Monday 27 April 2009

Defence. Investment Appraisal Board (IAB)

(extract from 2001 document - link above)
The Investment Appraisal Board is responsible for central scrutiny of equipment requirements, major capital works and Information Technology projects. It makes recommendations to Ministers on the procurement of major defence equipment.

The IAB is
  • chaired by the Chief Scientific Adviser (MoD CSA) and includes
  • the Vice Chief of the Defence Staff (VCDS),
  • 2nd Permanent Secretary (2PS),
  • Chief of Defence Procurement (CDP) and
  • Chief of Defence Logistics (CDS), reflecting the key Departmental stakeholders.

Professor Mark Welland FRS FREng busy in his new role as MOD Chief Scientific Adviser.

Sunday 26 April 2009

Google Powermeter

What Google is Doing

Google PowerMeter, now in prototype, will receive information from utility smart meters and energy management devices and provide anyone who signs up access to her home electricity consumption right on her iGoogle homepage. The graph below shows how someone could use this information to figure out how much energy is used by different household activites.

PowerMeter annotated graph
Get better information about how you use energy and what you can do to be more efficient.
Reduce your energy bills and carbon footprint by making smart decisions about your energy use.
Strike up a little friendly competition to see how your energy consumption compares to your friends and neighbors.

The Conservatives' plan for a 'Green technology recovery'

George Osborne has set out a series of measures that could be introduced in next week’s Budget and would bring about a green technology revolution in Britain.
The Shadow Chancellor stressed, “The Budget is not just an opportunity to help people now; it’s also a chance to chart a new course for the future.”

And he outlined a series of policies to “kick-start a green recovery” built on new technologies developed and manufactured in Britain:
  • A £6,500 energy efficient entitlement for every home in Britain
  • Funding at least three carbon capture and storage pilots (2)
  • The introduction of feed-in tariffs (4) and smart meters (3) to encourage homes to microgenerate using wind turbines and solar power
  • A national recharging network for electric vehicles (5)
  • Beginning work on a new high-speed rail network (6)
  • Investing in the creation of an electricity internet (7)
  • Providing government loan guarantees to companies investing in green technologies
  • Creating the world’s first environmental trading market
  • Introducing a network of Marine Energy Parks
  • Building an offshore DC cable network (10)
George stressed their plan “could transform Britain”: “It would unleash £30 billion of new private sector investment, without adding a penny to the national debt. It would lay the path to a greener future. And it would help build a future economy where we save and invest for tomorrow instead of borrow and spend for today.”

Saturday 25 April 2009

Tidal Power - David JC MacKay; the beauties of tide

extracted from
Sustainable Energy - without the hot air

Beauties of tide

Totting everything up, the barrage, the lagoons, and the tidal stream farms could deliver something like 11 kWh/d per person (figure 14.10).

Tide power has never been used on an industrial scale in Britain, so it’s hard to know what economic and technical challenges will be raised as we build and maintain tide-turbines – corrosion, silt accumulation, entanglement with flotsam? But here are seven reasons for being excited about tidal power in the British Isles.
1. Tidal power is completely predictable; unlike wind and sun, tidal power is a renewable on which one could depend; it works day and night all year round; using tidal lagoons, energy can be stored so that power can be delivered on demand.

2. Successive high and low tides take about 12 hours to progress around the British Isles, so the strongest currents off Anglesey, Islay, Orkney and Dover occur at different times from each other; thus, together, a collection of tide farms could produce a more constant contribution to the electrical grid than one tide farm, albeit a contribution that wanders up and down with the phase of the moon.
3. Tidal power will last for millions of years.
4. It doesn’t require high-cost hardware, in contrast to solar photovoltaic power.
5. Moreover, because the power density of a typical tidal flow is greater than the power density of a typical wind, a 1 MW tide turbine is smaller in size than a 1 MW wind turbine; perhaps tide turbines could therefore be cheaper than wind turbines.
6. Life below the waves is peaceful; there is no such thing as a freak tidal storm; so, unlike wind turbines, which require costly engineering to withstand rare windstorms, underwater tide turbines will not require big safety factors in their design.
7. Humans mostly live on the land, and they can’t see under the sea, so objections to the visual impact of tide turbines should be less strong than the objections to wind turbines.


Tidal power, while clean and green, should not be called renewable. Extracting power from the tides slows down the earth’s rotation. We definitely can’t use tidal power long-term.

False. The natural tides already slow down the earth’s rotation. The natural rotational energy loss is roughly 3 TW (Shepherd, 2003). Thanks to natural tidal friction, each century, the day gets longer by 2.3 milliseconds.
Many tidal energy extraction systems are just extracting energy that would have been lost anyway in friction. But even if we doubled the power extracted from the earth–moon system, tidal energy would still last more than a billion years.

Notes and further reading

page no.
82The power of an artificial tide-pool. The power per unit area of a tide-pool is derived in Chapter G, p311.

Britain is already supplied with a natural tide-pool . . . known as the North Sea. I should not give the impression that the North Sea fills and empties just like a tide-pool on the English coast. The flows in the North Sea are more complex because the time taken for a bump in water level to propagate across the Sea is similar to the time between tides. Nevertheless, there are whopping tidal currents in and out of the North Sea, and within it too.

83The total incoming power of lunar tidal waves crossing these lines has been measured to be 100 kWh per day per person. Source: Cartwright et al. (1980). For readers who like back-of-envelope models, Chapter G shows how to estimate this power from first principles.

84La Rance generated 16 TWh over 30 years. That’s an average power of 60 MW. (Its peak power is 240 MW.) The tidal range is up to 13.5 m; the impounded area is 22 km2; the barrage 750 m long. Average power density: 2.7 W/m2. Source: [6xrm5q].

85The engineers’ reports on the Severn barrage...say 17 TWh/year. (Taylor, 2002b). This (2 GW) corresponds to 5% of current UK total electricity consumption, on average.

86Power per unit area of tidal lagoons could be 4.5 W/m2. MacKay (2007a).

Dartford Crossing Study April 2009

Interesting study including analysis of current supply limitations, nature of demand and future options to meet anticipated demand.

You might have thought from reading the report that additional capacity is required sooner than the Forth Replacement Crossing. This is even more relevant in light of the fact that this is a strategically important crossing with v little in the way of a contingency options in the event of something unforseen happening (not mentioned in the report. 

Sustainable Energy - without the hot air


Dedication Preface (p.viii) (p.ix)

10-page synopsis: (pdf)

I Numbers, not adjectives [pdf]
1 Motivations [html]
2 The balance sheet [html]
3 Cars [html]
4 Wind [html]
5 Planes [html]
6 Solar [html]
7 Heating and cooling
8 Hydroelectricity [html]
9 Light [html]
10 Offshore wind [html]
11 Gadgets [html]
12 Wave [html]
13 Food and farming [html]
14 Tide [html]
15 Stuff [html]
16 Geothermal [html]
17 Public services [html]
18 Can we live on renewables?
II Making a difference [pdf]
19 Every BIG helps [html]
20 Better transport [html]
21 Smarter heating [html]
22 Efficient electricity use
23 Sustainable fossil fuels?
24 Nuclear?
25 Living on other countries' renewables?
26 Fluctuations and storage [html]
27 Five energy plans for Britain [html]
28 Putting costs in perspective [html]
29 What to do now [html]
30 Energy plans for Europe, America, and the World
31 The last thing we should talk about [html]
32 Saying yes [html]
IIITechnical chapters
A Cars II
B Wind II
C Planes II
D Solar II
E Heating II
F Waves II
G Tide II
H Stuff II
IVUseful data
I Quick reference
J Populations and areas
K UK energy history