scotview wrote:You are presenting future solutions, we are living in the now, where hospitals, chronically ill and old folkies need guaranteed supply, fact.
The risk of sailing so close to the wind (pardon the pun) increases the risk of rolling blackouts, system instability or total regional blackout. Even if we get suitable backup storage, of whatever magnitude, the size of which will be another big debate in itself, it won't be available next week.
It won't be available next week - but at the same time it's not decades away either, it's a few years away. And we don't *need* it next week, but we will need it in the next few years.
Yes we're going to be winging it for a few years as the margins get a lot thinner than are desirable - but at the same time I remember arguing on TMF with people who thought that 5-10% renewable would hopelessly destabilise the National Grid, at a time when NG themselves were saying that the grid would be good for at least 20% renewable (and plenty of people were poo-pooing even that). We've come a long way since then, and we understand much better the factors that matter when thinking about this stuff - IIRC NG are now saying that the current grid should be good up to 70-80% renewables and they're working on how to get to 100% which will probably involve some of the things discussed by Ruhnau and Qvist.
But the fact we are winging it is less to do with technology (we're not waiting for nuclear fusion or warp drives to rescue us) than other factors like finance and the regulatory environment. Covid has been part of that but you can't ignore the way Brexit has sucked out government's capacity to get stuff done. For instance I've a friend who's a civil servant who's worked on energy policy at a fairly senior level - but in the last 6-7 years they've spent 2/3 of their time exclusively on Brexit, and another year working on another project where government had made promises without thinking how to deliver it. And then you have all the department reshuffles
scotview wrote:Surely a strategy of balancing intermittent supply with secure and immediate back-up would (have been) be the way to go.
Err - that's what we are doing?
But the last year has taught us a few things about what secure and immediate backup looks like - gas now longer looks like the cheap and reliable source of electricity that it used to be, the French woes have showed how nuclear can be less reliable than offshore wind, and Hinckley Point is a warning about depending too much on single large projects, a strategy of more-but-smaller projects is more robust.
To give a ballpark estimate,
Hinckley Point is now forecast to cost £32.7bn for 3.2GW that let's say will have a 90% capacity factor (nuclear has quite a bit of downtime for refuelling and maintenance).
That compares with Dogger Bank costing
£9bn for 3.6 GW, so £8bn for 3.2GW, and let's say a 45% capacity factor for convenience (although eg
Hywind has managed up to 57% capacity and SSE seem to be implying something similar when they say that each of the three 1.2GW bits of Dogger Bank will generate 6TWh annually). So £16bn spent on Dogger Bank-alikes would generate 6400MW at 45% capacity, compared to Hinckley Point generating 3200MW at 90% capacity.
Form seem to be implying $20 capex per kWh stored, so $20k/MWh, which for a 100-hour system implies $2m per MW of output. So 100 hours of backup (in reality more as you wouldn't need to give 100% backup in the middle of the night during a multi-day windless period) for 3200MW would cost $6.4bn - assume 1:1 exchange rate and it's £6.4bn.
So one 3.2GW windfarm, plus 100 hours of 3.2GW batteries, plus another windfarm to fill the batteries and directly increase the % of time during which you generate 3.2GW when winds are low but not zero, to give you 3.2GW at 90% capacity factor like Hinckley Point - all that costs £22.4bn, or <70% of the cost of Hinckley Point.
Now in the real world you wouldn't want 100-hour coverage of 100% of your capacity, you'd want more of a mix along the lines of Ruhnau and Qvist - but the above gives you an idea given what's possible with technology that is coming online this year (Dogger Bank) or is entering production next year (Form iron-air), and you've still got an extra £10bn to play with compared to Hinckley Point.
Yes, UK energy policy has been a mess for 20+ years, and government has been completely distracted by other things since 2016, and as a result we are winging it far more than we should do. And as in 2022 we may end up cutting it a bit too fine on some occasions. But there's lots to be optimistic about as well, and the constraints are more political and financial than technological.