Not enough wind = machine no twirl
Thank you for coming to my TedTalk.
Problem with renewables is variability. That’s why storage, in particular, pumped hydro kicks ass.
It also depends on demand. If the demand drops, wind turbines are stopped because it’s not feasible to shut down coal /gas powered generators. Whenever you see wind turbines not turning, it’s usually because there’s no demand for the power and there’s nowhere to store it.
In terms of fossil fuel plants, only gas can be turned on and off really.
So the grid will keep using the fossil fuel based plants and turn down/off renewables and gas to balance the grid.
We have sweet FA aside from wind. Scaling up solar would help keep it a bit more predictable and give us a nicer trade off in terms of summers here tend to be calm with more sun while winter has more wind but less sun. Offshore wind is a bit more predictable than onshore wind as well for a few reasons so scaling that up may help. Longer term if tidal energy starts to work out that’d be another great predictable source.
Wind and solar energy is expensive and unreliable. Windy day versus calm day. Sunny day versus cloudy day.
That is the harsh reality that no one wants to acknowledge. The world keeps building eyesore 300-foot-tall windmills that kill thousands of birds, but fail to generate a reliable stream of electricity.
The only reliable renewable energy is water turbine, typically installed at dams. So long as the water supply and flow is constant, then a constant stream of electricity results.
Used to work in the “flexible power” industry in the UK until very recently. Essentially the company I worked for owned a large fleet of small scale gas generators (think the size of a shipping container) that helped the National Grid maintain balance between supply and demand. The also owned a load of batteries that were able to do a similar job.
The name of the game in power generation on a national scale is balance. The frequency on the system is maintained by effectively balancing supply and demand and failure to maintain the balance leads to blackouts, etc.
The issue in the UK and Ireland is they have massive capacity for wind energy but wind energy is completely weather-dependant. 2021 in particular had some days-long periods of incredibly low wind which in turn saw demand for fossil fuels to increase. Battery capacity isn’t sufficient at the time being to successfully store days worth of power and it’s battery technology which really is hindering the ability to go renewable for longer periods. Battery components are also becoming very expensive at the moment due to competition from other sectors (motor industry) and scarcity of commodities.
As others have said, a breezy day with sun and lower Summer demand and there’ll be negligible need for fossil fuels bar the use of small scale gas to bridge the gap between renewable supply and demand. Batteries can be used on a smaller scale to maintain frequency on a highly reactive basis (i.e. to the second, charging when too much supply, discharging when not enough). If you get a cold February day with no wind, it’s pretty much 100% fossil fuels with the exception of small amounts of wind, solar, pump storage, etc.
Sun goes up, sun goes down you can’t explain that.