Question 1 of 4- Thermo fluids [40 marks]

A flat plate with dimensions 1.5 m long and 2.5 m wide faces the Sun. At a particular time of day, the irradiance from the Sun is 800 W/m². the ambient air temperature is 25^?C, and the wind speed is 4 m/s. The absorptivity of the flat plate surface is 0.85. The convective heat transfer coefficient (W/(m²K)) can be estimated usingh= 5.7 + 3.8uwhereuis the wind speed in m/s.

• Calculate the radiative heat gain (W) of the plate due to the solar
• Calculate the convective heat loss (W) of the plate if its temperature is 40 ^?
• Calculate the radiative heat loss (W) of the plate if its temperature is 40 ^?
• Calculate the net heat transfer (W) to or from the plate if its temperature is 40 ^?
• Discuss how a cover on a flat plate collector generally improves

Question 2 of 4- Solar [180 marks]

Solar farms using photovoltaic technology frequently employ single-axis tracking systems to enable optimum performance throughout the day. At a rudimentary level this optimisation is done by positioning the solar panel so that the angle between the solar beam and surface normal is minimised. Practically, other considerations may be included in a tracking algorithm; such as thermal considerations. To set up the task, you are required to:

• identify a real solar farm which uses single-axis tracking technology;

You cannot select Ouarzazate, Morocco for this problem due to Question 3.

• identify a representative solar panel to investigate, and provide its

For this task, you will be investigating the maximum energy output for a single solar panel in two configurations on your birthday:

1. a fixed solar panel that: is located in the same geographical position as the solar farm you identify; has a surface azimuth angle facing the equator; and has a slope equal to the absolute value of the latitude.
2. the same solar panel mounted on a single-axis tracking For your location and date:

• plot on the one figure: (i) the beam component of irradiance on a horizontal plane; and (ii) the beam-normal component of irradiance.

For the fixed solar panel configuration:

• plot the angle between the solar beam and beam normal;
• plot the maximum power output for this solar panel;
• calculate the maximum energy which can be produced from this solar panel on your date at this

For the single-axis tracking system, you will need to extend your fixed panel analysis to show a greater level of content knowledge and engineering skills. For the tracked system;

• clearly communicate the solar farm location and geometry, including latitude, axis of tracking orientation and surface azimuth angle/s.
• plot the value of beam slope which minimises the angle between the solar beam and surface normal throughout the day;

• HINT:thisanalysislikelyrequirestheuseofanoptimiser/maximum/minimumfinding routineasthetextbookequation8(2nded.) cannotbewrittenas? =f(?, ?, . . . ).
• HINT: theboundsofcos?maynotbe{?1, 1}duetothe
  • use your identified values of ?to plot the value of cos? on this day and comment on if you believe your analysis is correct.
  • plot the maximum power output for this solar panel;
  • calculate the maximum energy which can be produced from this solar panel on your date at this

Finally,

• comment on the performance of the tracked system compared to the fixed panel Would a multi-axis tracking system be advantageous over the single-tracking system for photovoltaic application?
• critique your analysis, including assumptions made, limitations, the confidence you have in your analysis.

Question 3 of 4- Solar [50 marks]

After a tour of Ouarzazate, Morocco, politicians have expressed a desire to replicate the multi- technology solar installation (solar photovoltaic, parabolic trough, solar power tower) in the location you have selected in Question 2. Present a brief discussion paper (maximum one page) which includes:

• the engineering (technical, human, environmental, etc) considerations unique to the two additional solar thermal technologies;
• your opinion on if any or all of the solar thermal installations may be appropriate to your site; and
• the key stakeholders for this location should the expansion be undertaken. Youshould supplement your text with a minimum of one valuable supporting
  
  

Question 4 of 4- Hydro [130 marks]

Hydro Tasmania has initiated the Battery of the Nation (BotN) strategic initiative to investigate and map out future development opportunities for the State of Tasmania to make a bigger contribution to a future National Electricity Market (NEM). The Tarraleah scheme redevelopment pre-feasibility study¹was undertaken through this initiative, with funding support from ARENA under the Advancing Renewables Program.

For this assignment problem you will be using your knowledge of hydro power to: (1) estimate extended specifications for a new power station on the left bank of the Nive River opposite the existing power station; and (2) to reverse engineer specifications for the Pelton turbines currently installed at the Tarraleah power station.

The pre-feasibility design team established basic parameters of a new power station to comprise two Francis turbines with a design flow of 20 m³/s (total 40 m³/s), a net head of 305 m and an installed capacity of?57 MW (total 113 MW).

The Tarraleah power station comprises of six 15 MW nameplate Pelton wheel turbines which produce a total power output of 93.6 MW. The static head at the site is 290 m and the total volumetric flow rate through the six turbines is 42 m³/s. Assuming that the six turbines are identical and have four jets each.

For the new power station in the Nive River,

• determine the efficiency of the Francis turbine which was assumed in the pre-feasibility assessment;
• use an engineering design tool to estimate the rotational speed of the Francis turbine in rpm;
• critique the rotational speed you have estimated in (b) with specific reference to the assumptions which you have made; and
• identify if other types of hydro turbines could be suitable for the net head at the Nive River

For the existing Tarraleah power station,

• identify an appropriate turbine efficiency to use and justify this assumption;
• determine the head loss upstream of the turbine;
• assume a bucket turning angle and calculate the bucket efficiency relative to the ideal case;
• calculate the diameter and velocity of the jets; and
• calculate the average radius of the Pelton

END OF ASSIGNMENT

1https://arena.gov.au/knowledge-bank/repurposing-existing-hydropower-assets-for-the-future-

electricity-market/