Outline Sustainable Energy Options for the Civic 3 building.
Key/ Wind turbine / Wind turbines come in many shapes and sizes ranging from small turbines with blade diameters of less than a meter which produce a few watts of electricity to large turbines with blades of up to 100m or more in diameter which produce several MW of electricity
/ Photovoltaic systems / Photovoltaic systems convert the suns energy directly to electricity. The systems are usually mounted on the top of roofs but can also be integrated into roofs or into windows or other building structures.
/ Solar hot water collector / Solar hot water collectors convert the suns energy into heat. The heat generated is usually used to heat hot water in a tank which can then be used to help meet hot water requirements for a building.
B. Civic 3 Building
Figure 4 Aerial photograph showing the Civic 3 building and the potential location of renewable energy options on the building
Energy demand for the site
The Energy data for the Civic 3 is shown in . The following headline issues are apparent for the site:
- Floor Area: 5433.0 square metres
- No of persons: 347
- Building occupancy: 249 hrs per month
- The centre used 435,949 units (kWh) of electricity which cost the centre 21,377.
- The centre used 599,059 units gas which cost the centre 7,457.
- Gas use is lowest in the summer months (averaging 14,034 kWh/month between June and September)
- Gas use is much higher in the non-summer months averaging approximately 67,865 kW/month from October to May and peaking at around 98,000 kWh/month in January.
Figure 5 Energy Data for Civic 3 from April 2002 to March 2003.
Outline energy options for the site
B / Civic 3 building
B1 / / Technology: Building integrated wind turbines installed on the top of the two lift shafts which run each side of the building.
Rating (kW): Up to 12 kW for No. 2 x 6kW turbines Actual acceptable size of turbines will depend on structural studies of the roof structure and visual impression (see artists impression right).
Output (kWh/year): up to 31,537 kWh/year electrical output.
% of site requirements:7.2%
CO2 saving:13.6 tonnes/year
Indicative costs: For the system above, indicative costs for turbine, balance of system and installation would be £15k/system, total cost of £30k
Site integration issues: Few building integrated systems are in existence so little is known of the effects of wind turbines on building structures in terms of vibration. Therefore a structural study would need to be undertaken to confirm that the suggested locations will be capable of taking the loads
Timescale for implementation: Dependent on planning permission and structural report on building.
Additional info requirements: Structural report on areas of roof where integration of systems could occur. View on planning permission timescales. /
B2.1 / / Technology: Photovoltaic cells mounted on elevated frames and installed on the flat roof of the 3 storey Civic 3 building. The estimated total roof area for Civic 1 is 1400 m2. Due to shading and access requirement we assume 25% of the roof area is available for PV installation. We also assume that the PV cells are elevated by 30 to achieve greater energy capture. On this basis we estimate around 350 m2 of roof area would be available for PV installation. With this roof area and elevation around 400 m2 of PV panels could be installed
Rating (kW): 50kWp (with 30 elevation)
Output (kWh/year): 37,500 kWh/year
% of site requirements: 8.6 %
CO2 saving: 16.1 tonnes/year
Indicative costs: £250k
Site integration issues: Mounting units would need to be securely attached to roof battons and structural integrity of roof would need to be checked.
Timescale for implementation. Would depend on planning and structural study of roof. Tendering for systems should be relatively rapid, with procurement potentially fitting into ZEN/SunCities timeframes. Installation again should be relatively rapid if access to roof can be assured.
Additional info requirements: structural studies of roof, planning permission, location of main electrical systems for building. /
B2.2 / / Technology: A small PV system mounted on the entrance to the Civic 3 building. This site would be good for raising the profile of PV within Kirklees. We would recommend the installation of a transparent canopy above the existing double doors (an artists impression is shown opposite). The canopy would provide shading and would be south facing giving it the best chance of generating electricity. The total canopy area would be about 2 m. The canopy could be used to charge a battery for running an interactive display which would show information about other renewable energy systems on the site.
Rating (kW): up to 0.25 kW
Output (kWh/year): 150 kWh/year
% of site requirements: negligible
CO2 saving: up to 65kg/year
Indicative costs: up to £2,000 with display, fixings and battery.
Site integration issues: The PV canopy would not be connected to the grid but would charge a battery for running an interactive display about the other renewable energy measures on site. The main issue would be aesthetic integration with the site.
Timescale for implementation: The canopy should be tendered with the other pieces of work and provided architectural integration can be agreed upon the installation of this system should be completed in the ZEN/Suncities timescales.
Additional info requirements: Would need to agree the detail of the installation with council architects. /
B3 / / Technology: Solar collectors used to preheat water for hot water provision. The following calculations are based upon a typical evacuated tube solar collector. Use of the collectors in this instance will require the installation of a pre-heat tank. The sites baseload gas requirements are about 14,000 kWh/month. If we assume that this is for hot water alone then the annual gas requirement for hot water use will be about 168 kWh/year. Typically an evacuated tube collector will be able to deliver 60% of this requirement, or 101,000 kWh/year. The flat plate collectors will typically produce 600 kWh/m2 of collector area. So the total collector required would be 168m3. Each m3 of evacuated tube collector area typically requires 60 litres of preheat storage area. So the total preheat tank area would be 14.4 m3. An estimated 192 m2 of roof area is available (see assumptions above) and with a 40 elevation on the panels a total panel area of up to 250m2 could be installed. Therefore the maximum sized system would fit on the existing roof.
Rating (kW): (NA)
Output (kWh/year): 144,000 kWh/year
% of site requirements: 60% of hot water, 19% of all gas consumption
CO2 saving: 27.4 tonnes/year
Indicative costs: £160k
Site integration issues: Space would need to be made available for the installation of a hot water tank, and some integration with existing systems would be needed. Mounting frames would need to be installed on the roof.
Timescale for implementation: Dependent on planning permission, structural study on roof, tendering and detailed design of systems.
Additional info requirements: structural study of roof, detailed plans of boiler plant, and details of system controls, likely planning timescales /