Equivalent of 97% of Scotland’s 2020 electricity consumption was from renewables • Hacker News Board

Re: Equivalent of 97% of Scotland’s 2020 electricity consumption was from renewables

#141

Post by eldaisfish » Fri, Mar 26, 2021, 2:44 PM UTC

batpangolin wrote: post #95

eldaisfish wrote: post #13

Earlier quoted context omitted.

spot on. Every time this comes up, it's the same BS. The actual figure for the UK grid (there is no separate Scotland grid) is just over 40% of net electrical energy demand supplied by renewable sources. If Scotland was severed from the grid it would require fossil fuels and nuclear just like the rest of the UK. The 97% figure is arrived at by taking British renewable energy that happens to be in Scotland and subtrac…

I don't see the problem with this number. Scotland (seen as a separate energy economy) sometimes exports energy to England and Wales, sometimes imports it. Scotland's production of renewable energy, considered in total MWh, represents 97% of its consumption of all electrical energy. Clearly, in dollar value, the number is smaller since they usually export at times of low prices and import at times of higher prices. T…

Electrical energy is always in balance. Saying that 97% of Scotland's electrical energy needs were met by renewables is highly misleading because it ignores the most important piece of context - time.

Scotland could have generated 300% of daily energy demand from wind one some days. And zero on others. The reality is that one cannot be subtracted from the other to claim that net consumption is zero precisely because there is a time when that is not true.

Electrical energy is not like balance of trade i.e. it is not fungible. There is a further complication here - the assumption that there is a ready sink of generated energy. If that stops being the case, then suddenly those days of 300% demand being generated are no longer possible.

The headline is a mischaracterisation and is misleading.

Re: Equivalent of 97% of Scotland’s 2020 electricity consumption was from renewables

#142

Post by bluGill » Fri, Mar 26, 2021, 2:45 PM UTC

VBprogrammer wrote: post #64

pydry wrote: post #31

Earlier quoted context omitted.

There hasn't been nearly enough done on demand shaping. Rather than wondering how we can store all the excess capacity it's probably more cost effective to wonder how we can shift demand. Aluminum smelters in Germany use gargantuan amounts of electricity, for instance, but they can use 3x as much on Friday when power is cheap than Monday when it's not with relative ease. Using a powerwall to keep production steady wo…

The challenge with this kind of stuff is that capital costs are a big part of the cost for large industrial plants. A plant which is only using 25% of its capacity is going to be unprofitable.

When the biggest input cost is energy you are wrong. A plant that is 10% capacity by running only when energy is cheap is more profitable than a plant at 90% running at whatever energy prices are. (in the real world take my numbers and reduce by 75% - between nights, weekends, and maintenance shutdowns a real industrial plant at 25% capacity is already common)

The company I work for has two plants near each other, where one is run in winter, and one in summer, each producing a different product. The workers alternate between which plant they work at depending on the season. The other plant is shutdown for maintenance. By replacing the conveyor belt every year we ensure production never shuts down unexpectedly while people are working, and this more than makes up for the cost of a factory that is idle half of the year.

We have a lot of factories. The above two plants are not the foundry where we pour iron which I talked about in a different thread.

Re: Equivalent of 97% of Scotland’s 2020 electricity consumption was from renewables

#143

Post by avianlyric » Fri, Mar 26, 2021, 2:45 PM UTC

wcoenen wrote: post #56

pydry wrote: post #45

Earlier quoted context omitted.

>There is an increasing crisis in the UK of negative electricity prices It seems like an opportunity more than a crisis to me. There are tons of potential applications for "free" electricity. * Storage heating/cooling that's basically free * Manufacturing carbon neutral jet fuel * Cheaper aluminium production It could also lead to onshoring of certain industries which previously moved to locales with access to cheap…

It might work, but it's not necessarily going to be very profitable. The equipment that sits around waiting for low or negative electricity prices represents locked up capital, and ongoing maintenance and depreciation costs. For the same reason, it's not a good idea to have bitcoin mining equipment sitting around waiting for cheap electricity. The hardware becomes obsolete very quickly, so there's only limited time t…

With negative electricity rates you can do crazy things like buy thousands of space heaters, and just heat the outside.

Space heaters don’t become obsolete, and they’re not very capital intensive, or require much maintenance. You just need space to put them in.

Re: Equivalent of 97% of Scotland’s 2020 electricity consumption was from renewables

#144

Post by Corazoor » Fri, Mar 26, 2021, 2:45 PM UTC

sofixa wrote: post #123

Corazoor wrote: post #111

Earlier quoted context omitted.

> but the challenges of needing to store such vast amounts of energy seems like an almost impossible task Only if you don't look at all available solutions: https://en.wikipedia.org/wiki/Power-to-gas "P2G is often considered the most promising technology for seasonal renewable energy storage" I dunno why this is such an unknown technique, natural gas storage is a very old and proven technology. Yet it is ommitted fro…

If you convert Power to Gas in the form of LPG or methane you then burn for energy when renewables aren't working, you're kinda defeating one of the main purposes of renewables - low carbon output.

That is simply not true.

In order to convert elecricity to methane you first have to REMOVE CO2 from the enviroment. If you subsequently burn that gas, you arrive back at the CO2 level you had before the P2G process.

That of course only works out to net zero when you use co2 that was recently captured, like from waste-biogas or trees.

The big problem with fossil fuels is not directly that they release CO2, it is that they release CO2 that was captured over millenia in the comparatively short timespan of decades.

You can avoid that problem entirely with P2G systems.

Re: Equivalent of 97% of Scotland’s 2020 electricity consumption was from renewables

#145

Post by sandworm101 » Fri, Mar 26, 2021, 2:45 PM UTC

piokoch wrote: post #35

sandworm101 wrote: post #19

Earlier quoted context omitted.

>> Once this comes online, wind generation will often be over 100% of demand UK wide Which is exactly what I would expect from island nations. The UK has lots of coast, which means lots of wind. That is a resource to export. The cornerstone of free trade is that some things are worth more in some places and less in others. UK has lots of wind. Maybe they can trade that for imports of luxury goods from elsewhere. If o…

Yes, the point with selling electricity is that you need to guarantee that you will deliver some fixed amount of electricity. If you depend on wind power plants how this guarantee can be given? What if wind stops. Maybe it would make sense to build huge bitcoin mining data centers and mine bitcoins in case of surplus. Hardly useful, but given current coins rush could be profitable. Better than paying producers for no…

Aluminum smelters. If you have lots of cheap power you can always smelt. The raw materials are everywhere and everyone needs aluminum products. Fill the pots and spark up the electrodes as soon as power gets cheap.

https://en.wikipedia.org/wiki/Aluminium_smelting

Re: Equivalent of 97% of Scotland’s 2020 electricity consumption was from renewables

#146

Post by pydry » Fri, Mar 26, 2021, 2:48 PM UTC

SamBam wrote: post #91

pydry wrote: post #31

Earlier quoted context omitted.

There hasn't been nearly enough done on demand shaping. Rather than wondering how we can store all the excess capacity it's probably more cost effective to wonder how we can shift demand. Aluminum smelters in Germany use gargantuan amounts of electricity, for instance, but they can use 3x as much on Friday when power is cheap than Monday when it's not with relative ease. Using a powerwall to keep production steady wo…

Storage heaters, more efficient refrigerators, smart washers that turn on when electricity is cheap. I really hope these kinds of things start to increase in popularity, but I think it needs more government intervention for it to happen.

The only really critically necessary government intervention is making sure the grid can handle this.

It would probably help if they mandated smart electric storage heaters on new builds but beyond that I'm not sure you need to do much more.

You can rely on people's self interest to buy a new washing machine that saves them money, for instance.

Re: Equivalent of 97% of Scotland’s 2020 electricity consumption was from renewables

#147

Post by adwn » Fri, Mar 26, 2021, 2:49 PM UTC

bilekas wrote: post #105

adwn wrote: post #76

Earlier quoted context omitted.

> So I have no idea what you're talking about. Then you should also read the sentence directly after the one you quoted, in which it's explained: > > The equipment that sits around waiting for low or negative electricity prices represents locked up capital, and ongoing maintenance and depreciation costs.

> The equipment that sits around waiting for low or negative electricity prices represents locked up capital, and ongoing maintenance and depreciation costs But the costs over time are negligible when current alternatives will eventually only go up due to scarcity. I might be missing something.

> But the costs over time are negligible [...]

In heavy industry, they're very much not. Large machines often cost large amounts of money. You don't want large machines sitting around doing nothing when they could do useful work and earn money instead – so that you can, for example, pay off the loans you took out for them, or pay the operational staff that pulls the levers and turns the switches.

Re: Equivalent of 97% of Scotland’s 2020 electricity consumption was from renewables

#148

Post by bluefirebrand » Fri, Mar 26, 2021, 2:49 PM UTC

eldaisfish wrote: post #137

bluefirebrand wrote: post #103

Earlier quoted context omitted.

Agree, I'm missing some context to see why your parent post thought this was good enough. I suspect that "Lowest Demand" is being thought of in two different ways.

even at the lowest demand, a large, grid-connected battery can only provide minutes of back up power, and that too for only a fraction of already low demand. A storage battery is not a viable means of balancing demand and supply over a time period longer than minutes. What's needed is not more batteries but better transmission, more hydro where possible and where hydro is not possible, more nuclear.

When you're talking about lowest demand are you talking about for the whole grid? A city block? A building? A condo?

And I agree. I worked in solar and storage for a while. It's not a replacement, it's just an extension.

It works out ok for a battery system for a building but anything larger they just don't last long enough

Re: Equivalent of 97% of Scotland’s 2020 electricity consumption was from renewables

#149

Post by bluGill » Fri, Mar 26, 2021, 2:50 PM UTC

beaconstudios wrote: post #24

aclelland wrote: post #18

Earlier quoted context omitted.

Grid storage is such an interesting topic to me. We are all used to energy storage at a small scale (phone batteries, even electric cars) but the challenges of needing to store such vast amounts of energy seems like an almost impossible task, even the large Tesla battery in AU only seems to be used to help smooth the grid supply. It seems that the Scottish landscape might lend itself to more Hydro but that'll be an u…

one of the most interesting strategies for grid storage I've seen is just pumping water up a hill. Then, when you want to get the energy back, just let it flow back down through turbines. https://en.wikipedia.org/wiki/Pumped-storage_hydroelectricit... One of the potential strategies for dealing with grid storage in Europe is to turn Norway into a battery: https://www.greentechmedia.com/articles/read/experts-respond..…

Neat, but we need thousands of Hoover dam's, including the lake at the top and bottom, to store enough energy just for the US. Or to put it a different way, imagine completely draining lake Superior in just two weeks, and then over the next two weeks completely refilling it.

I'm not saying it isn't neat, but it doesn't scale to as much storage as we need.

Re: Equivalent of 97% of Scotland’s 2020 electricity consumption was from renewables

#150

Post by doikor » Fri, Mar 26, 2021, 2:50 PM UTC

Glench wrote: post #98

doikor wrote: post #94

Earlier quoted context omitted.

Yeah heat pumps are the answer to places like Scotland. As a bonus you get air conditioning. They do have some problems with extreme cold (not really an issue in Scotland or most of Europe for that matter) but even in such a case should still be used together with plain resistance heating. But that kind of cold has very few people living there anyway (think -30c or colder)

I've been wondering about this! I keep hearing that air-source heat pumps aren't great in pretty cold areas. Do you have any links or references on this? I live in the Northeast US and wanted to see what the options were and what people's experiences have been.

Basically the Coefficient of performance (COP or SCOP for seasonal version) just keeps going down with the temperature (under 1 means resistance heating is better)

https://en.wikipedia.org/wiki/Coefficient_of_performance

Models made for cold climate work to around -30c. Wikipedia has okish writeup about their functionality in cold climates

https://en.wikipedia.org/wiki/Air_source_heat_pump#In_cold_c...

Don't really have any good sources in English for this (most reading I have done on this is in Finnish)

For example here are some excerpts from a report done by VTT (the Finnish governments research center)

https://www.scanoffice.fi/vttn-testiraportit-ilmalampopumppu...

If you scroll down you can find some pics "lämpökerroin" is COP and "ulkoilman lämpötila" is outside temperature.

From that you can see that the combo of Mitsubishi Electric MSZ-LN25VGW + MUZ-LN25VGHZ still holds a COP of 2 at -30c. On the models not made for such climate/cheap ones you can see it drop to 1 (or below)