4 research outputs found
Thoday Building - NW facing office
<p>Temperature and humidity measurements in an office on the 1st floor of Adeilad Thoday Building. The office has a NW facing external wall and windows. Times are GMT.</p
Average consumption home power logging
<p>These data show power and energy values every 10 seconds over a 9 day period for an 'average consumption' household in North Wales. The data start at midnight on a Friday and end at midnight on the Sunday of the following weekend.</p
How warm is warm enough - graph data
<p>These data were used to create the graph of indoor home temperatures over February and March 2014, as used in the 'How warm is warm enough?' case study on the WISE Network website (http://www.wisenetwork.org/how-warm-is-warm-enough/). Times are GMT.</p
Comparative environmental footprints of lettuce supplied by hydroponic controlled-environment agriculture and field-based supply chains
Attributional life cycle assessment was applied to determine environmental footprints of lettuce produced across ten supply chain configurations, based on either hydroponic closed-environment agriculture (CEA) with six different electricity sources, or field supply chains involving regional, continental or inter-continental transport. Hydroponic CEA systems use circa 15 kWh of electricity for lighting, cooling, ventilation and pumping per kg of lettuce supplied. Based on typical current national grid electricity generation mixes with significant fossil fuel dependence, this results in large environmental footprints, e.g. up to 17.8 kg CO2 eq. and 33 g N eq. per kg lettuce – compared with 10 kg CO2 eq. and 16 g N eq. per kg lettuce air-freighted across continents. However, hydro?ponic CEA can produce orders of magnitude more produce per m2 .yr and can be integrated into existing buildings (e.g. on roof tops, in basements and disused warehouses, etc). Factoring in the carbon opportunity costs of land use, and meeting electricity requirements exclusively through renewable generation, could result in closed hy?droponic CEA delivering produce with a smaller carbon footprint than most field-based supply chains, at 0.48 kg CO2 eq. per kg lettuce. However, this would only be the case where renewable electricity originates from genuinely additional capacity, and where a land use policy or other mechanisms ensure that modest areas of land spared from horticultural production are used for “nature based solutions” such as afforestation. Hydroponic CEA uses orders of magnitude less direct water than field-based systems, and could help to mitigate water stress and associated soil degradation in arid and semi-arid regions used for horticulture – so long as upstream water stress associated with electricity generation is mitigated. CEA could be one of the least sustainable forms of food production if poorly implemented, and has numerous environmental hotspots. But with careful design and scaling, in appropriate contexts of high demand and low agro-climatic potential for production of horticultural produce, CEA deployment could play a role in sustainable food system transformation, potentially helping to reconnect consumers with (urban) producers. There may be opportunities to link building air handling systems with rooftop or basement CEA requiring inputs of cooling, CO2 and water. </p