Greening Our Energy: How Soon?

This article includes a video and almost verbatim text of a 40+ minute public talk at Sawyer Hall, Nailsworth, on Thursday 22nd February given by Dr Richard Erskine, Education Lead for Nailsworth Climate Action Network. The numbered paragraphs refer to the slides, but only some of the illustrations from the slides are included in the text below. It’s better to play the video to see the slides alongside hearing the words. At the end of this piece are Acknowledgement, References, and some Questions and Answers from the event.

Update 13 March 2024: Report from the House of Lords on Long-duration Energy Storage: Get On With It underlines importance of storage to get us to fully clean energy system, dominated by renewables, as the talk sets out.

Update 16 April 2023: A great new blog Is a 100% Renewable Energy Grid Possible? by scientist Michael de Podesta also comes to the conclusion that 100% renewables can be achieved.

A recorded online version of the talk can be found here:

1 Greening Our Energy: How Soon

Thank you for coming in this presentation. I really want to help you to understand the potential for solar and wind to get us off oil and gas and fossil fuels in general. You’ll no doubt know – if you’ve looked in the paper or on social media – that there’s lots of opinions flying around about what’s possible and you often see numbers being thrown around. I think it’s very easy to feel bamboozled by some of the big numbers that are thrown around and statements made. 

Can you put your hands up if you feel a little bit bamboozled sometimes by what you read? I’ll put my hand up as well. 

2 Net Zero by 2050?

Well that’s understandable but the interesting thing is that when we look at a recent survey [1], eight out of 10 Britains were concerned about climate change, and over half of them (52%) thought that the net zero target for 2050 should be brought forward.

3 Questions we aim to address

I want to try to address three questions in this talk:

• Firstly, could all of future energy demand be met by wind and solar? now that’s not to discount other forms of low carbon energy, but if we can show that it can be done with wind and solar, then of course, any other forms of low carbon or zero carbon energy that are available will simply make that goal easier to meet it won’t make it harder to meet.
  • Specifically, nuclear has met about 20% of our generation needs over recent decades, and it is likely with new projects to continue to do so, and given the climate crisis it would be foolish to stop this, but I want to focus here on wind and solar. 
• Secondly, what are the opportunities and hurdles on this journey, and 
• Thirdly, how soon can we do it?

4 My Journey

We are all on a journey.

My journey on these questions started with David Mackay’s famous book ‘Sustainability Energy without the hot air’ [2] which was very influential. It was forensic in working out the carbon intensity of everything we own or do, and in looking at the possible ways to get off fossil fuels.

I later attended the course Zero Carbon Britain (ZCB) at the Centre for Alternative Technology (CAT) [3]in Machynlleth, and this inspired me to believe that we could actually do it. 

5 New look at Mackay’s UK numbers

The David Mackay analysis was brilliant but it suggested that we would struggle to get to 100% renewables because the one thing Brits are all good at is saying: “NO!”. No to this solar farm; no to those new pylons; and so on. He was accused of being pro nuclear because he felt we unavoidably would need plenty of it. He replied that he was only in favour of maths.

However, solar and wind costs have fallen dramatically. British opinion is now firmly in favour of renewables. This recent paper [4] – I’ll refer to it as the ‘Oxford paper’ – has revisited Mackay’s numbers and I will share their findings.

6 … and not forgetting a global view 

And let’s not forget the paper [5] that made a big splash because it showed that increasing innovation could result in trillions of cost savings if the world pushed hard for renewables.

7 An over abundance

People talk about fusion power which is famously always 50 years away.  But we have a fantastic fusion reactor up in the sky – it’s called the Sun! The Sun deposits 170,000 Terawatts of energy on the Earth, which is about 10,000 times more than humanity needs currently. And – wait for it – Shell pointed this out in 2005!  [6]

Is anyone really saying that humanity doesn’t have the ingenuity to harvest just one 10,000th of the energy we get from the Sun? Are they really saying that we cannot use this massive over abundance of energy from the Sun?

8 How is UK doing so far?

Before looking into the near future, let’s do a check on where we are. We keep being told we have been leaders. So are we?

Yes and no.

We were certainly leaders when we passed the Climate Change Act in 2008, and when the 2050 Net Zero target was incorporated in 2019. Now look at the numbers.

9 Fossil fuel (FF) UK in 2017

The picture below from the Centre for Alternative Technology (CAT) Zero Carbon Britain (ZCB) report [3] shows that primary energy in 2017 was 80% fossil fuel [I chose CAT’s graphics in part beause they are better for clear and uncluttered communication of the information than many other source – in the talk I overlay some of their slides with key messages in text boxes].

Primary energy is the inherent energy in a lump of coal for example. But when you burn fossil fuels you lose energy in heat that doesn’t do useful work and so you lose 25% of that. 

The other key point is that only 20% of delivered energy was electrified at in 2017.

10 Decline of coal in electricity

This Our World In Data graphic shows what has happened in the last 40 years. Coal in electricity generation has dropped from 60% to almost zero [7] in that period. This was a great achievement.

11 The dash for gas

But again, just looking at the electricity generation, gas generation has displaced coal [8]. A cleaner form of energy but still a fossil fuel putting carbon dioxide in the atmosphere. [8]

12 Renewables growing fast

But renewables in recent years, due to their plummeting costs, have been growing really fast over recent decades, and it’s nearing 40% of annual electricity generation. Half of this comes from wind. [9]

13 Good news, bad news 1/2

Good news, Bad news.

Whether it’s the climate change committee or the national audit office or lawyers: they’re telling the government to pull your finger out if we’re gonna to get to clean the clean grid by the middle of the next decade. 

Climate Change Committee’s 2022 Progress Report showed that only 8 of 50 key indicators were on track. A pretty dismal performance by the Government.

As Victoria Seabrook of Sky News reported [10], The National Audit Office has also been damning:

“The longer it takes before government finalises its delivery plan, the greater the risk that it won’t achieve that ambition to decarbonize power by 2035, or that doing so will cost consumers more”  Simon Bittlestone, National Audit Office, Director of value for money studies.

Energy bills may rise again without government plan to deliver 2035 clean power target, NAO warns – A missing plan to decarbonise Britain’s electricity network is costing households, the report warned. The NAO audit prompted calls for government to lift a de facto ban on onshore wind.

Government lawyers are warning of a risk of litigation against the Government for its laggardly performance.

14 Good news, bad news 2/2

The good news is we’ve been cleaning up the electricity that is currently in use, but we’ve been slow to electrify the large chunks of the economy that are currently not electrified. Transport and heating are the two big ones.

15 Demystifying energy

I want to spend some time demystifying energy a bit.

16 What is energy?

The great American physicist Richard Feynman said that “Energy is a very subtle concept. It is very, very difficult to get right.” [11]

There’s energy in a food bar, in a battery, and in some petrol. They seem totally different – like chalk and cheese!

For our purposes, we can say energy is any source of usable power. It comes in different forms, chemical, solar, nuclear, electrical, etc.

It can be transformed from one form to another, usually with some loss of energy in the process. 

This is quite important.

17 Power vs Energy

I want to use an analogy of pouring water. This 40 watt lightbulb uses a hundred times less power to drive it than the kettle. So think of the rate of water flow from here to here as equivalent to the power that’s being used. The energy consumed is then analogous to the total amount of water poured over a certain period of time. If you go for 24 hours we will get a kilowatt hour of an hour of energy used by a 40 W lightbulb. The 3 kW kettle draws much more power – which is analogous to pouring the water much faster like this – so will get to 1 kWh of energy used much sooner (in just 20 minutes).

18 Power & Energy on UK scale

If we scale power and energy up to our UK population of 60 million or so, everything is multiplied by tens of million. 

So it’s typical for the UK currently to draw on 40 million kW of power, which we call 40 gigawatts (40 GW) for short.  Over a year – which is 24 x 365 hours – this amounts to 350,000 gigawatt hours, which we can call 350 terawatt hours (350) TWh for short.

Country sized power tends to be in tens of GW, whereas country sized energy per year is in hundreds of TWh.

So does that mean we simply install 40 GW of wind, or a bit more to deal with less windy days or days with more demand? Not quite!

19 ‘Capacity factors’

The nameplate power rating of a wind turbine does not reflect the fact it is not always windy. The capacity factor is an adjustment that takes account of this. 

For wind in the UK, the capacity factor is 40%. 

For solar, given our highish latitude, the capacity factor is 10%.

So 1 GW of offshore wind delivers 3.5 TWh of energy per year.

Whereas 1 GW of solar delivers 0.9 TWh of energy per year

So why not ignore solar for the UK?

Because in winter, wind is high and solar is low, whereas in summer, wind is low and solar is high. 

Most of the time, they compensate for each other in a very effective way.

20 Demystifying efficiency

Efficiency is a really key topic when we look at how we use energy. If there are two ways of getting the same result but one uses twice as much energy, it means you’ll need twice as many resources to achieve the result. 

21 What is energy efficiency?

The result we want with a lightbulb is to light up a small room. Suppose we need 400 Lumens of light to do that. Then a 40W Incandescent light bulb would do that job. But it comes with large energy losses. Only 10% or less of the electricity put in is transformed into light. So we say it has an efficiency of 10% or less. [12]

22 Less energy loss improves efficiency

With a 6W LED lightbulb we can still get the result we want – 400 Lumens of light output – but with much less loss of energy through heat loss. So the efficiency increases to typically 60%.

23 Electrification revolution 

The electrification revolution is key to achieving greater efficiency, because in those areas of energy use where we burn fossil fuels, there is often huge inefficiencies.

24 Faraday invented ability to turn motion into electricity

There is an apocryphal story that Michael Faraday was asked by a politician “what use is electricity?” and he replied “What use a baby?”. That baby has been through its childhood and is now ready to enter adulthood.

The electrification revolution is really not new. Michael Faraday showed how to turn motion into electricity, and the reverse of this, to turn electricity into motion. This is what an electric drill does. 

Over the two centuries since Faraday and others made their discoveries various forms of energy use have been electrified. Candles were replaced by light bulbs; Mills moved from water power to electric power; Electric washing machines and other household devices replaced muscle power – arduous manual work.

But some aspects of our lives ended up being powered by burning fossil fuels, and we turn to these now.

25 Petrol/ Diesel Cars

An internal combustion engine burns petrol/ diesel to create power at the wheel, but it loses at least 70% of the primary energy in the fuel, so a petrol/diesel car only has an efficiency of 12-30% overall [13].

26 Electric Vehicle (EV) cars

An Electric Vehicle has much lower losses to create the same forward motion, losing about 20% of the energy stored in a battery. So overall, an EV has an efficiency of 77% [13]. For those EVs that include regenerative braking, they can achieve even higher efficiency.

Great Britain currently uses the equivalent of 445 TWh from petrol and diesel road vehicles. As we’ve just calculated, if this was electric we’d need just 118 TWh. Almost 4 times less [14].

27 Gas boiler for heating

A Gas Boiler is designed to create heat, but there are still heat losses that do not go towards heating rooms or water for taps. A modern condensing boiler can have an efficiency of almost 90% (although often they are setup poorly so do not achieve this level).

So for every 1 kWh of primary energy in the gas that is put in, 0.9 kWh of heat is delivered to the house.

28 Heat pump for heating

Before I talk to this slide, who has a heat pump?

OK, just a few.

Hmmm, Who has a fridge? Looks like most or all of you. But did you know that a fridge uses a heat pump. 

A heat pump is a device, invented in the 19th Century for moving heat from one place to another. For a fridge, it moves it from inside the fridge to outside of it.

For heat pumps that are used for heating, an air-source the heat pump harvests the ambient energy in the air outside the house, concentrates it, then moves it inside the house, for space heating or water heating.

Then 1 kWh of electricity is augmented by 2 kWh of thermal energy from the environment, resulting in 3 kWh of delivered heat inside the house. This is an effective efficiency – or Coefficient Of Performance (COP) – of 300% [15].

29 Heat pumps usable in any home 

And contrary to received opinion, heat pumps can heat any house that a gas boiler can heat [16]. The key ingredients are a proper house survey; appropriate sizing of the system elements; and properly training technicians installing the system.

(Note: I wrote a blog that attracted a lot of attention ‘Insulate Britain: Yes but by how much?’ that provides a repost to the idea that ‘deep retrofit’ is needed before one gets a het pump)

30 Electrification is future-proofing

As David Mackay observed, electrification is future-proofing. The end users of electricity, be they light bulbs, heat pumps, cars or industry, really don’t care where the electricity comes from.

And if new forms of energy prove to be advantageous in the future, we can simply plug them into the grid.

31 How much energy will UK use in the future?

So how much will the UK use in the future?

32 Electrification reduces demand

The CAT ZCB report estimated that in a UK that has stopped burning fossil fuels, where most energy use is electrified, the energy demand would be reduced by 60% to around 700 TWh.

They included quite ambitious goals for improved public transport, but others such as the Oxford study [4] referred to earlier have come to a similar estimate without assuming major behavioural change.

33 What about new demands in 2050? 

The Oxford Study conservatively doubled this figure (to 1400 TWh) to allow for new or novel demands such as generative AI [17], synthetic meats, direct carbon capture, etc.

The Royal Society [18] estimates we’d need 100 TWh of hydrogen storage.

So in total, a generous 1500 TWh of energy demand is the estimate for 2050. to meet the mainly electrified demand.

34 Is it feasible with wind and solar alone?

But is this feasible with wind and solar alone?

35 UK has best wind resources in Europe

The UK has the best wind resources in Europe [3], so we are very lucky in that regard.

It’s interesting to note that at the start of the Industrial Revolution, Britain had as much energy reserves in the form of coal, as Saudi Arabia was discovered to have in the form of oil in the 20th century [2].

Now, the UK could use its wind resources to power a new Green Industrial Revolution. How lucky we are if we are wise enough to grasp the opportunity.

36 Hornsea wind farm phases

The Hornsea wind farms [19] phases 1, 2 and 3 in the North Sea will deliver 129 TWh per year, and wind farms such as these can be constructed pretty quickly.  We just need to accelerate the planning processes for additional wind farms.

Floating wind resources in the deeper waters further north will benefit from even stronger wind.

37 Plenty of space to spare

Overall, having assessed the feasible use of land and sea area, the Oxford study concluded that they could even double the 1500 TWh energy supply.

With 1500 TWh, the land and sea areas required to meet the demand are modest. As a comparator, golf courses take up 0.5% of UK land.

And we won’t run out of minerals either, as a comprehensive study has demonstrated [20].

38 Infrastructure & End-use growing – in parallel

There is a perverse argument used to question the rise of EVs – not enough charging points. Or heat pumps – not enough installers. As with every transition, the growth in a new end-use is accompanied by its twin: the growth in a new infrastructure. They are like twins, running a marathon together.

39 What what about variability in wind and solar?

The question naturally arises as to the variability of wind and solar. The extreme scenario is an anti-cyclone stuck over Britain for 2 weeks with poor wind and solar power generation. 

[Note added 14-5-24: An analysis of the general requirements for storage (both in terms of energy stored and power capacity) is avaialble at Storage Lab [27] ].

40 Mismatch!

Even in less extreme, or quite normal situations, the supply might be much more than needed sometimes and less than what is needed at other times.

How would we deal with this mismatch? 

There are many ways to try to address this. Over a day’s cycle, we can shift demand using a smart grid and smart tariffs. We can get more or less electricity from our European neighbours. There is scope for large degrees of flexibility in the system, to flatten the peak demand.

41 Over-build option

But over slightly longer periods, like a week, we need to do more. One way is simply to build more than we need – this is termed ‘over build’, which obviously comes at a cost, but the cost of both solar and wind have plummeted so this is clearly an option.

42 Energy storage option

Another option is to store excess energy – when it is blowing hard – and to pay it back to the grid when there is a shortfall in supply. This also comes at a cost – to build the storage systems and means for regenerating the power. The choice between over build and storage options depends in part on their relative unit costs.

For the extreme case of a persistent anticyclone, over build alone cannot fix the problem. More turbines on a windless day won’t cut it. So storage has to be at least part of the solution.

43 High wind & solar challenge

But interestingly, studies have shown [21] that the need for massive storage only gets significantly pressing when the fraction of energy from wind and solar exceeds 80% of the total energy mix (which is what this graphic by Ken Caldeira is showing).

44 Batteries will play a role for shorter term

One of the beauties of renewables is that they can exist at multiple scales – for a homeowner, for a community, for a region and for a country. Storage too can exist at these different scales, as many homes who use batteries alongside their rooftop solar PV systems can attest to.

Large battery units are already playing a role in helping to ease pressure points on electricity grids.

45 Dinorwig hydro energy storage

At a larger capacity, the Dinorwig hydro energy plant provides good scale energy storage, able to respond very fast to peaks in demand, or losses in supply [22].

It’s a strategic asset for the UK, but again, it would not be enough to deal with a long-term energy or inter-seasonal storage needs.

46 Hydrogen long-term storage

A recent Royal Society report on long term storage has concluded that hydrogen will play a key role. The hydrogen can be created using electricity when there is an excess of wind or solar, and then stored, and can be used to generate electricity using a fuel-cell to put back on the grid when we need energy back.

In East Yorkshire alone, there are 3000 potential salt cavern locations totalling 366 TWh of stored energy [18].

(Editorial Note: I should stress that hydrogen in this context is for long term storage, NOT for heating. As the Climate Change Committee has projected, heating will be mostly met by domestic heat pumps and district heating – and the district heating itself will often be community-scale heat pumps. The reason for this is the vastly greater energy efficiency of using heat pumps as compared to burning hydrogen in our homes. But this is another talk!)

47 Modelling is key to ensure feasibility

Modelling of the whole system is key, including real-world weather and demand data to test the feasibility of potential solutions, over individual months …

48 Ensuring balance during extremes

… but we must also model system behaviour over decades. 

They looked at weather data over a 40 year period to seek out worst case lulls.

It is always very odd that newspaper articles or social media posts raise the issue of lulls as though it is a gotcha discovery. Unsurprisingly, scientists and engineers are not stupid and have of course included the issue of lulls in their projections.

49 Revisiting the questions 1/3

So let’s revisit the questions I raised. Yes, we could meet future demand using just wind and solar. There is an over-abundance of renewable energy and it is an effectively limitless resource.

And the Climate Change Committee broadly agrees, based on their recent report ‘Delivering a reliable decarbonised power system’ – although some of the details differ. And at least in the medium term, anticipate reliance on gas turbines with CCS as backup.

There are many permutations, as to the detailed plans for the transition, but the end-goal feasibility question is settled.

50 Revisiting the questions 2/3

The opportunities are legion: 

• to stop damaging the planet; 
• to have clean air in our homes and towns; 
• to stop being reliant on petro-states and volatile international energy markets; 
• and to create a new vibrant economy based on green energy.

The hurdles are also there: 

• regulations and an ossified planning regime that has slowed deployment of onshore wind, solar and grid connections. 
• We also need electricity market reforms. 
• But the biggest hurdle of all has been the lack of long-term thinking and political leadership at all levels of government.

51 Revisiting the questions 3/3

I think that ‘How soon’ is a poorly defined question:

• How soon to displace the current gas generating capacity? 
• Or how soon to electrify the 80% of demand that is not yet electrified? 

Those are two different targets.

The key ‘How Soon’ is really How soon will we have a government committed to a fully fledged plan to mobilise the economy – including the talents, skills, regulations and incentives needed – to start us on an accelerated path to net zero. 

The Oxford paper’s recommendations are:

• Remove barriers to new solar and wind energy capacity.
• Continue to incentivise accelerated solar and wind energy investment.
• Invest in storage solutions, grid upgrades and, where necessary, grid services.

52 Fast transformations not new

These photos of New York street show the change from horse drawn carriages to petrol cars in just 13 years; from 1900 to 1913.

Transitions can be very fast, if the will is there.

We just need to stop the mixed singles to the public and to industry and push on hard.

53 Final reflections – Embrace optimism

One of the lessons that’s been important for me to learn is that its possible to believe both that things are deeply worrying, but that some positive changes are in train, thanks to the work of many people. 

A sustainable future is possible if we make progressive choices, for people and planet. It’s ok to be optimistic about the future, while recognising the challenges we face. Resigning oneself to catastrophe is a recipe for inaction and despair, and I for one reject that choice. 

I’d recommend Hannah Ritchie’s recent book ‘Not the end of the World’ for anyone wanting a boost of positive thinking on the choices and opportunities we have to build a sustainable future for people and planet [23].

54 Final reflections – System change more than mere substitution

System change more than mere substitution

• 30 million EVs is not the answer to 30 million petrol and diesel cars (but how many?)
• System change not merely substitution.
• We need less clogged up, people friendly, walkable towns & cities
• Electrification of improved bus, tram & rail services also key, alongside EV cars.

55 Final reflections – We need head, hand and heart

I’d like to close by returning to Machynlleth, and the Centre of Alternative Technology, where my journey began.

While there studying energy futures we found time to spend time with nature. 

Here are two fellow students Sarah and Rosie who placed their hands on a tree for me. 

A green energy transition is essential to save the planet, and create a new thriving economy and society which enjoys abundant energy enabling education, health and agricultural benefits in impoverished communities [24].

But it’s not inevitable that head, hand and heart will work together to create a fairer world. 

We must therefore strive to put communities at the heart of everything we do, to decentralise power as far as possible, and not to perpetuate current injustices.

56 Thank you

Now please, can we have questions.

Please keep questions short as I will repeat each question to ensure everyone can hear the question and my response.

After Q&A, we can break up and move around, get a cuppa, and mingle. NailsworthCAN would very much like to share what we have been doing and to hear from you. We are keen to continue to tap into the talents and ideas of the community.

Richard Erskine, 2024

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ACKNOWLEDGEMENTS

The talk includes insights from many people: Ken Caldeira [21], Richard Hellen [25], David Mackay [2], Hannah Ritchie [23] and Rupert Way [26] to name just a few.

And from many institutions: The Centre for Alternative Technology [3], Our World In Data [7-9], Oxford Univerisity (including the Smith School of Energy and the Environment), The Royal Society [18], The Schumacher Institute and the UK’s Committee on Climate Change, to name just a few.

How these insights and some materials and data have been used here – including any errors or omissions – are the sole responsibility of Dr Richard Erskine.

The figures used from reports are overlaid in the presentation with annotations using large text to highlight the key messages. Anyone wanting to see the original figures and data are directed via links to the sources.

REFERENCES

1. IPSOS (2022), 8 in 10 Britons concerned about climate change – half think net zero target should be brought forward: half think it should be brought forward, 2nd August 2022, https://www.ipsos.com/en-uk/8-10-britons-concerned-about-climate-change-half-think-net-zero-target-should-be-brought-forward 
2. Mackay (2008), Sustainable Energy without the hot air, http://www.withouthotair.com/
3. Centre for Alternative Technology (2019), Zero Carbon Britain: Rising to the Climate Emergency, https://cat.org.uk/info-resources/zero-carbon-britain/research-reports/zero-carbon-britain-rising-to-the-climate-emergency/  (this is an update of a previous CAT report Zero Carbon Britain: Rethinking the Future)
4. Smith School of Enterprise and the Environment, Oxford University, Wind and solar power could significantly exceed Britain’s energy needs, https://www.ox.ac.uk/news/2023-09-26-wind-and-solar-power-could-significantly-exceed-britain-s-energy-needs 
5. Decarbonising the energy system by 2050 could save trillions – Oxford study, https://www.ox.ac.uk/news/2022-09-14-decarbonising-energy-system-2050-could-save-trillions-oxford-study 
6. Niele, Frank (2005), Energy: Engine of Evolution, Shell Global Solutions, 2005
   • In the text Frank Niele mentions a solar intercept of 170,000 TeraWatt (TW = 1000 GW). This is not the practical maximum for solar power we could harness (and Niele is not saying that, but some people might misread it that way). Due to a number of factors (we would only want to use a small area of land for solar, the efficiency of PVs, etc.) the practical limit is very much less. BUT, even allowing for this, the amount of energy is so massive that we are still left with an enormous potential, that far exceeds the 40 TW requirement. Humanity will need (in his 2050 projection) ’only’ about 1 million square km (or 0.67% of the Earth’s land area). So, in practical terms, there is no ‘functional limit’ in respect of the energy that humanity needs. The calculation backing this up is in Note 16 of my essay Demystifying Global Warming and Its Implications.
7. Annual generation of electricity using coal in the UK, https://ourworldindata.org/energy 
8. Annual generation of electricity using gas in the UK, https://ourworldindata.org/energy 
9. Annual generation of electricity using renewables in the UK, https://ourworldindata.org/energy 
10. Victoria Seabrook, Energy bills may rise again without government plan to deliver 2035 clean power target, NAO warns, Sky News, 1st March 2023, https://news.sky.com/story/energy-bills-may-rise-again-without-government-plan-to-deliver-2035-clean-power-target-nao-warns-12822138  
11. Feynman (1969), From an address “What is Science?”, presented at the fifteenth annual meeting of the National Science Teachers Association, in New York City (1966), published in The Physics Teacher, volume 7, issue 6 (1969), p. 313-320
12. Consumer Guide to Energy Efficient Lighting, https://www.energy.gov/sites/default/files/2021-08/ES-EE Lighting_080921.pdf 
13. EPA, All-Electric Vehicles, https://www.fueleconomy.gov/feg/evtech.shtml 
14. Hannah Ritchie, How much more electricity will the UK need to switch to electric vehicles?,15th September 2023, 7th August 2023, https://www.sustainabilitybynumbers.com/p/uk-ev-electricity-demand
15. Hannah Ritchie, The future of low-carbon heating is heat pumps, https://www.sustainabilitybynumbers.com/p/heat-pumps 
16. Energy Saving Trust, From flats to terraced houses: heat pumps are suitable for all property types, 3rd May 2022, https://energysavingtrust.org.uk/from-flats-to-terraced-houses-heat-pumps-are-suitable-for-all-property-types/ 
17. Jared Anderson et al, POWER OF AI: Wild predictions of power demand from AI put industry on edge, 16th October 2023, S&P Global Commodity Insights, https://www.spglobal.com/commodityinsights/en/market-insights/latest-news/electric-power/101623-power-of-ai-wild-predictions-of-power-demand-from-ai-put-industry-on-edge
    • “From 2023 to 2030, we are looking at about an 80% increase in US data center power demand, going from about 19 GW to about 35 GW,” Stephen Oliver, vice president of corporate marketing and investor relations at Navitas Semiconductor, said in an interview. Since total US demand is expected to rise to about 482 GW in 2027 (let’s assume 500 GW by 2030), the 35 GW for data centres is about 7% of the total – significant but hardly existentially large.

18. Royal Society, Large Scale Energy Storage, September 2023, https://royalsociety.org/-/media/policy/projects/large-scale-electricity-storage/V1_Large-scale-electricity-storage-report.pdf?la=en-GB&hash=90BC8F8BCBC2A34431B6CF9DD80A8C9D 
19. Hornsea Wind Farm, https://en.wikipedia.org/wiki/Hornsea_Wind_Farm 
20. Seaver Wang et al, Future demand for electricity generation materials under different climate mitigation scenarios, Joule, Volume 7, Issue 2, 15 February 2023, Pages 309-332. https://www.sciencedirect.com/science/article/pii/S2542435123000016?dgcid=author
21. Caldeira (2018), Geophysical Constraints on the Reliability of Solar and Wind Power in the United States, https://kencaldeira.com/2018/03/geophysical-constraints-on-the-reliability-of-solar-and-wind-power-in-the-united-states/ 
22. Dinorwig, https://en.wikipedia.org/wiki/Dinorwig_Power_Station 
23. Ritchie, Hannah, Not the End of the World – How We Can be the First Generation to Build a Sustainable Planet, Chatto & Windus, 2024
24. Abundant Energy, BBC Inside Science, Host Gaia Vince, BBC Radio 4, 9th February 2023, https://www.bbc.co.uk/programmes/m001hx4x 
25. Richard Hellen, energy analyst and Fellow of The Schumacher Institute, https://schumacherinstitute.org.uk/management-team/#member-25495-info
26. Rupert Way was co-author on both the key paper [4] above, and the 2022 paper [5] – which had considerable worldwide coverage – that showed the world could save trillions of dollars if it moved rapidy to scale up renewable technologies such as wind, solar and electrolysers
27. How much storage do we need?, Storage Lab, https://www.storage-lab.com/system-value

Questions & Answers

The answers given are broadly as given but with a little embellishment in a few cases. Some references added to help in solidifying the points made.

Will there be room for nature in this move to renewables, and recognising that the ecological crisis and climate crisis?

Yes. As I said, the ground mounted solar included in the Oxford paper would require 1% of UK land, but pasture takes up 30% and ground mounted solar can co-exist with grazing sheep for example.

There is a The Fallacy of Perfection, that requires that new solutions are perfect while ignoring the harms of the status quo. Extraction for coal alone in 2021 amounted to 7,500 tonnes, whereas “Estimates for the maximum amount of materials we’ll need annually to build low-emissions energy infrastructure top out at about 200 million metric tons, including all the cement, aluminum, steel, and even glass that needs to be produced.” – and once built, this level falls away, whereas with fossil fuels we keep on having to extract it. On land use too, renewables are better than fossil fuels if we look at the full life-cycle (extraction through to operation).

But it is also true that in UK we are not always very good at consulting on projects. We do a cursory consultation, then spend a lot of the budget, then start to raise questions on the requirements while construction is in full flight (HS2 was a case in point). Good project practice is to do a thorough consultation that truly listens to and engages with the public and articulates the impacts, costs and benefits of a new project and the status quo, then pilot and prototype to test out proposals, before then proceeding. Politicians are too often led by industrial partners wanting to push ahead without delay. We can build fast, but we do need to build the right assets in the right places for the right reasons.

Too often, there seems to be a belief that nature-based solutions are in conflict with technological ones, but the truth is we need both. For example, nature based approaches to flood alleviation (like SUDS) are needed, but in many cases, engineered ones (like the Thames Barrage) are needed as well. But on decarbonising our energy, technologies like wind, solar and electrolysers are essential, and as we have seen, they leave the great majority of available land area for nature to thrive, if we choose to use it to address the ecological crisis; it’s not renewables stopping us doing it!

With the greater degree of flexible working, particularly following COVID, and also streaming of top shows … will that help to flatten the peaks in demand?

Great thought! That sounds very plausible and I’m tempted to look into the data to see if this is indeed true. The general message is that there are lots of additional ways in which demand can be nudged to help lower peak demand. 

Isn’t it a worry that so much comes from China – batteries and the minerals used in them and elsewhere? … use lots of dirty energy … 

Yes and no. It’s those twins again. A lot of claims are made about a minerals crisis by the Seaver Wang paper from last year did a thorough study of this question, and concluded that we have more than enough minerals to decarbonise the world’s economies. However, we do need to diversify our supply of minerals, and not be over reliant on China, that is true. We have to manage political risk. As an example of diversifying sources, Lithium is now being mined in Cornwall. Canada can open up its reserves of minerals.

How large a role could community energy play in the energy transition?

That’s an important question. I made the point that renewables have the benefit of being possible at all scales. The more we can have renewables at local scales, the more resilient we are, and the less the risk of power being solely in the hands of centralised conglomerates. Some of the largest wind farms are owned by private companies that aren’t British. So I’d like to see a lot of community energy. How much of a town’s energy could be produced locally will vary a lot according to the location, and may also vary through the seasons. It’s not clear whether we’re in a position to put a number on it or decide what is optimal. However, a town will still need to be connected to the national grid because it isn’t always windy or sunny in a specific locality. Some assets like Dinorweg or future hydrogen storage facilities, are national assets, for everyone’s benefit. So we need to think of community energy as part of a whole system – giving and taking energy at different times.

[since the talk and the answer given above, I have written a piece to provide an answer to the question: https://essaysconcerning.com/2024/03/06/how-much-energy-could-a-community-generate-itself/ ]

You mentioned that there is a majority of people wanting the UK to be more ambitious, so why are some politicians thinking there are votes in delaying action?

What a great question. Hitherto there has been cross party support. In Parliament, there was almost unanimity in votes for the 2008, and the 2019 ‘net zero by 2050’ change. Unfortunately it seems it has become something that has become rather polarised – some trying to claim that there is a conflict between solving current financial issues and investing in the future. But as the 2022 Oxford paper by Rupert Way and others showed, we can actually save lots of money by accelerating the pace of transition to a green future. 

Despite claims by the Government that the UK is a leader, we saw in the talk heavy criticisms from the Climate Change Committee and the National Audit Office on the lack of progress in many areas; the UK cannot rest on the laurels of displacing coal. So currently the UK has definitely lost its position of leadership. The country can earn back a position of leadership if politicians grasp the opportunity and stop using the climate as a political football. We need to get back to there being a cross party consensus at least amongst the major parties that will last till 2050, which is 5 Parliaments away.

Could we learn from what Nigeria is doing? They have micro grids and will later bring these together.

Different countries have started from different places. The UK have had large centralised generating capacity and will now need to loosen thing up a bit to accommodate a network of resources at different scales. Nigeria is in a sense doing the opposite from what you say – having lots of local capacity before bringing it all together. I’m sure we could learn from each other.

In the last 6 months you noticed a change in attitudes toward siting of renewables? I’m finding many acquaintances have.

Yes, and we are seeing communities embracing solar and wind for their mutual benefits, as the  Channel 4 series The Great Climate Fight showed, it is often regressive Government rules and directives blocking communities from building what they want (such as a wind turbine on the edge of a village), with just a small minority vetoing progress.

Are there issues with using hydrogen, I’ve heard about?

We have to distinguish various uses of hydrogen. Michael Liebreich has a ‘hydrogen ladder’ showing where hydrogen sensibly can or should be used and where it shouldn’t. It cannot compete with electrification for cars and heating homes, and is now being relegated into relatively few areas. Energy storage is one of those. Another is fertiliser production. And there are also applications in industry. You mentioned Bath University research, so I’ll need to talk with you after to determine what issues you are referring to.

What about heat storage playing a role?

Heat storage is a great idea and there are most certainly cases for using it. I am not clear it can displace the need for long term storage with hydrogen, but I understand it could pay an important role. Its worth stressing that there is a lot of waste heat also around that could be exploited (such as from industry). Waste in our sewers could, when combined with a heat pump, supply heat, and of course there are many existing installations of water source heat pumps that can heat large building; Stroud District Council’s offices in Ebley is a case in point.

[since the talk, the following example from Princeton University has come to my attention. They will be using large heat pumps to extract heat from buildings in summer to keep them cool and store this underground, then use the heat pumps again in winter to use the buried heat to heat buildings in winter. They will create a huge thermal reservoir to achieve this outcome. https://www.princeton.edu/news/2021/11/09/going-deep-princeton-lays-foundation-net-zero-campus]

How are we going to convince people that we need a revolution in energy, especially when there are been conflict over the siting of some renewables such as the Arlingham solar array? There is a suggestion the UK should build 6-8GW of solar by 2030, but we need to take people with us.

We have to consult and engage hearts and minds? I don’t think is simply a case of not bribing people with lower bills. The use of Citizens Assemblies and other forms of engagement with the community will be key. People need to understand the benefits. A local village hall with rooftop solar, a heat pump, EV charging and a battery can become a place that brings local benefits and also helps to engage hearts and minds.

End of Q&A