Articles by Chris Goodall

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‘The EPR is safe, very safe’ said Tony Roulstone at a lecture in Oxford on Tuesday 21st October. But the complexity of the design means it is extraordinarily difficult to build. This type of reactor is, he said, perhaps in an unguarded moment, ‘unconstructable’.

Roulstone, who runs the Master’s programme in nuclear engineering in Cambridge, described the proposed EPR nuclear power station at Hinkley Point as similar in concept to ‘a cathedral within a cathedral’ which would stretch the ability of any business to build it. With two sets of 6 metre thick concrete walls towering 70 metres above Somerset, the building would survive a direct hit from an airliner but at a very high price in terms of construction timetable and cost. Read the rest of this entry »

UK Environment Secretary Liz Truss spoke of her dislike of solar PV installations in fields. In an interview last week with the Mail on Sunday, she said

‘They are ugly, a blight on the countryside, and …. are pushing production of meat and other traditional British produce overseas.’

She went on

‘I’m not against them per se – they’re fine on commercial roofs and school roofs – but it’s a big problem if we are using land that can be used to grow crops, fruit and vegetables. We import two-thirds of our apples, and using more land for solar panels makes it harder to improve that’

As far as I know, the argument that supermarket apples come from New Zealand because of the shortage of land caused by solar PV in the UK is a new one. A quick look at the numbers doesn’t support her conclusion.

Is solar crowding out agricultural use of UK land?

  • The UK now has about 5 gigawatts of solar PV
  • About 40%, or around 2 gigawatts, is mounted on the ground.
  • Some of these solar farms are on disused land such as old airfields or abandoned clay pits.
  • No more than about 1.5 gigawatts is on agricultural land on which crops are grown or animals graze.
  • These PV farms occupy a total of about 3,000 hectares, or around 2 hectares per megawatt.
  • About 17.2m hectares are used for agriculture of some form in the UK
  • Ground mounted panels therefore use about 0.02% of all agricultural land in the UK.

Specifically, is apple growing in decline because of solar PV?

  • Orchards currently occupy about 23,000 hectares in the UK, about seven times the land used for solar PV.
  • This number is the same as in 2013
  • And is up about 15% from 20,000 hectares five years ago.
  • So the rapid growth in solar PV has had no effect whatsoever on the land used for orchards.
  • This is unsurprising. Almost all large PV farms on agricultural land are sited in areas normally used for the grazing of livestock not growing fruit.
  • Two farmers I have spoken to say that PV improves the health, lamb survival and weight growth of sheep because the panels provide shelter from wind, rain, sun, snow and birds of prey while not significantly affecting grass growth.

When the UK power cuts arrive, they will hit at around 4.30pm on midweek evenings in December and January. A region of the country will be disconnected for two or three hours until demands starts to fall after the early evening peak. But, in theory, excess power from domestic PV installations that would otherwise be spilled onto the grid could be mopped up by storage batteries. Can electricity stored in these domestic battery systems make these power cuts less likely? And can householders insulate themselves from the impact of electricity outages by buying a storage system? Or are batteries too expensive to make it worthwhile? 

The Sonnenbatterie 4.5 kWh battery pack

The Sonnenbatterie 4.5 kWh battery pack

To make a substantial difference to the likelihood of power cuts, batteries would need to supply perhaps half a gigawatt of power for three hours. That’s about 1% of UK peak winter demand. This means batteries in 500,000 homes (2% of UK total) each delivering 1 kilowatt. We’re some years, possibly some decades, away from this. But pessimism shouldn’t be overdone; the UK already has 500,000 PV equipped houses, almost all of which were installed within the last five years. In other words, if the incentives are right, half a million homes will quickly take on a new technology. And a battery pack is a lot easier to fit than PV panels. However, at today’s battery prices, we’re not at the point where the financial returns obviously justify the investment. Read the rest of this entry »

It only has symbolic significance, but at half past nine this morning wind was supplying more electricity to the national grid than nuclear.(1) For a few minutes, the gusts over the western side of the United Kingdom supplied more than 6 gigawatts and a temporary slight dip in nuclear output meant that wind was more important for electricity supply than the UK’s ageing nuclear fleet. The new record came a few hours after news stories about new cracks in the graphite blocks of one of the reactor at EdF’s Hunsterston plant. We’ll see more and more days when wind power beats the geriatric nuclear fleet.

A couple of other features of electricity supply over the past 24 hours are worth mention. At 4am this morning, the price of power (as indicated by the sell price in the ‘balancing market’ that keeps electricity supply and demand in balance) fell to a low of just over £1 per megawatt hour. They were basically giving the stuff away. Even at this time of the morning electricity generally sells for thirty times this amount. The high volumes of wind-generated electricity caused substantial disruption to the working of the power market for a few hours.

At almost the same time, we saw the interconnector between France and England change the direction of flow. Normally France pumps almost two gigawatts into the UK. For a few hours the UK exported power instead and the interconnector took 2 gigawatts to France. It’s difficult for outsiders to be sure of this but the National Grid appeared to also curtail (shut down) a large fraction of UK wind supply.

These related events matter more than the symbolic event that happened at half past nine. They show just how challenging the future of electricity supply is going to be and how urgently action is needed. Yes, the France interconnector took the temporary surplus off to the European grid early this morning for an hour or so. But the operators of the Grid needed to use almost the full capacity of the interconnector. As wind power grows, Atlantic storms risk becoming much more difficult to manage.

We need more interconnectors, more storage and, please, a way of converting surplus electricity into other usable fuels such as gas. Otherwise all that wind power investment is going to be largely wasted in the winter months.

(This article was published on The Guardian web site on Monday 6th October)



(1) Before counting the power from smaller wind farms attached to the networks of district operators)

A solar farm with a contract to sell electricity is almost the lowest risk investment a pension fund can make. Only index-linked government bonds beat its reliability. As long as electricity prices are contractually secure, PV resembles nothing so much as an annuity, a guaranteed flow of money that arrives every month for 25 years. Gradually, the financial markets are realising what a superb asset PV can be, particularly for pension funds needing to match long streams of liabilities. As a result, the cost of capital for solar farms is falling. It needs to fall much further.

It cannot be stressed enough how important this is. This week’s IEA report, which finally ended the Agency’s long-standing contempt for PV and large scale solar thermal technologies, put it bluntly. At today’s prices and construction costs, PV produces electricity in good global locations at around 6 US cents per kilowatt hour if interest on the capital is assumed to be 0%. Assume the cost of capital is 9% per year and the cost more than doubles to over 12 cents. At this level, interest payments are more than half the cost of solar PV. Read the rest of this entry »

Much of the UK government’s case for backing renewables comes from the view that it will save money in the longer term as fossil fuels become more expensive. The arguments for increasing prices for gas, oil and coal have become frayed in recent months. Coal demand has stabilised as China begins its long awaited move to use smaller volumes of imported fuel and to switch to less polluting forms of power generation. The need for oil has been compressed by falling world economic growth and gas is being undermined by increased supplies.

Governments tend to be reluctant to adjust price forecasts. It might undermine investment incentive. To react too soon to market trends can suggest insecure feelings about the quality of the forecasts.

DECC bought out new numbers today. Understandably, given the scale of the change, there was no accompanying text. Just a small Excel worksheet giving the forecasts for the three main fuels. A quick look at the table doesn’t suggest much has changed. The numbers for 2035 are similar to the figures produced a year ago.

It’s five years out that the real differences appear. Coal prices in 2019 are expected to be 23% lower than they were forecast this time last year. Gas and oil are both 21% down. Given that DECC issued 17 press releases today, the lack of media attention isn’t surprising. Nevertheless, these are really substantial changes in the medium term outlook. And they add yet another dimension of uncertainty for investors in renewable technologies.

Electricity is expensive to store in large quantities. The largest battery pack in North America has just opened this week at a cost of about $50m for 32 MWh of lithium-ion cells. That’s over $1,500 a kilowatt hour, several times the cost of batteries in electric cars. (I presume the reason for the high cost must be the sophisticated electronics necessary to tie the DC battery system to the local grid).

The new plant is sited at one of the substations serving the huge Tehachapi wind farms in Southern California. 600,000 individual batteries wired together in a 500 square metre warehouse are helping to stabilise the output of the five thousand turbines in this important wind province.

Tehachapi Battery Storage

Tehachapi Battery Storage

The UK’s largest storage battery is being built in Leighton Buzzard, north of London, and is due for completion by the end of 2014. This 10 MWh plant is costing about £20m, partly paid by Ofgem and partly by the local operator UK Power Networks. The cost is over twice the price per kilowatt hour of the Californian battery.

Adding the gigawatts/gigawatt hours of short term storage that we need is going to cost huge sums. Batteries will get cheaper, of course, particularly if Tesla continues to invest in enormous factories in the US. But even at $250 per kilowatt hour of storage capacity – one estimate of the likely cost of Tesla batteries within a few years – a gigawatt hour will require expenditure of $250m. That buys the capacity to store about a minutes worth of UK peak electricity need.

One alternative to lithium-ion batteries is an expansion of pumped hydro. Two water reservoirs at different heights are linked and reversible turbines are installed. When electricity is cheap, water is pumped uphill to the top reservoir. At times of high power demand the water flows back downhill, turning the turbines and producing electricity. The UK has had a large pumped hydro plant at Dinorwig in Snowdonia for thirty years.

A new company, Quarry Battery, has just raised another round of seed money to push its own Snowdonia project forward. £3m will enable the company to carry out engineering costings and other preparatory tasks for its scheme to turn two disused deep slate quarries into the upper and lower reservoirs of a pumped hydro plant. Read the rest of this entry »

At 5.30 in the late afternoon the average UK house is using about 130 watts of electricity to power lights. In the winter months this number rises sharply, probably to around 200 watts. 27 million households are consuming over 5 gigawatts of electricity just for lighting in the early evening of the darkest month.

The maximum need for electricity last year occurred just after 5pm on November 4th when the major generators delivered almost 53 gigawatts. At the moment of highest electricity need, domestic lighting was therefore using about 10% of the country’s power production. The easiest way of cutting this is by banning halogen bulb sales and obliging consumers to replace them with equivalent LEDs.

An LED bulb that could replace a standard halogen ceiling light

An LED bulb that could replace a standard halogen ceiling light

As conventional power stations close, the gap between the total generating capacity in the UK and peak winter demand is narrowing sharply. A ban on halogen lamps will dramatically improve the UK chances of ‘keeping the lights on’ in winter by shaving the top of the daily winter peak of power demand.

Halogens are not quite as inefficient as the old fashioned incandescent bulb but they use far more electricity than LED equivalents. A 35 watt bulb can be replaced by 5 watt LED of almost identical light quality. Many kitchens and living areas contain several hundred watts of halogen bulbs and all this lighting could be replaced by equally effective LEDs.

Cutting domestic lighting demand is the simplest way of reducing the maximum need for electricity. And it would reduce consumer bills and make a substantial dent in the need for electricity users to pay (indirectly via the so-called ‘capacity mechanism’) for fossil fuel power plants to stand waiting just in case the other generators couldn’t supply enough power. In addition, the reduction of peak demand would cut the need for extremely expensive grid upgrades. There is real social value in moving the country off halogen bulbs as fast as possible. Read the rest of this entry »

Schematic of the Joule plant in Hobbs, New Mexico

Schematic of the Joule plant in Hobbs, New Mexico

Scarred by the failure of first generation biofuels and by the increasingly bitter controversy over the burning of imported biomass at Drax and elsewhere, the UK has backed away from research into using biological materials for energy conversion or storage. This behaviour is mirrored across Europe. Outside the US, research into using natural materials has almost ceased as concerns over the diversion of land from food production and low carbon savings have overwhelmed the case for increased renewable energy.

This is a mistake, and possibly a tragic one. In sunny parts of the globe, solar PV may provide the cheapest source of electricity. But PV doesn’t provide either reliable 24 hour power or a source of liquid fuel for transport. Since electricity is typically provides less than 40% of total energy demand, the world needs to find inexpensive low carbon sources to meet other needs. Biological sources of energy are vital, not least because they can both store power (thus complementing intermittent sources such as PV) and can be converted to high density liquid fuels suitable for transport. A piece of wood is a semi-permanent store of solar energy and can be converted – albeit expensively at present – to a liquid hydrocarbon. Algae are similar. But work on even relatively simple technical problems such as improving the slowness of the breakdown of cellulose molecules in anaerobic digesters simply isn’t taking place in the UK.

By contrast, this note looks at Joule Unlimited, a seven year old US company that is making ethanol and other fuels from CO2, sunshine and water. Like many other US bioenergy companies, Joule has raised what to European eyes look like prodigious amounts of capital. But the $160m of investors’ money has bought what seems like exciting intellectual property. If Joule can do as it promises and produce transport fuels for less than $50 a barrel of oil equivalent, it can undermine the conventional supply of oil, a market currently worth about $8bn a day.  Read the rest of this entry »

A wind entrepreneur wrote to me last week pointing to the increased variability of wind speeds over the UK. Until recently, he wrote, average monthly wind speeds only very infrequently departed more than 30% from the norm from the month. In the last year, however, he said that we’ve had two months of very high speeds (more than 30% greater than the monthly average) and one very low speed period (30% less than the average for the month). This matters; greater variability of output from wind turbines means more need for backup resources.

Does the data match the entrepreneur’s instinct that variability is increasing? A quick look at average wind speeds since the beginning of 2001 argues it does. The average month now varies about 13% from the norm, up from 9.5% in 2001. This isn’t a large amount, and the data doesn’t suggest a very clear trend, but if variability is increasing it will add to future problems balancing UK electricity supply. And higher winter wind speeds will cause more destruction, as they did over many parts of the UK in February of this year.

Read the rest of this entry »

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