Sustainable Hotel Design Presentation 3 Supply Analysis Group 5
Previous Presentations • 1st presentation • Site analysis • Site Selection • 2nd presentation • Passive design • Demand reduction
Where We Are Now North 1st level • Site C • Initial Building Design Ground level
Our Aims for This Presentation • Supply analysis • Water • Electricity • Heat • Gas
The Result • 62% less electrical energy than an average hotel • 13% less combustion fuel than an average hotel
Water Storage (Full Capacity)
Water Supply Possible Supply Sources • Stream • Scottish Water • Rainwater collection • Greywater collection
Reclaimed Water • Greywater Storage • Toilet flushing 3 days • Car washing • Rainwater 20 days • Toilet flushing • Car washing • Plant watering • Laundry
Reclaimed Water • Rainwater Yield = Collection Area x Average Annual Rainwater Yield x Run-off coefficient x fractional collector efficiency = 1530m^2 x 2277.8mm x 0.8 x 0.8 = 2,230,422 litres/year = 6,111 litres/day • Greywater Yield = bathroom use in morning x no. of people = 80 litres x 70 = 5,600 litres/day (full capacity)
Reclaimed Water • Total Reclaimed Water = 11,711 litres • 55 wcs • 180 litres storage per wc/day = 9,900 litres
Supply Systems • Power • Wind • Small scale hydro • Photovoltaics • Heat • Ground source heat pumps • Solar thermal collectors • Combined Heat and Power • Biomass
Justifying CHP • Sustainable design- reduced emissions • Matches hotel demand profile well • Efficient + cost effective • Secure and reliable supply
Justifying Biomass • ‘Carbon Neutral’ Process • Can be self sufficient or locally sourced • Lesser transport requirements (compared against fossil fuels) • Encouraged by government and council
Operation/installation Strategies • Integration with other technologies: PV, Hydro, boiler. Hydro GSHP PVT Pool CHP Boilers
Economics • Heat/Power ratio 4:1 • 1.5kg/kWhe • Wood Chip market value £40/tonne • Fuel price = 6.0p/kWhe • O+M = 1.5p/kWhe • Total Price = 7.5p/kWhe
Power Requirements • Electrical Demand- Limiting factor • Power Req. = 55 MWh • Operational period 8000 h/yr • CHP size = 15kWe • Price = £1275/kW • Total = £19 125
Simple Price analysis • Electricity produced = 55 MWh • Value of electricity = £3500 • Heat produced = 220 MWh • Value of heat = £4000 • Savings per annum = £3750 • Cost of CHP = £19125 • Payback period = 5.1 years
Bruce Henry • Renewable supply options for the hotel • Wave and tidal energy • Solar resource • Wind resource • Hydro resource
Wave/Tidal Power • Discount waves and tidal as: • The bay is sheltered, cost for cabling • Expensive • Unreliable • Industry is in its infancy
Comparison of devices • kWh/m2/year Gives an idea of power size ratio • £ per kWh/year Give an idea of instillation cost and payback period
Solar power • Photovoltaic devices • Insolation 2kWh/m²/day (efficiency of 18%) • 130 kWh/m²/year • Approx £900/m2 • £6.16 perkWh/year • 25 years
Wind Resource α = 1/7 Vmean=6.2ms-1 Pmean=279.8W/m2 Pbetz=165.1W/m2 Total available to wind turbines = 1446kWh/m2 per year
Vertical axis wind turbine Rating:6000W Frontal area = 5 x 3m 11,000 kWh per year (733kWh/m2) Cost: £30,000 £2.72 per kWh for year
Ducted Wind Turbine • Size of device with is 1.5m x • 1m • Hence for these devices • (735.3 kWh/m2) • Power coefficients of about • 0.3 have been achieved for • a 0.5 meter diameter. • Cost is approx £800 • £1.08 per kWh/year
Horizontal Axis Wind Turbine 600 Watt wind turbine/generator £1,845 Diameter 2.55mOutput 450kWh/m2 Total 2300kWh – £0.80 per kWh per year 1500 Watt wind turbine/generator £3,655 Diameter 3.5m Output 769kWh/m2 Total 7400kWh- £0.49 per kWh per year 6000 Watt wind turbine/generator £7,765 Diameter 5.5m Output 816kWh/m2 Total 19400kWh- £0.40 per kWh per year 15000 Watt wind turbine/generator £14,900 Diameter 9m Output 762kWh/m2 Total 48500kWh- £0.31 per kWh per year
Micro Hydro • Water 800 times denser than air, • Constant power source • Single nozzle version for heads from 34 metres and power output of 8kW. Flow requirement 40 l/sec • £20K estimated, 70MWh per year available • £0.28 per kWh/year
Summary Micro hydro will be used to meet as much of the supply demand as possible. (70MWh/year) Proven 1500w turbines will make up difference. (14.8MWh/year) Total cost of installation = £27.5K Batteries will be incorporated to store power from the turbines
Solar Thermal Heating • NW Scotland - produce around 300kW.h per m² annually. • Building orientation - little defect on output within 45 degrees of south. Optimum tilt 33 degrees, little defect 15 degrees either way (pitch of roof). • Solar collectors cost from £300-£700 per m². 2-4m² typical domestic system costs around £3000 and delivers around 1000kW.h per year meeting around half hot water demand. • Pumped indirect system would be the most effective to install and would prevent freezing. • Could possibly be used for space heating, water heating and heating the swimming pool.
Solar Thermal Space Heating Solar Thermal Underfloor Heating Seasonal Performance: • Summer around 4kWh/m² (daily average) • Winter around 1kWh/m² (daily average) Space heating requires large collector areas to supply heat in winter when it is needed most. (200-300m² for hotel)
Solar Thermal Water Heating • Used to preheat hot water for CHP, large collector area required to cope with high hot water demand • Collector area required to be larger than half the swimming pool to heat it (would cost around £30k)
Ground Source Heat Pump • A 20kW heat pump would be required to provide 100 000kWh per year • Cost around £12 000 • Provides 1/3 of hotels heating • Ground temperature relatively constant around 11°C (sea temperature varies 5- 14 °C annually). Efficiency drops when temperature drops in winter, when it is needed most.
Ground Source Heat Pump • COP of 3 - needing around 7kW electrical input • Underfloor heating gives a higher COP as it works at a lower temperature (30-35°C) however radiators (50°C )give individual occupant control in bedrooms. • Space available around site to dig a trench to lay horizontal ground arrays (cheaper than a borehole). • GSHP connected to either five 50m closed loop horizontal ground arrays or a 200m trench for a spiral horizontal array.
Heating Supply Conclusions • Solar thermal heating - not cost effective, require large collector areas and expensive capital costs to meet 100 000kWh annual demand. • GSHP – more financially viable for meeting heating demand. Require top up heating from CHP if radiators are to be used, resulting in a lower COP.
Thank You for Listening Any Questions ?