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Appendix 1- Materials

1.      Isovent chart (P8 Source 1)

2.      NEG Micon Technical Specifications Example One (Source 5)


3.      A refuse-burning power station (Page 30 Source 16)

Text Box: Source 16
A refuse-burning power station (mechanism similar to that for residues)
1.	The waste arrives by lorry	7.	A transformer produces the power at the correct voltage
2.	The waste is moved into the refuse pit	8.	Gases are emitted from the chimney
3.	A crane feeds the combustor	9.	This unit controls the gas emissions to prevent pollution
4.	Hot gases rise from the burning refuse	10.	Ash falls into the quench pit
5.	The water is heated and the steam piped to the turbine	11.	Conveyor belt
6.	The turbine is driven by the steam	12.	Power lines take the electricity where it is needed
Waste composition
Appendix 2- Correspondence


E-Mail to


To whom it may concern:

I am currently doing an investigation for A-Level Physics, and need to know the sources of all my materials. Could you please tell me the name(s) and position(s) of the author(s) (if there is a few, otherwise the name of the group) of "NEW AND RENEWABLE ENERGY Prospects for the 21st Century", and it's Supporting Analysis, both found at

I have to hand it in fairly soon so a speedy reply would be much appreciated. Many thanks.

Simon … (UK Student)

The Lodge
Botton Village
North Yorkshire
YO21 2NJ
Email Address:
0044 (0)1287 661 201


Reply to the above



The consultation paper was written (in consultation with other Government Departments) and published by the DTI on 30 March 1999. The supporting analysis was prepared and published, at the same time, by the Energy Technology Support Unit for the DTI.

Neil Hornsby





Letter to Nedwind

Simon …




Nedwind b.V.

Remmerden 9


P.O. Box 118

3910 AC Rhenen


To Whom It May Concern:


I am an A-Level Physics student and am currently investigating the potential of wind as an energy resource for the United Kingdom in the future. I would be very grateful for any information on wind energy, particularly physical, mechanical and statistical.


Many thanks,

            Yours Faithfully


                        Simon …


Reply to the above:


Dear Mr. …,

With reference to your letter dated June 7,1999 we inform you as follows.

Since October 1, 1998 we are a subsidiary of NEG Micon.
As they are responsible for the UK market we kindly request you to contact them directly.
Please find below the address:

NEG Micon UK Ltd.
Taywood House, 345 Ruislip Road
United Kingdom
tel; 0044 -1932732500

We trust to have been of service to you with this information,`

With kind regards,
Christine van Leeuwen
Secretary Marketing & Sales


Letter to NEG Micon


Simon …




NEG Micon UK Ltd.
Taywood House, 345 Ruislip Road
United Kingdom

To Whom It May Concern:


I am an A-Level Physics student at Stokesley Sixth Form College

I am currently investigating the potential of wind as an energy resource for the United Kingdom in the future. I am interested in any information on wind energy, particularly physical, technical and statistical.


If you could be of assistance to me, I would be extremely grateful.


Yours Faithfully





Appendix 3- Derivations

(Derivation of Betz’s Law)


Text Box:  Consider a single stream of particles. The mass of particles m passing through a certain point at each moment in time will be given by:

m = v M


Where d = distance between particles, M = mass of each particle and v = velocity of particles.

If we consider the mass of particles flowing through a certain area, like that, which the rotor blades sweep through (as shown above), an area term would have to be added and distance would turn into volume per particle. The equation would become

m = v A M


Where A = area through which the blades sweep and V = volume taken up by each particle, with A being perpendicular to the direction of v. Since the density of air, r, is given by

r = M/V

, the mass of the air passing through the area of the turbine blade shown above can therefore be calculated by

m = r A v

where m= mass per second, r = air density (Kg/m3), A = the area swept through by the rotor and V = velocity of the wind through the turbines. The latter we will assume to be the average wind speed, (V1+V2)/2 (see above diagram), which makes the equation for any length of time t

m = r A t (v1 + v2)/2

Power is given by

Power = energy transferred

     time taken

Energy is given by

Energy transferred = ½ m v2


Power = m D v2  = m (v1 - v2)2

                2 t                2 t

Rearrange and substitute this into the original equation

(m = r A t (v1 + v2)/2) to get

   2 P t       = r  A t (v1 + v2)

(v1 – v2)2      2

Text Box: P= r A (v1 + v2) (v1 - v2) 2



If we go through the same process to find the total power in the undisturbed wind flowing through the same area A, we get the value P0 as

Text Box: P0 = r A v13


We can then calculate the ratio of P to P0 (the power we extract to the power in the undisturbed wind):

Text Box: P/P0 = ½ (1-(v2/v1)2)(1+(v2/v1))

Text Box:


·        Using the equation derived by Betz (Appendix 3), we can plot P/P0 as a function of v2/v1, as shown below. We can see that the function reaches its maximum for v2/v1 = 1/3, and that the maximum value for the power extracted from the wind is 0,59 or 16/27 of the total power in the wind.