Merit
Assignment
1. Context
Garvald is a residential centre,
with charitable status, that provides care, training and education for adults
with learning difficulties. The centre is located on the Garvald House Estate,
five miles from West Linton in the Scottish Borders (Figure 1). The area of garden surrounding Garvald House is subject
to a development project. A central part of this project is the construction of
a sustainable building or Ecobarn(Figure
2). The Ecobarn will:
• primarily be an agricultural building for the storage of farm equipment and produce.
• contain a multi purpose room, which will be the venue for a variety of activities for the residents of Garvald and the local community.
•
not be connected to the electricity grid.
• be supplied with energy by an off-grid wind/solar hybrid energy system.
2. Requirements
• To investigate the specification of energy generation and reserve equipment required within the hybrid energy system proposed for an Ecobarn building.
• The hybrid system is required to meet four criteria:
a) provide a reliable all-year-round energy supply.
b) minimise cost.
c) accommodate any future increases in energy demand.
d) minimise energy wastage.
It is the purpose of this assignment to investigate the feasibility of an off-grid hybrid wind/PV renewable energy system to power the Ecobarn building.
Figure 1: The location of Garvald House, to the South-West of West Linton.
Figure 2: Proposed Ecobarn site (Taken and adapted from Digimap, 2005)
Figure 3: The view from wind turbine site looking
South West down the
3. Definition of problem.
1) Climate
Select ‘Glasgow’ from the climate database.
2) Demand data
Select a demand profile named ‘office_A_electrical’ in the demand database. You should scale down the demand profile to the predefined peak load (around 0.44kW) for the Ecobarn building that you are analysing.
3) Supply options
600W wind turbine manufactured by Proven, 100W poly-crystalline PV panels manufactured by Siemens (tilt angle @40deg, orientation facing south) and battery reserve sizes with the capacity of 215Ah at 12V. Refer to Appendix 1 and 2 for technical information. The detailed number of each energy supply systems is given in the predefined scenarios (see Table 1). Assumption of costs for supply systems: 600 watt wind turbine (1,850 pounds); 100W PV (325 pounds per panel); 215Ah at 12V battery (300 pounds per unit).
4) Do demand/supply matching analysis using Merit in terms of the level of correlation between the supply profile of each combination and the hourly energy demand profile.
Make the results tables (in the format of Table 1) format for their annual and seasonal performance in targeted months (i.e. January for winter season and August for summer season).
Table 1: result table of the demand/supply matching
analysis.
|
Combination |
% Match |
Total Supply (kWh) |
Total Demand (kWh) |
Surplus (kWh) |
Deficit (kWh) |
Capital Cost (£) |
|
WT600 |
|
|
|
|
|
|
|
WT600+4PV |
|
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WT600+8PV |
|
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WT600+16PV |
|
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|
|
|
WT600+4Batt |
|
|
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|
|
WT600+4PV+4Batt |
|
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WT600+8PV+4Batt |
|
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WT600+16PV+4Batt |
|
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WT600+8Batt |
|
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|
WT600+4PV+8Batt |
|
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WT600+8PV+8Batt |
|
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WT600+16PV+8Batt |
|
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WT600+16Batt |
|
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WT600+4PV+16Batt |
|
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WT600+8PV+16Batt |
|
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WT600+16PV+16Batt |
|
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|
5) Examine residual energy graphs produced by Merit to identify systems that would produce energy all-year-round and would meet the key criteria of being able to provide the Ecobarn with a consistent and reliable energy supply.
Those systems that meet the key criteria were then further evaluated in terms of:
a) the level of match rate between demand and supply
b) the capital cost of the system.
c) energy surplus due to excess energy generation.
6) Recommend the hybrid system(s) and discuss the desirability of electricity grid connection.
Appendix 1: WT600
Specification
(Proven Energy, 2005a)
Appendix
2: PV Solar Panel Specification
(Siemens, 2000)
