its time to chop the peak! 230215

IT’S TIME TO CHOP THE PEAK!

DOMESTIC ELECTRICITY DEMAND MANAGEMENT MADE SIMPLE, CHEAP AND CONVENIENT FOR ALL

Tom Langdon-Davies BSc (Eng.) FRSA

©March 2015

http://theintelligentplug.com

[email protected]



How to Close Power Stations - Easily

Cheaply and with No Loss of Comfort

It’s time!

• Time to make electricity affordable

• Time to keep electricity reliable

• Time to save the planet

If I told you that you could make a significant

contribution to doing this without even reducing how

much you use, and without any expensive equipment,

would you believe me?

Most people probably wouldn’t.

They might say there’s no such thing as a free lunch,

there must be a catch.

But there isn’t!



In the UK, every winter weekday, from 3 to 8pm,

peaking at around 5.30, we use seven large power

stations (7 Gigawatts) worth of electricity more than

we do at any other time. Why? Because some people

are coming home from school and from work, and it’s

getting dark. Most offices, factories and shops are still

working.

But here’s the good news – That peak, which is about

14% above the normal daytime level, can be easily

avoided, reducing bills, helping save the planet, and

easing strain on the whole supply system.

If we all time-shifted our consumption out of the peak

by an average of just 350W (3½ bright old fashioned

light bulbs) the peak would disappear! You don’t even

have to reduce your overall consumption - although

that too is good – just use it at other times.

You can easily do this by delaying the use of

dishwashers, washing machines and tumble dryers,

and by having a time switch on your immersion

heater.



For example, if you usually use your dishwasher at

6pm, delay it until after 8pm, preferably into the

middle of the night if you have a delay timer.

Smart Meters

If you ask people in the electricity industry, many of

them will tell you that the problem will be solved by

smart meters – unfortunately it won’t!

Smart meters in themselves will not switch anything

off, much less work out when to delay consumption

for specific appliances. They will allow for more

complicated time-of-use tariffs. They will penalize us

for using electricity at peak times, but even these will

rely on us to respond by switching things off or

delaying them coming on.

In this guide, I will go through in detail what the

present situation is with regard to electricity supply,

and how you and I can regain some control over how

we use it, for the benefit of all of us, and of the

planet.



THE CURRENT SITUATION

Not only does our electricity consumption vary

wildly throughout the day, the way it is supplied

does as well.

Please bear with me through the graphs that follow –

real time graphs can also be seen in interactive form

on

http://nationalgrid.stephenmorley.org/

It’s an amazingly dynamic site created by a Cambridge

University computer whizz-kid!



Here’s a chart showing the production of electricity

from all major sources on Monday 15th December

2014 – a fairly typical mid-winter weekday:

This chart tells us a lot about what is going on. The

peak production which is the sum of all the different

types was about 51 Gigawatts. The biggest

contributors at the peak were gas (CCGT, which

stands for combined cycle gas turbine) and coal, at

17.43 and 16.81 respectively. The next was nuclear at

8.1, with wind power at 2.92 and others all below

2GW each. Of course it is well after dark at 5pm



in mid-December, so there will have been no solar

photovoltaic electricity.

The next thing to notice is how the different sources

vary through the day.

Nuclear is more or less constant, for two reasons,

firstly it is quite difficult to speed up or slow down a

nuclear reactor in a hurry, and secondly there’s not

much point in doing so, as the fuel cost saving is very

small. The cost of nuclear power is almost all in the

construction and decommissioning, very little in the

fuel.

Wind power bears no relation to demand, because

wind turbines are left to run at the maximum output

the wind allows. There is a bit more wind in winter

than in summer, but not reliably so.

Gas and coal vary with demand. They are the sources

that bear the brunt of daily variation in demand. Gas

in particular can be ramped up and down very fast.

If it were not for our concerns about climate change



and security of supply, gas could easily supply all our

electricity needs.

Now let’s take a look at what happens at the other

end of the day – the minimum or trough

consumption, which happens not surprisingly in the

middle of the night:

This is the chart for 2am on Tuesday 16th

December

2014.

Total production is about 32 gigawatts, just under

two- thirds what it was at the peak. The difference

between peak and trough would be much greater if



big industrial users didn’t manage their consumption

to use more at times of overall low consumption, and

less at other times.

But look at which sources are bearing the brunt of the

change. Not nuclear or wind, which as we have seen

do not vary in their output with demand over the day.

Coal has come down from 16.8 to 12 Gigawatts, a

reduction of 30%, so proportionately less than the

overall reduction of 37%.

Now look at gas. Gas fired production has fallen from

its peak of 17.4 down to only 3GW, a fall of 83%. It is

gas that is overwhelmingly bearing the brunt of

demand variation over the day.

Consider now what would happen were we to

increase wind power by a factor of two, from 4.6 GW

to 9.2 GW at the time of minimum demand. That’s

more than the total gas fired production at that time.

What would need to happen? Could gas-fired

production be reduced to zero? Could coal fired

power be reduced sufficiently quickly to balance the



supply? In practice, it is likely that even more of the

demand would be switched to gas throughout the

day, and gas would have an even more extreme range

to cover.

Some people think that would be a good thing,

because gas is much less carbon-intensive than coal.

But it would also mean that more gas-fired stations

would be needed but providing less electricity each,

thus making gas-powered electricity more expensive.

There are some inconvenient truths here: more wind

power means more expensive gas power, and PV

makes no contribution at all to peak demand. They

are still a good thing if you want to reduce carbon,

but they have their own limitations.

WHAT ARE WE CURRENTLY DOING ABOUT IT?

There are some projects underway looking at ways to

influence demand in peoples’ homes. They are funded

by the Low Carbon Network Fund, overseen by



OFGEM, and electricity distribution network

operators (DNO’s) are obliged to take part in these

projects.

The projects are looking at both technical and

behavioural resolutions of the issue of demand

management. However, they are all in the context of

the introduction of smart meters over the next seven

or so years.

Meeting peak demand reliably is a major issue for the

Government. No one really knows what demand will

be in ten, twenty or thirty years’ time, or how it will

be supplied. So we find ourselves in a situation where

we are forced to pay whatever it takes to build a very

large new nuclear power station, Hinkley C.

This station on the Somerset coast will produce 3.2

Gigawatts, more than half the current peak electricity

demand of South West England. It will do so at a cost

of between 16 and 24 billion pounds, depending on

whether you believe EDF or the EU, who came up

with the higher figure. That’s £8000 per kilowatt,

about what is needed for each household in the



region. Ouch. Even spread over thirty years, that’s

£266 per year for each household on top of our bills.

Hinkley is probably a done deal – they are already at

work on the site. But how many more Hinkleys will it

take to satisfy our demand for electricity?

Some people put their faith in more gas-fired power

stations. These have the advantage of being much

cheaper to build, very flexible in their output, and

lower carbon than coal or oil. But how long will the

gas last at reasonable prices? How much carbon will

they put into the air? If we have more wind and other

renewable power, how expensive will it be for gas to

fill in the unpredictable shortfalls in supply when the

wind doesn’t blow and the sun doesn’t shine, or when

the tides are wrong or the waves are small?

And what about those smart meters? Will they solve

our problems? The short answer is no. Smart meters

in themselves do not switch anything off. They simply

provide information on how much we are using and

when we are using it. They provide the basis for the



introduction of time-of-use tariffs, which will

eventually motivate some of us to use less electricity

at peak times, by charging us a lot more for it, and

less at other times. If the introduction of time-of-use

tariffs is voluntary, then those - usually poorer-

consumers, who don’t choose to go over to them, will

just be charged more for their electricity all the time.

Another concern with smart meters is their cost. To fit

them to the 26 million domestic households will cost

about £350 each which is nearly £10 billion, and

there is much debate over what the net resulting

savings will be. The House of Commons Public

Accounts Committee, (chaired by Margaret Hodge, a

left-wing Labour MP not previously associated with

penny-pinching attitudes) cast doubt on the idea of a

mass rollout of smart meters, citing not only their

cost, but also their technical obsolescence in the face

of app-controlled smart plugs and other fast-moving

developments in the sector.



The timescale for all of this to happen is also very long

and may well be getting longer. 2021 is currently

predicted for the completion of the smart meter

rollout. As yet there is no indication of when time-of-

use tariffs may be implemented, but they require

smart meters before they can be brought in.

There is an underlying theme to all of these issues –

cost! It is expensive to deliver top-down solutions to

providing reliable electricity whenever it is wanted.

Does the solution lie elsewhere?



AN ANSWER THAT WORKS

It is unusual for there to be a simple, cheap and easy

solution to a seemingly intractable national problem.

This is an exception.

Let’s start from the other end of the problem – us –

you and I -the consumers of electricity.

If we all time-shifted 14% of our peak consumption,

about 350 watts per household, away from the period

between 3-8pm on winter weekdays, the peak would

disappear and we would need seven fewer large

(1GW) power stations. That’s seven coal or gas-fired

power stations we could close without the need for

replacement.

We can do this with minimal loss of convenience by

delaying the use of dishwashers, washing machines

and tumble driers into the middle of the night, and by

fitting time switches to our immersion heaters, for

those who have them.



If instead of consuming electricity at peak times we

did so at trough times, it would also enable much

higher levels of renewable electricity to be fed into

the grid.

One possible response to this message is – other

people won’t do it, so what difference will it make if I

do so?

But we are very remarkable people.

In 1984 we gave £150 million to Live Aid for famine

relief in Africa.

Our foreign aid budget is £11 billion. Most of us

approve of it, otherwise politicians wouldn’t do it.

And - perhaps the most relevant- we now recycle

most of our rubbish, sorting it into categories, all for

no direct reward.

Why? Because we know it is the right thing to do.

We know that our own personal contribution to the

effort is statistically insignificant. But we do it anyway



– because we know that if we all do it, it does make a

difference. A difference that benefits us all.

There are many other examples of altruistic collective

action which we now take for granted. They all

started out as a new idea, which caught on.

If we all do it, we will save up to £35 billion, over

£1000 per household in generation capacity costs.

The carbon emissions of our electricity will fall

substantially.

The strains on our creaking distribution structure will

be eased, thus reducing the risk of power cuts.

Taking responsibility for our electricity consumption is

a remarkably easy opportunity to make a difference.

Please do it - and tell your friends you are doing it.



IS TIME-SHIFTING THE ONLY ANSWER?

Most of the people I talk to about time-shifting have

their own, different solution to reducing carbon and

improving the efficiency of our electricity

consumption.

In one sense, they are all correct. There are myriad

ways of generating, saving, and storing electricity, and

I will go through some of them to explain why time-

shifting is the overarching enabler to any attempt to

reduce electricity’s financial and environmental costs.

Intermittent Renewables

This encompasses virtually all renewable forms of

electricity with the exception of biomass and

hydropower, (both of which I assert are of limited

application in UK- we just don’t have enough trees or

mountains). In particular, wind, solar, tidal and wave

power are intermittent, that is they cannot be called

upon (dispatched in the technical jargon) consistently

at peak times. Some argue that over a wide range of

technologies and a wide range of locations, there will



be some degree of reliability. With a worldwide

distribution system, it may be possible, but that could

be a very long way off if at all.

However, with time-shifting the problem is

transcended. The more time-shifting we are prepared

to do, the more intermittent renewable electricity

becomes possible. Without it, the UK would struggle

to have 20% renewable electricity, because there

would need to be no danger of renewable generation

exceeding the capacity of the grid to absorb it at

trough times. Summer troughs can be as low as 20GW

which puts a technical limit to renewables at that

time of about 10GW. The National Grid has

documented this eloquently on their website.

Nuclear Power

Nuclear power, though expensive and potentially

dangerous, is reliable in the sense that it can be called

upon to deliver power at specific times. However it is

not easy to speed up and slow down reactors in a

hurry, and in any case the costs are nearly all in the



construction and decommissioning, not in the fuel

used in generating the electricity. If nuclear reactors

continue to be used to generate continuously through

the day, then it is advantageous to time-shift demand

away from peaks and into troughs to make best use

of the power.

Fossil fuels

There is a desire to minimize the use of gas and

particularly coal-fired power stations. However, the

economics of these depends on their load factor - that

is the proportion of the time they are running. British

Gas (Centrica) has been arguing for some time that

increasing the amount of renewable electricity is

reducing the load factor of gas power stations, thus

increasing the cost of production. We as taxpayers

will be asked to pick up the bill for the extra costs of

gas-fired power. Time-shifting would redress this

balance, allowing for fewer gas-fired stations

operating at a higher load factor, thus reducing both

costs per unit and the amount of gas needed to meet

the lower peaks.



Electricity Storage

Storage costs money. At the moment the only cost-

effective form of electricity storage on a Gigawatt

scale is pumped storage, that is pumping water

between two reservoirs at different heights, and

generating electricity by allowing it to run back down

again through a hydro-electric generator. There are

inevitably losses in this process, in addition to the

capital costs of the system. With time-shifting, less

use of pumped storage will be needed.

Other forms of storage, for example batteries,

flywheels, compressed gas, are more expensive.

Time-shifting is cheaper than storage, usually by a

factor of ten or more. In fact, time-shifting can be

regarded as a form of storage- of demand rather than

of supply. There are cases where storage is

nonetheless essential, for example in uninterruptible

power supplies (UPS) for vital computer systems such

as in banks or hospitals. If you have a laptop



computer, you have a UPS! Time-shifting will enable

these stores to be smaller and less expensive.

New Nuclear

There are designs currently being developed for

smaller, possibly less dangerous and cheaper nuclear

power stations, for example Thorium reactors. These

could be as small as a lorry container, easily

transportable to remote sites, and back to central

depots for refueling, perhaps once every ten or

twenty years. The potential cheapness and

convenience of this sort of reactor does not allow it to

escape from the same economic factors as a large

reactor - that is, they are much cheaper to run

continuously than to vary with demand. So once

again, time-shifting will improve their cost-

effectiveness.

In summary, all electricity technologies, old and new,

work much better if demand is managed to minimize

peaks and troughs.



SMART DEVICES

I have already explained how we can easily and

conveniently time-shift our electricity consumption

using very simple time-switches and the delay timers

found on modern appliances.

So why are there a plethora of devices available to do

what appears to be easy to do anyway?

Over the last few years, we have been trying to solve

the demand/supply mismatch problem technically.

That is, to come up with increasingly sophisticated

devices and software to do what we can already do

without them. We have put the expensive technical-

fix solution ahead of the cheap behavioural- change

solution.

An additional problem with this approach, as well as

the cost, is that you need the behavioural change

anyway. However many fancy devices we have, we

still have to change to use them – the question here is

whether we choose to do it, or have it forced on us.

Compulsion is likely to be counterproductive.



For example there is already a resistance movement

to smart meters, which are sometimes seen as

Orwellian in nature, intruding into peoples’ homes to

find out more about how they live their lives. Others

object to the idea of increased levels of radiation

from the necessary signal transmission from smart

meters. Whilst I am personally relaxed about these

issues, they are real for many people.

Don’t get me wrong, I don’t have an issue with using

new smart devices, quite the contrary. It’s just that

they are no substitute for individual action, just a tool

for implementation, to be used when the cost is

justified by the additional savings or convenience.

Let’s take a look at some of the devices coming on to

the market.

Smartphone app-controlled switches

Devices such as the Belkin Wemo switch work

through your Wi-Fi broadband system. Using a

smartphone, you can tell it to switch on and off at

will, from anywhere in the world.



You can also program it to come on and off at specific

times. For the purposes of simple time-shifting to

avoid the existing peak, it’s a sledgehammer to crack

a nut!

It would however be very useful if you decided to

delegate the time shifting of appliances to someone

else. Why would you want to do that? It may be that

your electricity distributor has local stress points

where it is useful to reduce the load for a period. For

example, in remoter rural areas off the mains gas

supply, many people still use electric storage heaters.

It would be useful for the electricity distributor to

have more control over exactly when they go on and

off, to avoid a sudden surge at midnight. They might

even want to switch them on during the day if there is

a surge in renewable power. Eventually they will be

able to reward you for offering the opportunity to do

just this. But not until you have a smart meter!



Appliances with built-in internet connections (the

Internet of Things, or IOT)

Why would you want a dishwasher with an internet

connection? It’s another way for the distributor to

manage demand on your behalf just as the app-

controlled switch does. It’s something we may need if

gas-fired power stations are phased out and no longer

provide fast-changing supply in response to our fast-

changing demand.

It’s unnecessary, though, to use such devices when

we time-shift away from the existing peak today.

Immersion heater diverters

For those of us with solar PV systems, devices such as

the Immersun or Optiplug divert electricity to the

immersion heater when there is a surplus of solar

electricity. This is a useful form of personal demand

management, which maximises the benefit PV owners

can get from their electricity tariff.

In future it could be useful for all of us to do this over

a local area, when the overall level of PV is high.



At these times there is a difficulty in distributing the

surplus away to other areas if it coincides with low

demand and bright sunshine. Then, everyone will

benefit, not just the PV owners.

So there are many ways in which we can refine or

delegate control over our demand, but generally they

are not dealing effectively with the peak demand

issue we face today.

We come back to the simple use of delay timers and

time switches to effect immediate change.



THE NEXT STEPS

• Tell your friends you are time-shifting your use of

electricity. Word of mouth is very effective, as

Alex Laskey of OPower tells us in his online video

(google Alex Laskey).

• Let community energy groups know about it.

They are also good at spreading messages

amongst motivated and environmentally

responsible early adopters

• Lobby for community groups to get rewarded for

making it happen. A Senior Partner of OFGEM has

already suggested that this is on the cards.

(Renewable Futures Conference, Bath, November

2014.)



CONCLUSION

We can save ourselves a lot of time, money and

effort, avoid carbon pollution, and take control of our

use of electricity by simple time-shifting of demand.

We have demonstrated that we are not irresponsible

or stupid by our altruistic recycling habits, so there is

no validity in the argument that such behavioural

change is too difficult for us.

Good luck and happy time-shifting!

References

http://www.ted.com/talks/alex_laskey_how_behavioral_science

_can_lower_your_energy_bill?language=en

http://nationalgrid.stephenmorley.org/

https://www.gov.uk/government/uploads/system/uploads/attachment_dat

a/file/66198/National_Grid_-_solar_PV_briefing_note.pdf



Tom Langdon-Davies is an independent commentator

on environmental and organisational questions.

He is also Chairman of ET Index Ltd, an environmental

tracking company in Canary Wharf, London, and

author of How to be an Effective Chairman, available

now on Amazon Kindle and from May 2015 in hard

copy.

http://theintelligentplug.com

[email protected]