We're still in the dark over high-speed rail

Another day, another voice criticising the government’s plans for high-speed rail. This time it’s the National Audit Office, which argues the business case and the strategic reasons for developing HS2 haven’t been made clear enough.

Yesterday’s report concluded that the Department for Transport has put a high emphasis on the journey-time savings without clearly showing how this will benefit the economy, particularly outside of London.

The NAO also says it isn’t clear whether the business case presented so far includes the second phase of the scheme connecting Birmingham with Manchester and Leeds, which has a stronger but less certain economic case because designs are less well developed.

You don’t need to convince The Engineer that the plans for HS2 and the reasons for building it haven’t been laid out clearly enough – we’ve been saying so for a year. The NAO report really just underlines the point that what’s needed is more information.

Despite presenting itself in a defensive way (such is politics), the government in a sense agrees with this point. Transport secretary Patrick McLoughlin released a statement saying the NAO’s argument ‘depends too much on out of date analysis and does not give due weight to the good progress that has been made since last year’.

The DfT told The Engineer a more advanced business case was already underway and would be finalised later this year. And it claimed the NAO had largely overlooked the case for the second phase of the project (it seems like everyone’s doing this).

In response, the NAO said its report was based on the latest available data, and at this point the whole thing threatened to descend into political squabbling.

The difficulty is that a project as huge, costly and time-consuming as HS2 is very difficult to effectively analyse. The latest consultations on the scheme will likely conclude before we’re able to see the latest data – which might help convince people of HS2’s benefits – but even once we have it, how much faith can we really place in it?

Take the argument that the construction of a high-speed rail network will reduce carbon emissions by encouraging people to take the train rather than fly or drive. As the IET’s transport policy adviser, Chris Richards, pointed out to me (and, indeed, people have been saying for years), it’s not actually clear high-speed rail travel would make substantial carbon savings.

Even if we shift to low-carbon electricity generation, HS2 trains will need much more energy than current ones to reach their high speeds. Plus, we don’t even know HS2 will encourage a significant number of people to drive or fly less given how much more expensive train travel already is and our inability to reliably predict future oil prices.

Similarly with the business case, conflicting information abounds on whether effectively bringing Manchester, Leeds, Birmingham and London closer together will help regenerate the North of England or suck more wealth and talent into the South, pulling investment away from smaller towns in the process.

Chris Richards, who added that the IET has long been highlighting the flaws in the government’s analysis, said the new report raised memories of a previous NAO study of HS1 (the Channel Tunnel rail link).

‘The original business case for HS1 included things like journey time savings but the report found the project cost exceeded the value of these time savings. Unfortunately for HS2, they’ve used exactly the same rationale. In 2026 we could suddenly turn around and find the project costs completely outweigh the benefits.’

The thing is we don’t now see HS1 as having been a big waste of money. Even if the line hasn’t lived up to all its expectations, we generally view the benefits of a direct high-speed connection to Europe as worthwhile.

So perhaps we need to start stripping away the tangential arguments and looking simply at what is the best way to match rail capacity to demand. We need to see HS2 as what it is: not a way to shave 20 minutes off a trip from London to Birmingham or a carbon-cutting measure but an attempt to improve the wider rail network and inject some international prestige into our infrastructure.

Many people, including the NAO, say the arguments for alternative options (another upgrade of the West Coast Mainline, for example) haven’t been properly explored. Engineers at the IET, IMechE and other organisations disagree. Ultimately it becomes a political decision based on how much the British public and business community want a big upgrade of the railways at a cost of £30bn.

This article first appeared on The Engineer. 

Energy storage: a question of balance

Developing viable energy storage technologies is one of the big engineering challenges when it comes to cutting carbon emissions, and yet the issue has received relatively little mainstream attention or support.

We desperately need energy storage to make renewable generation more practical and cost-effective, to remove the sight of wind turbines shut down during windy but off-peak times and reduce the need for backup fossil-fuel power when renewable energy runs short.

So the announcement that 12 projects have been put through to the first stage of the government’s energy storage competition is very welcome, even if the amount of money allocated at this feasibility stage (£500,000) is relatively small.

Those groups that reach the second, demonstration phase of the competition will be competing for a share of £17m ­– a more substantial sum but one that still requires plenty of private investment if these technologies are to be brought to a commercial level.

What’s perhaps most interesting about the winners list (and about the field of energy storage research in general) is the breadth of technologies identified as possible solutions. It’s both an opportunity and an obstacle: the UK is bursting with ideas of different ways to capture energy for different scenarios, but that means we need more funding to develop them.

In particular there are a huge number of battery technologies put forward as having potential for grid-scale storage, from lead acid to lithium ion to more unusual concepts. They’re costly but offer very high efficiencies, sometimes up to 95 per cent or more.

The one chosen to go forward in the DECC competition is for a vanadium redox flow battery. A group led by Wokingham firm REDT hopes to built a 1.2MWh system on the Isle of Gigha off the west coast of Scotland to store surplus energy from a wind turbine for use in the local network. The company claims the technology offers 75 to 80 per cent efficiency depending on duty cycle at a cost of £1.7m to £1.9m per MW, and says this is a lower cost over the 10 to 15-year life of the system than any other battery storage.

But several other groups in the competition are hoping to bring the cost of battery storage down by using existing batteries. The Aston University-led group plan to combine new lithium titanate batteries with old electric vehicle units to provide grid-balancing services: the second-hand batteries will provide most of the capacity while the new ones will cater the rare occasions when National Grid needs up to 30 minutes of extra power.

Yuasa Battery Europe, meanwhile plans to convert existing uninterruptible power supply (UPS) equipment used for backup in industry by replacing lead acid batteries with lithium ion ones, possibly pre-used from electric vehicles. The electricity doesn’t go back to the grid but it would help with balancing and would cost an estimated £600,000 per MW of capacity.

Other competition entries make use of batteries as part of an energy and money-saving domestic service, such as the Maslow system that Moixa Technology hopes to install in 750 homes. It stores energy from the grid overnight or from solar panels on the roof for use in a DC lighting and electronics system, but can also help with grid-level storage and balancing.

Alongside the batteries there are numerous other storage mediums being proposed. Liquid air storage might sound like it should be an experimental technology but could actually reach a commercial scale if it goes through to the next stage of the competition. Its efficiencies are below those of batteries but can be increased if waste heat (and cold energy) streams from power plants or other industrial sources are harnessed, and it uses a free medium (air) and well established liquefaction and evaporation technology. The firm developing it, Highview Power Storage, have even created a cryogenic system it says is the equivalent of a diesel generator powered by air.

Another alternative in the competition is storing energy by producing methane, which can then be burnt to produce electricity or used in industrial processes. Hydrogenics Europe wants to build the first power-to-gas plant in the UK, and the first power-to-methane plant based on biological methanation in the world at a waste water treatment plant. It says the efficiency is 58 per cent, rising to 78 per cent if heat from the process is recovered. The costs are currently £1.4m/MW but the company claims this could fall to £800,000/MW.

Using gas (air, methane or hydrogen) means you can effectively move the energy from where it is captured to where it is needed, and the technology is easily scalable and less location-dependant than pumped hydro storage or compressed air systems that pump into caves. But we’ve yet to see whether the efficiencies or costs can make the technology viable as a widespread commercial solution.

There’s also another more unusual concept amongst the competition winners: using gravel as a storage medium by carrying it to the top of a hill in buckets attached to what looks like a ski lift. It’s a messy idea (literally and perhaps metaphorically) but its US inventors Energy Cache claim it beats pumped hydro and compressed air for cost and performance and is also more easily sited. The company has yet to respond to The Engineer’s requests for more details but we’ll bring you a more in-depth report when we can.

Looking at the huge range of ideas for energy storage suggests two things: that not all of them will be successful but also that there probably won’t be a single winning technology. Just as with renewable energy generation, we’re likely to need multiple ways to store energy. Let’s hope the UK can provide the necessary support to turn our wealth of ideas into viable solutions and businesses.

This article first appeared on The Engineer.