Arch Building Systems II (2000/2001) Energy and Environmental Systems for Green Buildings Lecture 07 - Renewable Energy Systems
Contents zBasic Concepts zActive Solar zPhotovoltaics zWind Energy zOther Renewables RE
* Artwork by Allison Allen Phillips, Grade 6, Thurston Middle School, Laguna Beach, California
Basic Concepts zCommon renewables ysolar ywind ybiomass yenergy from waste ygeothermal yhydro ywave and tidal yocean thermal
Basic Concepts zRenewables for buildings ysolar energy xpassive (low energy architecture) xactive (solar thermal) xphotovoltaics yother renewables xwind (using buildings to harvest wind energy) xgeothermal (e.g. hot springs) xsmall hydros (e.g. water wheels) yhybrid systems (e.g. PV + wind + diesel)
Passive solar (e.g. skylight) Active solar (solar hot water) Photovoltaics Integration of solar energy systems in buildings
Active Solar zAlso called ‘solar thermal’ zCommon applications ysolar hot water (domestic or non-domestic) yswimming pool heating yspace heating or air preheating ysolar air-conditioning xusing absorption or desiccant cooling system yelectricity generation xusing steam plant and concentrator
Simplified schematic of a solar hot water system
Design of solar collectors
Basic structure of a flat-plate solar collector
Heat transfer processes at a flat-plate solar collector
Photovoltaics zPhotovoltaics (PV) yconvert sunlight into direct current electricity using a semi-conductor device xmaterials: crystalline and amorphous silicon (sand) yapplications: xconsumer products (e.g. calculator, radio) xremote-site (e.g. remote telecom and weather station) xcentral power generation xbuilding-integrated systems
Principles of photovoltaic cells
PV cells, modules and arrays
PV installations in buildings Array Tilt angle = latitude ( o ) + 15 o * Locate array in an unshaded area facing the equator (a) Roof (horizontal) (b) Facades (vertical)
Efficiency and price of PV modules Current price = US$4-5/Watt (panel only)
Wind Energy zDesign factors ylocation: inland or off-shore xe.g. wind farm ywind turbines: horizontal or vertical axis ywind speed xcut-in = 3-5 m/s; shut-down = m/s zEnvironmental impact ye.g. noise, visual, interference
Off-shore wind turbines Wind turbines on inland or islands Vertical axis wind turbines
Project Zed - London Dutch pavilion, EXPO 2000 Hannover
Power curve and noise level of wind turbines Cut- in Shut- down
Other Renewables zBiomass yusing wood, agricultural residues as a fuel yenergy from waste incineration or digestion ylandfil gas, biogas and biofuel zSmall hydro yin mountain areas or rivers zGeothermal - earth heat zWave, tidal, ocean thermal energy
Use of landfil gas for electricity and heat
Small hydro system (example)
Other Renewables zDesign strategy yassessment of the potential xsolar, wind, hydro, geothermal, etc xeither on the site, or off (near) the site yeconomic analysis xinvestment/finance required xenergy generated, running costs yintegration xwith the building xamong the systems