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Is there an energy bubble?
By Dr Andrew Physick, Engineering Team Lead
The uptake and use of hydrogen has to happen, for the environment and people’s health and well-being, just as much as for energy security. Hydrogen isn’t the golden bullet for all energy needs, but it is a critically essential part of the bigger picture, a part that can’t easily be substituted by other fuels.
Decarbonising the Grid
CO2 is released to the atmosphere from all of the generating sources connected to the national grid,. The 2021 Energy White Paper details targets to fully decarbonise the grid by 2035.
Crunching the numbers, in 2021, grid demand was 334 TWh, with an applaudable ~40% of our power coming from renewable energy. This does vary, but let’s take ~133 TWh for that for now. Again, figures do vary, but the fossil fraction stands at a little over 41%, or ~139 TWh. Just to decarbonise the grid, as is, we need an additional 139 TWh of capacity on demand, by 2035.
Electric Vehicle Uptake
There were 32.7 million passenger cars on UK roads as of 2020. With the ban on sales of new conventional petrol and diesel vehicles by 2030, there is expected to be a transition to EV’s. If even a quarter are replaced by electric by 2035, that’s 8.2 million electric passenger cars alone. The average distance cars drive in the UK is 20 miles per day or approximately 7,400 miles per year. That’s potentially 60.5 billion electric miles driven per year in total in the UK. In perfect driving conditions, electric cars consume ~0.25 kWh per mile averaged over the entire journey, so 1,850 kWh per car per year, or approximately 15 TWh. That still isn’t the whole picture, charging batteries of electric cars isn’t 100% efficient either.
Reported figures range from 85% in optimal conditions to as low as 60% in sub-optimal conditions. Taking the conservative optimal number, the additional grid demand for charging electric passenger cars could be 17.8 TWh.
The Nuclear Conundrum
By next year, five of the remaining six AGR nuclear reactors will be fully disconnected from the grid, the last AGR reactor by 2028, and the last PWD reactors by 2035. This represents an enormous reduction in low carbon grid capacity of 66.5 TWh. Yes, there are plans for up to eight new nuclear plants in the UK to cover this loss, but basing the speed of deployment on the ongoing Hinkley Point C project (2016-26, assuming no further delays), we should anticipate at least a 10 year construction program per new site, and we haven’t started construction of most of these yet. I’m a big, big fan of nuclear (almost as much as I love renewables), but we have to be realistic in terms of timeframes.
Green Hydrogen
Green Hydrogen needs green power. And a lot of it. If electrolysers were 100% efficient at splitting water, 33 kWh of electrical power would be needed to produce 1 kg of hydrogen. That is, 1 kg of hydrogen contains 33 kWh of energy at the lower heating value (LHV). Electrolysers aren’t 100% efficient however. Efficiencies could reach 80%, meaning ~42 kWh would be needed instead.
The green hydrogen market is forecast to grow, with backing from Government on multiple fronts and the 10 GW installed capacity target by 2030, with at least 50% of that capacity coming from electrolysers. 10 GW is approximately 87.6 TWh total per year. S&P Global predicts a much larger growth however, at ~330 TWh in their most conservative estimates, in which Net Zero targets aren’t even achieved. Big numbers indeed. Lets take a mid-range estimate, of 200 TWh of green Hydrogen, or 250 TWh of green electrical power needed for now.
Renewables
Summarising, that’s 139 TWh to decarbonise the existing grid, 17.8 TWh to cover EV’s, 66.5 TWh to cover the crossover of nuclear fleets, and taking a conservative mid-range number, an additional 250 TWh to cover green hydrogen. That is a whopping 473 TWh of additional low carbon power we could potentially need by the 2030’s.
Fortunately, the UK Government wants up to 438 TWh equivalent of renewable installed capacity by 2035. That’s installed capacity, not actual output capacity.
Now asking how many we need, well wind turbines are already approaching the Betz efficiency limit and tip speed limit, so are likely approaching both size and cost plateaus. So taking an average 2 MW turbine spacing of 2 per km2, we are talking a wind farm of 16,873 km2 (Wales is 20,779 km2, for comparison).
The Government states it takes at least 13 years to build an off-shore wind farm of current, modern sizes, so even if a new wind farm was announced today, the 2035 deadline would already be missed for that farm. And I suspect no one is planning on announcing a wind farm the size of Wales, just yet anyway. So timeframes don’t align, even if we start building additional massive wind farms right now.
There seems to be a worrying power gap between the late 2020’s and 2030’s. What will be sacrificed first – power to homes or businesses, power to EV’s, or power to green hydrogen projects? I can take a pretty good guess which of those would be political suicide, and what would suffer the first blow. Maybe we should be looking to diversify our hydrogen ambitions a little furthe.
Solution
The answer’s rubbish, literal rubbish. That is, waste can play a critical part in covering the shortfalls for green hydrogen, until the huge wind farm is built and new nuclear is smoothly purring away with that soft Cherenkov glow, and if used correctly, it can do this without placing additional strain on the grid. This can also play a part in decarbonising one of the most difficult to decarbonise parts of the grid, which is also the most polluting part – incineration.
The reason that incinerators are difficult to decarbonise, is that their use is currently not optional, and the scales involved are big. Primary fossil fuel isn’t dug out of the ground as their feedstock, and they can’t just be turned off, as they tie into an ongoing waste problem in the UK. Remaining landfill capacity is running dangerously low, and land is too precious to open new landfills. Every new landfill would be another local ecosystem destroyed.
Recycling rates are increasing, fortunately, which alleviates the strain and pressures slightly, but the process of recycling isn’t 100% efficient either. As recycling rates increase, the fraction of unrecyclable material also increases, and guess what will happen to that. Correct – it will be incinerated.
Wouldn’t it be great if there was a cutting-edge new technology available, to recycle, chemically and efficiently, that same unavoidable and non-recyclable waste, and which produces both hydrogen, and electrical power, at the point it’s needed. A technology that would support the already fragile grid as well as the emerging hydrogen economy. A technology that could be developed without the need for widespread infrastructure changes, whilst aiding in lowering the carbon intensity of the grid.
And wouldn’t it be even better if that same technology could separate out some of the carbon in the waste in an easy-to-handle, solid form, diverting it away from the atmosphere? And whilst we’re at it, let’s throw in to our wish list all the above but with a low water-use demand and a small footprint too.
Now here’s the clever bit, Powerhouse Energy has developed such a technology, based around a process called gasification, an Advanced Thermal Conversion technology. Powerhouse’s diversified modular gasification, or DMG, technology can do all of the above, bridging that critical gap and crossover period that has been identified, supporting the nation’s needs, in a more efficient and lower carbon manner.
This is technology that is ready to go right now. What we want is more people to learn about it, both the general public and at Government level. What it isn’t, is a magic wand that will fix everything, but it has the potential to make an impact where it can pull a big punch, in areas that are difficult to work in, where there aren’t many good options available. So, I invite you to share this article, view our website and learn a bit more about the good work we are trying to do here at Powerhouse Energy.