Archive for July, 2017

In a few large companies I observed the same phenomenon – over here are corporate dreams and over there is reality. Team – your job is to move reality over to where corporate dreams are.

It wasn’t worded like that. Anyway, reality won each time. Reality is pretty stubborn. Of course, refusal to accept “reality” is what has created great inventions and companies. It’s not always clear what is reality and what is today’s lack of vision vs tomorrow’s idea that just needs lots of work to make a revolution. So ideas should be challenged to find “reality”. But reality itself is hard to change.

I starting checking on Carbon Brief via my blog feed a few months back. It has some decent articles although they are more “reporting press releases or executive summaries” than any critical analysis. But at least they lack hysterical headlines and good vs evil doesn’t even appear in the subtext, which is refreshing. I’ve been too busy with other projects recently to devote any time to writing about climate science or impacts, but their article today – In-depth: How a smart flexible grid could save the UK £40bn – did inspire me to read one of the actual reports referenced. Part of the reason my interest was piqued was I’ve seen many articles where “inflexible baseload” is compared with “smart decentralized grids” and “flexible systems”. All lovely words, which must mean they are better ways to create an electricity grid. A company I used to work for created a few products with “smart” in the name. All good marketing. But what about reality? Let’s have a look.

The report in question is An analysis of electricity system flexibility for Great Britain from November 2016 by Carbon Trust. The UK government has written into legislation to reduce carbon emissions to almost nothing by 2050 and so they need to get to work.

What is fascinating reading the report is that all of the points I made in previous articles in this series show up, but dressed up in a very positive way:

We’re choosing between all these great options on the best way to save money

For those who like a short story, I’ll rewrite that summary:

We’re choosing between all these expensive options trying to understand which one (or what mix) will be the least expensive. Unfortunately we don’t know but we need to start now because we’ve already committed to this huge carbon reduction by 2050. If we make a good pick then we’ll spend the least amount of money, but if we get it wrong we will be left with lots of negative outcomes and high costs for a long time

Well, when you pay for the report you should be allowed to get the window dressing that you like. That’s a minimum.

The imponderables are that wind power is intermittent (and there’s not much solar at high latitudes) so you have some difficult choices:

I’ll just again repeat something I’ve said a few times in this series. I’m not trying to knock renewable energy or decarbonizing energy. But solving a problem requires understanding the scale of the problem and especially the hardest challenges – before you start on the main project.

As a digression, there is a lovely irony about the use of the words “flexible” for renewable energy vs “inflexible” for conventional energy. Planning conventional energy grids is pretty easy – you can be very flexible because a) you have dispatchable power, and b) you can stick the next power station right next to the new demand as and when it appears. So the current system is incredibly flexible and you don’t need to be much of a crystal ball gazer. That said, it’s just my appreciation of irony and how I can’t help enjoying the excitement other people have in taking up inspirational words for ideas they like.. anyway, it has zero bearing on the difficult questions at hand.

As the article from Carbon Brief said, there’s £40bn of savings to be had. Here is the report:

The modelling for the analysis has shown that the deployment of flexibility technologies could save the UK energy system £17-40 billion cumulative to 2050 against a counterfactual where flexibility technologies are not available

Ok, so it’s not £40bn of savings. The modeling says getting it wrong will cost £40bn more than picking better options. Or if the technologies don’t appear then it will be more expensive..

What are these “flexible grid technologies”?

Demand Management

The first one is the effectively untested idea of demand management (see XVIII – Demand Management & Levelized Cost) which allows the grid operator to shift peoples’ demand to when supply is available. (Remember that the biggest current challenge of an electricity grid is that second by second and minute by minute the grid operators have to match supply with demand – this is a big challenge but has been conquered with dispatchable power and a variety of mechanisms for the different timescales). I say untested because only small-scale trials have been done with very mixed results, and some large-scale trials are needed. They will be expensive. As the report says:

Demand side response has a key role in providing flexibility but also has the greatest uncertainty in terms of cost and uptake

However, with a big enough stick you get the result you want. The question is how palatable that is to voters and what kind of stomach politicians have for voter unrest. For example, increase the cost of electricity to £100/kWhr when little is available. Once you hear that a few friends received a £10,000 bill that they can’t get out of and are being taken to court you will be running around the house turning everything off and paying close attention to the tariff changes. When the tariff soars, you are all sitting in your house in your winter coats (perhaps with a small bootleg butane heater) with the internet off, the TV off, the lights off and singing entertaining songs about your favorite politicians.

I present this not in parody, but just to demonstrate that it is completely possible to get demand management to work. Just need a strong group of principled politicians with the courage of their convictions and no fear of voters.. (yes, that last bit was parody, if you are a politician you have to be afraid of voters, it’s the job requirement).

So the challenge isn’t “the technology”, it’s the cost of rolling out the technology and how inflexible consumers are with their demand preferences. What is the elasticity of demand? What results will you get? And the timescale matters. If you need people to delay using energy by one hour, you get one result. If you need people to delay using energy by two days, you get a completely different result. There is no data on this.

Pick a few large cities, design the experiments, implement the technology and use it to test different time horizons in different weather over a two year period and see how well it works. This is an urgent task that a few countries should have seriously started years ago. Data is needed.


Table 26 in the appendices has some storage costs, which for bulk storage “Includes a basket of technologies such as pumped hydro and compressed air energy storage” and is costed in £/kW – with a range of about £700 – 1,700/kW ($900 – 2,200/kW). This is for a 12 hour duration – typical daily cycle. These increase somewhat over the time period in question (to 2050) as you might expect.

For distributed storage “Based on a basket of lithium ion battery technologies” ranges from £900 – 1,300/kW today falling to £400 – 900/kW by 2050. This is for a 2 hour duration (and a 5-year lifetime). Meaning that the cost per unit of energy stored is £450 – 650/kWhr today falling to £200 – 450/kWhr by 2050. So they don’t have super-optimistic cost reductions for storage.

The storage calculations under various scenarios range from 10-20GW with a couple of outliers (5GW and 28GW).

My back of the envelope calculation says that if you can’t expand pumped hydro, don’t build your gas plants, and do need to rely on batteries, then for a 2-day wind hiatus and no demand management you would spend “quite a bit”. This is based on the expected energy use (below) of about 60GW = 2,880 GWhr for 48 hours. Converting to kWhr we get 2,880 x 106 and multiplying by the cost of £300/kWhr = £864bn every 5 years, or £170bn per year. UK GDP is about £2,000bn per year at the moment. This gives an idea of the cost of batteries when you want to back up power for a period of days.

Backup Plants

The backup gas plants show as around 20GW of CCGT and somewhere between 30-90GW of peaking plants added by 2050 (depending on the scenario). This makes sense. You need something less expensive than storage. It appears the constraint is the requirement to cut emissions so much that even running these plants as backup for low wind / no wind is a problem.

Expected Energy Use

The consumed electricity for 2020 is given (in the appendix) as 320-340 TWhr. Dividing by the number of hours in the year gives us the average output of 36-39 GW, which seems about right (recent figures from memory were about 30GW for the UK on average).

In 2050 the estimate is for 410-610 TWhr or an average of 47-70GW. This includes electric vehicles and heating – that is, all energy is coming from the grid – so on the surface it seems too low (current electricity usage is about 40% of total energy). Still, I’ve never tried to calculate it and they probably have some assumptions (not in this report) on improved energy efficiency.

Cost of Electricity in 2050 under These Various Scenarios



The key challenges for large-scale reductions in CO2 emissions haven’t changed. It is important to try and identify what future cost scenarios vs current plans will result in the most pain, but it’s clear that the important data to chart the right course is largely unknown. Luckily, report summaries can put some nice window-dressing on the problems.

As always with reports for public consumption the executive summary and the press release are best avoided. The chapters themselves and especially the appendices give some data that can be evaluated.

It’s clear that large-scale interconnectors across the country are needed to deliver power from places where high wind exists (e.g. west coast of Scotland) to demand locations (e.g. London). But it’s not clear that inter-connecting to Europe will solve many problems because most of northern and central Europe will be likewise looking for power when their wind output is low on a cold winter evening. Perhaps inter-connecting to further locations, as reviewed in XII – Windpower as Baseload and SuperGrids is an option, although this wasn’t reviewed in the paper.

It wasn’t clear to me from the report whether gas plants without storage/demand management/importing large quantities of European electricity would solve the problem except for too aggressive CO2 reduction targets. It sorted of hinted that the constraint of CO2 emissions forced the gas plants to less and less backup use, even though their available capacity was still very high in 2050. Wind turbines plus interconnectors around the country plus gas plants are simple and relatively quantifiable (current gas plants aren’t really optimized for this kind of backup but it’s not peering into a crystal ball to make an intelligent estimate).

The cost of electricity in 2050 for these scenarios wasn’t given in this report.

Articles in this Series

Renewable Energy I – Introduction

Renewables II – Solar and Free Lunches – Solar power

Renewables III – US Grid Operators’ Opinions – The grid operators’ concerns

Renewables IV – Wind, Forecast Horizon & Backups – Some more detail about wind power – what do we do when the wind goes on vacation

Renewables V – Grid Stability As Wind Power Penetration Increases

Renewables VI – Report says.. 100% Renewables by 2030 or 2050

Renewables VII – Feasibility and Reality – Geothermal example

Renewables VIII – Transmission Costs And Outsourcing Renewable Generation

Renewables IX – Onshore Wind Costs

Renewables X – Nationalism vs Inter-Nationalism

Renewables XI – Cost of Gas Plants vs Wind Farms

Renewables XII – Windpower as Baseload and SuperGrids

Renewables XIII – One of Wind’s Hidden Costs

Renewables XIV – Minimized Cost of 99.9% Renewable Study

Renewables XV – Offshore Wind Costs

Renewables XVI – JP Morgan advises

Renewables XVII – Demand Management 1

Renewables XVIII – Demand Management & Levelized Cost

Renewables XIX – Behind the Executive Summary and Reality vs Dreams

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