Energy
17th October 2017

Ban the Steam Engine and Build Ten Hinkleys

Article by Sanjoy Sen CEng FIChemE

Hinkley Point C artist's impression – National Grid’s Future Energy Scenarios top-end case adds 30 GW to current peak demand, equivalent to ten Hinkley Point C nuclear power stations

“IT’S a bit like saying we're banning the sale of steam engines”¹. Thus observed Aston Business School professor David Bailey in response to the UK government’s 2040 ban on “new conventional petrol and diesel cars and vans.”² Whilst initial media coverage saw this as highly momentous, the reality might prove somewhat different. As products improve and prices fall, the take-up of petrol-electric hybrids and 'pure' electric vehicles (EVs) might come much sooner. Today’s ‘conventionals’ will become obsolete long before they’re banned.

But leaping on the (low emissions) bandwagon creates new issues. Even if we all find somewhere to plug in, doing so risks chaos. National Grid’s Future Energy Scenarios³ top-end case adds 30 GW to current peak demand, equivalent to ten Hinkley Point C nuclear power stations4. (And, incidentally, baseload nuclear remains a key part of the mix, irrespective of the arguments below.)

Then, even after hours of recharging, can EV batteries provide sufficient driving range? Meanwhile, renewable energy costs (especially offshore wind) are plummeting. But a new barrier to progress is fast emerging: the challenge of balancing further intermittent (ie unreliable) grid suppliers.

Part of the solution could involve hydrogen. As we’re about to see, technical and economic hurdles still remain. But the gaps it potentially addresses and the progress seen already suggests it merits some consideration. Let’s start by understanding what it might offer.

What might hydrogen do for us?

Hydrogen (H₂) is famously the smallest and lightest molecule out there. It burns cleanly, producing water vapour only. So, what’s not to like?

Unfortunately, hydrogen doesn’t exist naturally anywhere on earth: it can’t be extracted like, say, coal from a mine. Instead, think of it as a means of storing and transporting energy, as an alternative (or even partner) to electricity and batteries. And it could prove vital in tackling the main drawback of renewables.

Windfarms often generate far more power than can be handled. But, in the absence of vast battery capacity, this can’t be stored. Meanwhile, on calm days, we still fall back on fossil fuels. This lumbers us with an unstable grid plus the costs (including government subsidies) of retaining back-up. Alternatively, (effectively free) excess renewables power could generate hydrogen by electrolysing water. This gas can then be stored more easily than electricity and be used to balance out the grid. And maybe also provide heating or power our cars.

Not everyone is a fan, though. Critics believe oil company enthusiasm stems from most hydrogen being currently generated from hydrocarbons in Steam-Methane Reformers (SMRs). And that car giants back hydrogen as it plays to their core strengths, hindering EV entrants.

But any energy transition depends on the expertise and investment of multi-nationals. And over-commitment to all-electric solutions might present similar issues to fossil fuels: the environmental impact of extracting battery metals and the political repercussions of vast reserves lying in a few hands. Let’s try and evaluate the hydrogen proposition objectively.

Excess renewables power (from windfarms for example) could generate hydrogen by electrolysing water. This gas can then be stored more easily than electricity and be used to balance out the grid.

What might hydrogen mean for the public?

As we’ve just seen, hydrogen might well play a key role in electricity generation. But at home, we tend not to notice much difference when power sources shift. Within a generation, our kettles and televisions have transitioned imperceptibly from being coal-fired to wind-powered (via gas).

More noticeable would be switching domestic heating over to hydrogen. The H21 proposal⁵ would see the city of Leeds change over entirely. Hydrogen would be generated from SMRs at the nearby Teesside petro-chemical complex with the resultant carbon dioxide stored in spent North Sea gas fields. But the complexity of ensuring the existing system (from transmission pipelines to domestic cooker burners) can safely handle pure hydrogen is not be under-estimated. Older readers will, of course, recall Britain’s transition from town gas to methane some 50 years ago: it can be done.

Instead, the biggest observable change is likely to be in cars. Early hydrogen fuel-cell vehicles (FCVs) already offer similar performance to conventionals but avoid the EV bugbears of lengthy recharging and range anxiety. Elon Musk, Tesla’s billionaire founder considers these “really dumb”⁶, however, reckoning his EV and domestic battery storage combination will prevail. In reality, the two might well complement each other. As autonomous (self-driving) technology kicks in, we might whizz around town in pay-as-you-go EV ‘pods’ but rent or lease an FCV for longer journeys or rural living.

No-one considers a hydrogen switch-over straightforward. But ramping-up plug-in infrastructure and power generation won’t be easy, either. Whilst the UK has recently committed £23m (US$30.4m) towards re-fuelling facilities⁷, ‘hydrogen highways’ in Scandinavia and North America have seen slow take-up. A (relatively) painless solution might therefore be to target buses, taxis and delivery vans: currently diesel-powered, these contribute disproportionately to urban emissions; hydrogen re-fuelling at a handful of depots might be achievable in the short-term.

What are the challenges facing industry?

UK oil consumption is already trending downwards. Whilst EV take-up is still low (but rising), this fall is chiefly due to conventionals getting more efficient⁸: we’re driving further than ever but on less fuel. Reflecting this globally, OPEC predicts only a modest consumption increase up to 2040⁹. And the oil majors are even more pessimistic: despite anticipating a doubling in car numbers (largely from developing nations), BP envisages largely static demand. Again, that’s mostly due to improvements in conventionals¹⁰.

Whilst ‘big oil’ stands accused of ignoring the unfolding energy revolution (perhaps wary of spooking investors), it is slowly beginning to respond. Shell recently committed to hydrogen via a 10 MW ITM electrolyser at its Rheinland Refinery Complex¹¹and, also in Germany, to a network of re-fuelling stations. BP is also looking at similar refinery ‘greening’ options with Uniper¹². In the US, ExxonMobil continues to evaluate advanced biofuels and hydrogen options¹³.

Scotland reflects the opportunities and challenges of transition. In Aberdeen, the UK’s oil capital, Europe’s largest hydrogen bus fleet is expanding further and has been joined by a handful of car-club Toyota Mirais¹⁴ – more on those later. And a diversified, 30-mile energy corridor, Energetica¹⁵, is being established. Whilst critics note it still lacks the intended refuelling facilities¹⁶ and that the city relies upon refinery hydrogen, these are early days with further investment and integration required. Further north, Orkney’s splendidly-named Surf-n-Turf¹⁷ initiative proposes using tidal and wind power to generate hydrogen for electricity, heating and even local ferries. In doing so, it exemplifies how small, localised generation might replace giant refineries.

And what are the engineering opportunities?

Over the past decade, UK waters have seen some of the world’s largest offshore windfarms installed in over-lapping proximity to existing gas fields. Already, the economies of logistics sharing (supply boats and helicopters) are already helping older gas fields remain viable. But the real gains are to be made in the inter-connection of these two offshore parallel energy systems.

Gas-to-wire technology would see gas from offshore fields used to generate electricity locally with export to shore via nearby windfarm power cables. Fast-responding open-cycle gas turbines could ‘peak shave’ grid demand and compensate for drop-off in windfarm output. Relocatable, modularised power stations (floating or jack-up) could be deployed relatively quickly to access late-life fields or currently stranded reserves across the region.

Conversely, power-to-gas (P2G) would see renewables electricity generate hydrogen (via electrolysis) for export to shore via existing offshore gas pipelines. As we’ll see shortly, the Dutch are examining such options although early electrolysers remain limited by cost and technical (space, weight, output) considerations.

Meanwhile, Cadent proposes hydrogen to ‘dilute’ the methane supply to industrial users in the Liverpool-Manchester Hydrogen Cluster¹⁸ thus reducing carbon dioxide emissions without extensive infrastructure modifications. Emissions from its own new SMRs would be stored in spent gas fields in Liverpool Bay. Such infrastructure re-use also helps reduce the UK’s anticipated £60bn offshore decommissioning bill¹⁹ roughly half of which sits with the taxpayer.

Netherlands – tackling similar challenges

Across the North Sea, the Netherlands faces similar challenges. Spurred by falling domestic gas production (North Sea fields in natural decline plus earth tremors impacting the giant onshore Groningen field) plus the grid implications of growing offshore wind capacity, the Dutch are actively investigating their options.

Whilst offshore oil & gas platforms can be as power-hungry as a small town, their generating costs and emissions are often disproportionately high. With operators such as Shell now investing in adjacent windfarms, the option now exists to ditch gas turbines and instead draw on renewable power. (Meanwhile, the Norwegians are already a step ahead with new platforms running on hydro-electric power via a cable from shore²⁰.)

But Dutch ambition is at the fore in hydrogen. A Gasunie pilot project will soon use solar power for electrolysis. The resultant hydrogen can be stored in natural underground salt caverns (already used for gas storage) and transported by adapting the existing gas network ahead of use in power generation, transportation or the chemical industry²¹.

Another concept (from the Energy Delta Institute) would see gas platforms re-born as electrolyser stations integrated with nearby windfarms²². More ambitious still are the proposed artificial, Power Link Islands for large-scale P2G operations and distribution²³. These would tackle not only climate and pollution concerns but also energy security. Once backed up by hydrogen, renewables could begin to address Europe’s dependence upon Russian energy²⁴.

Japan – a major commitment to hydrogen

But for a major commitment to hydrogen, look to Japan, an energy-hungry nation lacking indigenous fossil fuels and facing a post-Fukushima loss of faith in nuclear. Based on its 2014 Strategic Energy Plan’s 3E+S (Energy Security, Economic Efficiency, Environment + Safety) principles, Japan aims to have 40,000 hydrogen vehicles and 160 filling stations ready to showcase at the 2020 Tokyo Olympics²⁵ with 800,000 by 2030.

Australian lignite coal (a cheap, abundant energy source) would be converted via established gasification and reforming processes. The resultant carbon dioxide would be stored locally with the hydrogen shipped to Japan. With infrastructure in place, alternative sources, including local renewables, could follow.

Japan’s massive car industry is also on-board: Toyota’s Mirai is the world’s first purpose-built hydrogen FCV. It can even power homes, a potential life-saver in an earthquake-prone nation²⁶. But whilst economies-of-scale would tackle its £60,000 price-tag²⁷, some warn of Japan creating unique ‘Galapagos’ energy solutions which cannot be marketed globally²⁸.

Japan’s experience also exemplifies the engineering challenges of hydrogen transportation and storage. Whilst Kawasaki promote liquefied solutions for bulk shipping²⁹, other concepts include the Chiyoda’s reversible toluene hydrogenation and the conversion to ammonia³⁰. Meanwhile, a Mirai carries just 5 kg of hydrogen (providing a 300-mile range) but requires a sophisticated 90 kg carbon-fibre tank³¹ to prevent leakage and ensure crash safety.

Toyota’s Mirai is the world’s first purpose-built hydrogen FCV (Toyota)

What might politicians learn from this...and how might engineers contribute?

Investing in technology will be key to a successful UK energy transition. As part of its industrial strategy, the government recently announced the £246m Faraday Challenge³² to boost battery development. More may be required to match global competitors. Equally important are skills: on a practical level, East Anglian colleges now train apprentices on both offshore wind and gas installations. Flexibility will be key in an increasingly diversified sector.

A generation ago, politicians promoted diesel cars as a means of hitting carbon dioxide targets. Instead, their nitrous oxides and particulate emissions stand now accused of contributing to 40,000 premature UK deaths annually – an admittedly contentious statistic³³. And, thanks to ever-growing low emission zones (LEZs), many cars are subject to punitive tariffs or, as in Paris³⁴, banned altogether. In their desire to clean up (both air quality and votes), politicians risk creating confusion. (Over the course of writing this piece, I was tempted out of my ageing, petrol-guzzler by a scrappage scheme: I won’t be thrilled if my hybrid loses its London congestion charge exemption too soon.)

Meanwhile, in an earlier article, I discussed the outspoken Detroit motor engineer, Bob Lutz³⁵. Whilst Lutz wanted to seize the initiative in economy, ‘the suits’ instead demanded more full-size SUVs and pick-ups which dodged fuel efficiency regulations via re-classification as trucks. Predictably, when oil prices spiked, customers deserted and General Motors headed to Washington for a bail-out. Legislation needs to be framed carefully.

None of the above difficulties were unpredictable but we engineers need to ensure our voices are heard in order to inform the debate and help drive change. There isn’t one single solution to our energy challenges out there. But let’s see if hydrogen might have a useful role to play.