Once upon a time, those who promoted renewable energy were laughed at.
The FT has reported that:
Now they're blown away.
And this can only get better. There's little about which I say that at present.
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According to https://www.energydashboard.co.uk/fourtyeight it reached 22.26 GW from wind at 1300 yesterday (Wednesday 11th). Plus 2.26 biomass and 2.18 solar and 1.13 Hydro. And 5.12 nuclear.
Of course it is not about one-off peaks but meeting demand consistently day by day and week by week. Demand varies between about 20GW and 45GW so that is an impressive contribution to the total, around 50% from renewables over the last month or so. Impressive but still a long way to go.
And at some point – probably quite soon – huge amounts of storage will become essential, to save excess energy that can be generated at peak times for when it is needed later.
Agreed
I think that storage is need now. “Proof of concept” for (say) hydrogen creation (through electrolysis) and storage (for use in electricity generation) at a meaningful scale would give another boost to the renewable sector.
The concern, certainly in the North Highlands, is that the large quantities of water required for the electrolysis is not being sourced sympathetically. The upshot being some burns and lochs have been put under pressure.
Once this is sorted out the production of hydrogen in this fashion looks good.
SSE at Gordonbush have some interesting information availble on the subject.
https://www.sse.com/news-and-views/2022/04/new-gordonbush-project-steps-up-sse-s-green-hydrogen-push/
The problem with using Hydrogen is that it is a terribly wasteful storage medium. Electrolysis and compression for storage all lead to great losses, even before you’re talking about the further losses which come from using the stored hydrogen to produce electricity once again.
I know there are new approaches/catalysts under development which can improve the efficiency of the hydrogen production (and that’s a good thing), but storage is still an issue. Lots of research into potential improvements over current technology, but nothing is available at present.
My guess is that pumped heat energy storage might potentially be a more efficient, not to mention much cheaper in the future, but again, this is still technology which is under development.
It might be that hydrogen storage works out to be the best option despite the large losses, but I am somewhat suspicious that the fossil fuel companies are so keen to promote it. The possibility of ‘green’ hydrogen sounds good, but ‘blue’ hydrogen (i.e. from fossil fuels with with carbon capture) seems more likely. And nobody has resolved the difficulties/costs of carbon capture as yet. I’m an advocate of nuclear power which would make hydrogen production much more economical (though processes using the waste heat and the fact it is base load), but, unless the Small Modular Reactors under development by many companies come to the fore quickly, this seems unlikely.
I’d much rather see an alternative such as PHES work out ahead of hydrogen storage. However, it’s obviously not of interest to the fossil fuel companies so is getting a fraction of the investment going into hydrogen…
In the shorter term, regardless of what is done with grid-scale storage, it would be helpful if cheaper battery chemistries allowed the production of more localised storage for homes (something like the Tesla power wall, but with more storage and cheaper). The fact that so many homes now have solar panels on their roofs, but the energy is fed back into the grid at a laughable tariff rate (about a quarter of the cost customers have to pay!), is a terrible waste. I’m encouraged that there were apparently lots of home battery announcements at CES this year, but as long as we’re reliant on Lithium-ion batteries, the cost is going to remain high – I understand that the Tesla Power Wall 2 which offers 14kWh of storage costs well in excess of £10K including installation here in the UK. Some of the new announcements of ‘home’ batteries at CES are likely a bit cheaper, but not by a great amount.
Disclaimer: I am quite well-read on these different technologies due to an intellectual interest in the science and have a scientific background, but I am not an engineer!
It will make no difference to the price British households pay for their energy. The price they pay for their electricity will still be dictated by international gas prices; and until April will still be only partially subsidised by Government, in order to provide energy producers with eye-watering windfall profits; still quite modestly taxed.
In Scotland, where the renewably produced percentage of electricty is even higher the effect is worse. The further north you move (and the closer to the places renewable energy is produced), the higher the network grid charge made to local consumers; in a price hierarchy of network grid pricing that broadly applies the highest surcharges in the North of Scotland; in order to provide the biggest network grid subsidies in London and the south East.
Here is an excerpt from SSEN Transmission, on TNUoS (Transmission Network Use of System): “TNUoS is currently paid by all users of the transmission network; commercial and residential electricity bill payers pay to use the networks to consume electricity and both transmission connected and embedded generators over 100MW capacity pay to use the transmission network to export their electricity.Generation TNUoS is calculated through various factors, mostly location. In general terms, generators located closer to areas of demand pay less, with those in more remote areas paying more to transmit power onto the system. This results in higher costs for the delivery of renewable projects in Scotland compared to other parts of GB, with particular disparity in the north of Scotland which are furthest away from the biggest areas of demand in the south of England”.
This is an active issue for OFGEM, but we are so poorly represented by the current politics, few people are sufficiently interested or informed to ‘run with it’.
Agreed
What is the basis for this differential charging? And how big is the differential?
Does it recoup transmission losses? (Given physics, you don’t get out all of the energy you put in.)
Or does it cost more to build and maintain transmission infrastructure across remote hills and mountains than in the south east? (I can see it might be – but equally, working in the crowded environment in and around London may be more difficult and more expensive too.)
Or something else?
It appears to be a principle established for many decades (BR – Before Renewables!). Originally it may be that it reflected the fact that power stations were close to centres of high population. The matter is complex, your questions are fair and reasonable (the grid power line network to the North of Scotland was considerably uprated some years ago – specifically for renewables); here I think, among regular readers, perhaps Mike Parr may wish to comment from his deeper knowledge of the systems than I possess.
It must be said that the obsurities of TNUoS have never been presented with sufficient clarity for anyone other than industry insiders; perhaps deliberately. In 2015 there was an Ofgem report that clearly made out in one graph the disaprities I mentioned. In 2021 Ofgem called for wider discussions on the issues, suggesting there was a problem not easily explained away.
Thanks
Thanks John. This appears to be the OFGEM report you mentioned. https://www.ofgem.gov.uk/sites/default/files/docs/2015/10/reg_charges_final_master_version_23_october_2015.pdf
Are you referring to the graphs on pages 20 and 23? The table on the last page gives some numbers for the effect of moving to single national charges for transmission and for distribution without regional differences. Under the current system, as things stand, North Scotland, Merseyside and the South West seem to pay a bit more and London, the East Midlands and Yorkshire pay a bit less, but it is a relatively small percentage of the whole cost (around 5%).
Andrew,
That’s it! p.25 Bar chart. I agree it looks slight; but the y-axis is calibrated in £100 steps, for data ranging £0 up to <£600; so the differences would have to be very large to produce very significant differences. In any case, the established assumptions I am still inclined to believe are out of date; they assume power is produced/generated close to the receiving population. The underlying point is not just the quantum; the periphery does not just pay more, the sout receives a discount to a norm, the periphary pays a premium; a double whammy. Happy to be disproved.
In any case, charging people in the North of Scoltand a premium for energy seems to me inequitable. You can still post a letter for a fixed price in the UK, delivered for that price anywhere in the UK, for one price. You can no longer find that attitude when you send a parcel. Now delivery to the periphery commands a premium price by most companies (or even, I understand a refusal to send – as if the Highlands was some obscure, far off foreign country). Same for energy.
This, Scots in the Highlands are being told – is our "precious Union". So you can pay more for it, and be thankful for the privilege; and be told by Rod Liddle and the relentless Union Press that you are a bunch of chippy scroungers – the one service they receive for nothing.
If I may add a couple of comments. TUoS is only a very small part of elec’ bills DUoS is around 10x bigger. The UK’s demand in south, generation in north (Scotland) problem has been traditionally approached by building more elec infra (the West and East coast HVDC interconnectors a good example). At the same time, we have very large gas high pressure pipelines running north south (mostly from Scotland East coast). These could be repurposed to carry green-H2 produced when there is “too much wind” or simply as a way of replacing a dinishing resource (nat gas) with something sustainable. TUoS (or DUos) for gas is trivial compared to elec TUos/DUos. Taking this approach would open up some areas for RES that were hitherto far to costly (from an elec network PoV to exploit).
There is also the problem of power gen’ companies sitting on unused network assets (paying NG to reserve them). The 400kV line from a sub on the A74 to Hunterston (closed) is a good example. EdF pay’s Nat Grid to stop others using it – go figure.
In the case of gas, I have it on very good authority (think ministerial level – & not UK btw) that sucking nat gas out of the North Sea costs around £2/MWh. You may wish to reflect on that given Euro prices of circa Euro75/MWh.
Sticking on gas, Shell is making a killing on LNG – buying in the USA @ Henry hub prices (circa Euro12/MWh) and selling in Europa @ Dutch TTF prices – Euro75/MWh. Doubtless Shell are almost wetting themselves with laughter – all at yours and mine expense.
Moving back to the Uk – it would seem that the future for H2 in the Uk is blue – i.e. derived from natural gas. Quite how the economics will work (blue H2 @ current prices is ++Euro100/MWh vs green from off-shore @ circa £75/MWh). Perhaps the imbecilic tories know something I don’t – ah yes as with private hospitals – they will give a bung to those nice people at ..Shell et al to make blue.
My sources for policy etc (above) are impecable & anybody can get Henry Hub and TTF gas prices.
What is clear (& not unexpected) is that UK gov has no energy policy (or even a clear understanding), BEIS is as corrupt as ever, and Shell as rapacious as ever.
Ofgem? Worse than the three monkeys.
& in case you think it is much better in Euro land – the Germanys and the Norwegians are also heading in the direction of blue H2 (they cuddled up and reached an agreement). The only question being (your starter for 10) is “what price for the nat gas” (keep in mind the Euro2/MWh I mentioned earlier). Of course, if they did sell at say Euro2/MWh to make blue H2 other suppliers would scream “foul” followed by an interesting bun fight over “exactly how much does it cost to extract natural gas plus fair margin”.
Interesting times.
Mr Parr,
Grateful thanks. Your knowledgable insight is always very welcome.
for most readers, however I suspect the argument may be a little densely packed.
SUoS: Distribution Use of System – DUoS covers the cost of installing and maintaining local electricity distribution networks; an additional charge on the bill.
TNUoS: Transmission Network Use of System – the cost of installing/maintaining the electricity transmission system in England, Wales, Scotland and offshore; an additional charge on the bill.
HVDC: High-voltage Direct Current transmission system, typically used for long distance transmission.
That is my understanding; but my gentle point is, you may have left a lot of readers behind; sorry to seem to ‘carp’ but there is so much interesting you write on the subject, that is difficult to digest quickly for non-specialists (including myself) that could so invaluably do with some user-friendly unpacking for the illumination and attention-grabbing of a general readership.
Mike,
With all due regard to your knowledge of the specifics, everything that you’ve said about green hydrogen is all very present tense. It reminds me of the way that experts spoke when renewables-with-storage were more expensive than fossil fuels. Unexpectedly (for some) we now find that they are less expensive.
In due course green hydrogen will be less expensive than blue when the scale and technology is more optimal. Long-term, as a means of power storage, Green has an inevitable advantage in that its creation involves no fuel costs.
The Green Hydrogen future is not a matter of if but when. The current talk is of “when” being around 2030 but then again most the big advances in renewables have thus far have arrived sooner than expected.
https://www.irena.org/-/media/Files/IRENA/Agency/Publication/2020/Dec/IRENA_Green_hydrogen_cost_2020.pdf
Australia’s new Labor govt. seems to have no doubt about the prospects of H2 and their commitment to it:
https://www.allens.com.au/insights-news/insights/2021/07/hydrogen-technologies-timeline-in-australia/
Maybe it needs a combination of over-provision of wind and solar as generating costs come down, (so even when there is little wind or sun – generation still happens), grid connections to swap between high wind /high solar locations , physical storage (eg warm buildings, warm water,pumped storage.) . Doesn’t necessarily need lots of expensive and environmentally destructive batteries, expensive hydrogen or non-feasible carbon capture.
apprently the UK is nowhere near on track to achieve is 2030 and 2035 targets
https://www.bbc.co.uk/news/58160547
https://www.nature.com/articles/d41586-021-00662-3
Neither main party seems fully engaged
LCOEs for wind are going up due to interest rate increases (impacting on WACCs) and material cost increases. PV remains on a downward track for LCOEs due to efficiency improvements. All business cases for RES are based on selling ALL the elec generated. The price for elec from off-shore wind is defined by the CfD. PV if integrated with buildings/factories has its own, standalone business case. The evolution of RES costs are thus something of a mixed bag.
Wind & PV are stochastic in nature feeding power into a system that has a statistical load (one can accurately forecast load some days ahead – Nat Grid does it all the time) but which requires determinism (either generation or load) to function. These are not assertions – they are realities. Your claim that (green) hydrogen is inefficient needs to be qualified with numbers. A MW-class PEM electrolyser has an efficiency of around 73%, the 27% “lost” is mostly waste heat – which can be recovered and re-used (raising overall efficiences to 95%). There are a myriad of uses for such “waste heat” with no lack of companies willing to pay.
Because RES is stochastic, feeding into a statistical load, as the proportion of RES absorbed by the load rises, there is a non-linear increase in the amount of non-absorbed RES electricity. At 40% absorbed, the surplus is around 8%, at 80% absorbed, there is a 40% surplus (i.e. RES systems need to generate 120% of load to reach 80% absorbed). These numbers apply as much to an area e.g. St Clears in south wales as thy do to Germany (I have modelled both as it happens). Interconnectors with other countries only get you so far down the track – given these countries are also building out more RES – they will face the same sort of problems – thus we enter a pass-the-electricity parcel situation. The answer is TWh-class storage for green H2. The UK does not lack salt caverns to accomplish this. It does lack government institutions sufficienctly uncorrupted to propose any of this to politicians. In turn, the problem then becomes politicians & their advisers who have the capacity to understand any of this. The tories are too stupid, Liebore? Silence.
Thanks
The low efficieny of 75% in producing H2 is only part of the problem. You must include compressing the H2 and the inefficiency in turning H2 into electricity.
The most efficient method of smoothing out renewable power is to spread out the generators over a larger area, the wind always blows and even the sun always shines somewhere. What is needed is a comprehensive system of interconnecting DC cables.
Thanks for your knowledgeable input, Mike, as always.
What is the current end-to-end efficiency of using electricity to electrolyze water to hydrogen, compressing and storage, and reversing the process to generate electricity again?
For comparison, I understand most pumped storage (which is probably the best at-scale technology we have currently) is around 75% – that is, you get back later about 75% of what you put in. These are massive infrastructure projects that are expensive to build but can remain in use for a very long time. Will the technological kit involved in H2 storage require more regular maintenance than hydro? Dams can fail, but they don’t explode. (Cf Buncefield)
Good news, and more capacity is coming onstream quite rapidly.
However it underlines the need for new technologies to allow efficient storage and/or generation not subject to weather and time of day. In other news today it is reported that the coal-fired power station at Ratcliffe-on-Soar is having its life extended because capacity is needed to maintain output regardless of wind levels (and when it is phased out it will only be because there is reliable capacity from gas, another fossil fuel if not quite so CO2 intensive).
About a mile from me they are constructing the mainland base of a huge new offshore wind farm. It will be capable of up to 2.5GW generation – but the associated battery storage facility will only cope with about 5 minutes of that.
There needs to be huge seeding investment in prototypes to test and develop the necessary new technologies. Batteries don’t seem to be up to the scale required unless there is a major advance. It isn’t clear that H2 generation is sufficiently efficient currently for either energy storage or substitution for piped gas, but there probably need to be projects at scale for it to be developed to possible practicable efficiency. Other sources such as tidal remain largely experimental and need the challenge of actual installation (as does the proposed small modular nuclear) for its feasibility to become known.
The enormous advance in practical application of wind and solar over the last 20 years has been impressive, it needs that early incentivisation to get other necessary technologies practicable over the next 20 years if use of fossil fuels for energy generation is to end.
” It isn’t clear that H2 generation is sufficiently efficient currently for either energy storage or substitution for piped gas, ”
Please see my response to Andrew Broadbent. You are mistaken with respect to H2 efficiency.
The case for public ownership is stronger than ever.
Energy bills: People running out of energy credit every 10 seconds
https://www.bbc.co.uk/news/business-64235997
The private energy companies are just an energy mafia if you ask me. I don’t want them running our green energy future.
Proof if ever it were needed that the market is set up to enable exploitation and nothing else.
We are of course decades away from being dependent on coal, oil or gas let alone nuclear. It was only a few weeks ago when benign weather meant wind contributed virtually nothing for a 5 day period and the coal fires were cranked up at sky high prices.. the problem is storage. Lots of battery facilities are being built in the U.K. but there storage in any scale is hours when we need it to be weeks. The science isn’t there and realistically won’t be for many many years.
Second order questions are.
1) the mining of lithium
2) consequences of wind literally being sucked out of the atmosphere. After all we are interfering with nature. The papers i have read on this are alarming.
You sound exactly like those who not long ago said all renewables were bunk
Now we can print solar panels
And wind works
Srry – but you are backing the wrong horse
The replacement of lithium with sodium (for batts) is well advanced. You may care to reflect on how much sodium is available.
It is a matter of record that some Americans were opposed to Solar/PV because thet thought it would reduce the amount of sunshine available.
In response to “Ben”. PEM electrolysers produced H2 compressed to around 70bar – not far off the operating pressure of HP gas mains (circa 90bar). Which is one reason that PEMs are likely to do better than Alkaline electrolysers.
In terms of “spread renewables over large areas” – wind power output tends to correlate up to 600km. If you glance at this map & enable wind – you will see the veracity of this comment.
https://app.electricitymaps.com/map
An analysis of data in different countries confirms the visuals. It is easy to confuse “efficient” with “effective” (one can of course have both). As already noted, DC interconnectors – fine – but you will then be in a “pass-the-electric-parcel” game – given RES correlation. Happens all the time in Benelux/Denmark/Germany.France. The solution is to embed electrolysers in the system – you need that anyway so that the power system has some determinism.
Last comment: I’m not presenting “my views” on this. The posts I have made & the knowledge they contain are the result of more than 6 years of collaborative (note that word) work with other engineers, economists and some legal eagles.
We also need to think more about adapting usage to availability, rather than trying to force-fit renewables into the centralised fossil/thermal generation paradigm. Not a panacea, not even easy, but there’s a percentage to be gained there if the plant being run can have the necessary flexibility designed in. A heat pump, for instance, that could run efficiently at varying power levels according to immediate availability would leverage the inherent free energy storage capacity of the building mass. There are other tactics for improving load matching. We have an office with a small PV installation orientated, of necessity, half east and half west, but it turns out that the logs consistently show excellent matching of generation to on site load. Doesn’t solve dark days of course, but it does mean that what is produced is used very efficiently and with minimum loading of and loss within the broader transmission network.
CH4 has also been setting new UK records in the last year as a number of 50MW gas stations have come online and none are being decommissioned. It’s so useful, with a much lower CO2 intensity than coal and it’s despatchable. When people come home at night and plug in their EVs to recharge they aren’t checking that wind is delivering say 7GW or more so there’s some flexibility in the system, it’s CH4 that has to step up.
The good news is that the media seem to be fully on board with net zero (but not simple carbon reductions alas). Record prices for gas make headlines, record usefulness doesn’t. With wind, record generation makes the headlines, and high infra costs (e.g. outer Scotland as the excellent John mentioned) doesn’t.
How does that help the goal of net zero?
Net zero is the government’s goal. Ask them – they seem to invite you to committees.
It’s not my goal – I’m too much of a realist. Just take the reductions where you can get them, and that would include shale gas compared to imported, and permitting wind and pumped storage in National Parks and AONBs, which are currently verboten developments. The banning of which the Green New Deal Group implicitly approves i believe.
I thought you were troll
I care about my children’s future
You clearly don’t
The UK desperately needs more pumped-storage hydroelectric capacity. It’s the only current technology that can scale up to the massive capacities required.
One example would be SSE’s Coire Glas project – fully consented by the Scottish Government and practically shovel-ready, but stymied by total lack of interest from the British Government. That one project would provide 30GWh of storage with 1.5GW of generating capacity – equivalent to an entire power station running at full bore for 20 hours at a time.
Links?
The Coire Glas project (SSE Reneables) is a pumped storage hydro-eletric scheme based on a circular transfer of water between two reservoirs (an upper and lower); between Loch Lochy – the lower reservoir – and a new reservoir created at Loch a’ Choire Ghlais – the upper reservoir. The scheme uses energy to transfer water from lower to upper during low demand periods, and upper to lower during high demand periods.
The scheme outline is here: https://www.coireglas.com/project
There is a similar scheme near Blaenau Ffestiniog in Wales – it works
Have a look at the Drax website for the doubling of the Ben Cruachan pumped storage site.
Thanks to John for posting the Coire Glas link – I was away from my computer at the time until today.
SSE have managed to move the project along a bit since the last time I looked:
https://www.coireglas.com/news-project-news
This seems to be the latest on the policy front – the UK Government might be showing some interest in large scale storage now, although they haven’t actually committed any money that I know of:
https://www.coireglas.com/news-project-news/sse-renewables-renews-call-for-policy-action-on-long-duration-energy-storage
https://www.coireglas.com/news-project-news/government-response-to-large-scale-and-long-duration-electricty-storage-is-welcome
On a related note, here’s a press release for Drax’s Ben Cruachan doubling that Dave mentioned – quite a few interesting tidbits in there:
https://www.drax.com/press_release/drax-submits-application-to-expand-iconic-hollow-mountain-power-station/
This project is much smaller – its main purpose is to smooth out demand peaks and troughs in the course of a single day – but it’s still useful and needed. Like Coire Glas, it’s conditional on the UK Government doing their bit.
The assertion that PHS (pumped hydro storage) is the only currently scalable tech is not true. Electrolyser projects of 100MW (and more) are on-going. With a capacity factor of 40%, this means that over one year they can store (as H2) around 360GWh of energy. ITM’s factory in Sheffiled has a production capacity per year of more than 1GW (NEL Norway – 500MW). PHS takes time to build. A 100MW electrolyser system can be installed in months. The Uk’s gas network has a storage capacity of around 120TWh (the German gas network – around 220TWh) divide by 3 for only H2. This is before one even considers salt caverns – which don’t have the environmental impact of PHS. None of this is to say “don’t do PHS” – but if you are looking to store e.g. 50TWh of energy to cover multi-day periods when there is not much renewables available, then H2 from electrolysers is pretty much the only scalable tech around that can
Taking one example: Germany, when the country meets its 360GW of renewables ambition (theoretically 2030 – probably afterwards), and taking into account a growth of 25% in elec demand, then on a regular basis (2 – 3 times per week in spring and autumn) the country will face an electricity surplus of around 1.4TWhs over a 24hrs period. EV batteries cannot even hold 1/10th of that – even if there are 20 million EVs. Exporting to other countries? so that would be 80GW of interconnectors (now circa 10GW).
We are talking about system change/system redesign/system total rebuild. PHS, EVs even heat pumps fall into the class of deck chair rearraging/business as usual plus a little bit. None of them scale, from a storage point of view. For those that say I’m wrong – visit the ENTSO-E transparency paltform (https://transparency.entsoe.eu/dashboard/show) – the data is all free (& in excell form) do your own modelling. I promise you these are the sort of results (1.4TWh per day) that you will see. In the case of the UK, it is still some way behind Germany in terms of renewables. But when it catches up – it will face identical storage/scalable storage to TWh problems. (UK data no longer available from ENTSO-E – hmm – can’t think why).
Thank you, Mike – you’ve given me substantial food for thought. I’m still not buying the idea of hydrogen for vehicles or domestic heating, but I see where you’re coming from for long-duration renewable energy storage and that definitely looks workable.
As electric vehicles become the norm, and as the ability to feed electricity from their batteries into the grid becomes commonplace, and if air source heat pumps become the norm, the battery capacity in cars will be one way of levelling out peaks and troughs in supply and demand.
My recently installed air source heat pump and removal of gas heating has so far reduced the total KwH of energy the household by 56%.
Allowing energy suppliers to manage either a home battery or millions of car batteries is part of the future. Tesla (and I am no fan of the company) already offers a package deal with Octopus that manages solar panel output and Tesla battery storage at a reduced rate per KwH.
I am a fan of the idea of localised battery storage, if not of multinationals managing the system.
I am less worried about the technical ability to store energy than the lack of real policy to move to green energy, backed by government commitment and money. The solutions to energy usage reduction require up front capital, beyond the reach of most households and we have a government obsessed by short-term deficit management.
A lot of this discussion seems to be about electricity. However energy usage in the UK is about 4 times as large as electricity usage. Realistically, how can you bridge the gap with solar – available for about 8 hours in winter if there are no clouds – or wind, which sometimes doesn’t blow for weeks on end?
Can others deal with this?
That question requires a long answer from someone who knows more than I do to do it full justice, but here are some thoughts.
There are three issues here: one, how do we convert our non-electrical energy use to electricity; two, where will the electricity come from; and three, if we can’t convert something to electricity, how do we make it greener in some other way?
One: a lot of our non-electrical energy use can be converted to electricity. For example, using electric vehicles instead of petrol / diesel ones, or heating our buildings with electric heat pumps instead of gas.
Two: to get more electricity and cope with the variability of most renewable energy sources, we need to build extra capacity, diversify our energy sources and store some of that energy for times when those sources aren’t delivering as much as we need.
Diversifying our renewable energy sources is a combination of spreading out the sites and using as many different sources as we can.
For example, if there isn’t much wind in the north of Scotland, there might still be wind in Wales and Cornwall. Similarly for solar energy. Interconnectors to the rest of Europe help with that as well – you can trade energy back and forth as the weather changes.
Calm weather is often clear and windy weather is often cloudy, so solar and wind can complement each other. Adding other sources like tidal energy to the mix helps even more – tidal energy is variable too, but it’s utterly predictable, unlike solar and wind, which makes a big difference when you’re trying to run an electricity grid. Tidal energy and dedicated storage can even be combined to get constant, baseload power.
We need to build a lot more energy storage, but there’s been plenty of discussion on that already, so I won’t duplicate it here.
We may also have to accept some baseload nuclear power as part of the mix, depending on the renewable energy sources and energy storage systems we choose and how much we’re willing to spend on them.
Three: there are energy uses that can’t be converted to use electricity, or which wouldn’t be economic to convert, but we can still try to make them greener.
For example, smelting iron ore currently uses a lot of coal as part of the chemical reaction and emits an enormous amount of carbon dioxide, but fortunately the coal can be replaced with hydrogen to only emit water vapour.
If the carbon emissions absolutely can’t be avoided, the last resort is to use carbon capture and storage (more expensive and uses more energy to run the capture and storage system) or to offset the emissions by doing something like planting trees (but there are only so many trees you can plant).
Getting right down to zero carbon emission is admittedly hard, but we can certainly do much, much better than we do now.
On a related note, reducing our energy needs by making our energy use more efficient would help as well. For example, by using better insulation in our buildings, capturing waste heat from energy-intensive industrial processes or working from home (where possible) instead of commuting.