Industrial and Agricultural Applications of Solar Heat

Mankind’s earliest use of solar energy was probably the drying of food crops to aid their preservation. Open sun drying of fruit, vegetables, fish and meats often improved or enhanced particular flavors and textures such that solely because of those attributes many dried products remain in culinary use today, as examples, dried seaweed, sun-dried tomatoes, raisins and dried pistachio nuts. Open sun drying is displaced increasingly by glazed solar dryers that (i) enable equilibrium moisture content to be reached sooner and (ii) avoid losses of the crop to insects and rodents. A further agricultural application, the greenhouse extended the use of solar energy from post-harvest to crop-production. Today greenhouses are ubiquitous with a huge variety of designs providing a wide range of modified climates for plant growth. Solar energy also finds use in agriculture in solar water pumping for irrigation and in the desalination of brackish water. Solar cooking has taken the use of solar energy in the food production chain directly to the end-user. Broader industrial uses of solar energy have also tended to be linked to food and beverage production because the temperatures required can be satisfied readily in many climates by a well-designed solar thermal system. Non-agricultural technologies such as solar furnaces have considerable potential but have had limited practical use to-date. This chapter discusses the attributes, contexts and applications of the full range of industrial and agricultural applications of solar heat

Optimization of PV powered SPD switchable glazing to minimise probability of loss of power supply

Suspended particle device (SPD) glazing is an electrically actuated switchable glazing. It requires alternate current (AC) power supply to switch from opaque to transparent state. To power this glazing using PV device requires inverter. Optimization of AC powered switchable SPD glazing using photovoltaic (PV) device has been evaluated using loss of power supply probability (LPSP). Electrically switchable direct current (DC) powered electrochromic glazing was also considered in this investigation as it doesn\u27t need any inverter to couple with PV. It is concluded that behaviour of these glazings is the dominant factor in performance optimization outweighting than azimuthal orientation and inclination of PV

Corrigendum to “Energy savings across EU domestic building stock by optimizing hydraulic distribution in domestic space heating systems”

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Interior Colour Rendering of Daylight Transmitted Through a Suspended Particle Device Switchable Glazing

The colour rendering index (CRI) and correlated colour temperature (CCT) of daylight change upon transmission through a variable transmittance suspended particle device (SPD) switchable glazing. The luminous transmittance of SPD glazing was found to vary from 0.02 to 0.55 in opaque and transparent state respectively. Below 0.14 transmittance, the CRI for a particular SPD glazing was less than 80. No strong correlation was found between CCT and CRI. The CRI of SPD glazing in a transparent state was similar to double panes glazing for SPD glazing transmittance greater than 0.24

A Generalisable Bottom-up Methodology for Deriving a Residential Stock Model From Large Empirical Databases

Specifying representative reference buildings as a prerequisite for calculating cost-optimal energy performance requirements for buildings and building elements. Appropriate characterisation is prerequisite data for an overall national building energy consumption model to produce valid outcomes. Energy Performance Certificates (EPCs) are issued in the EU, for dwellings whenever they are constructed, sold or leased. Where acquiring data for an EPC would be prohibitively costly, nationally applicable default-values are employed for the building envelope thermal transmittance coefficients. Significant levels of retrofits led to the default-values used now being higher than is typical in reality, leading to characterisations of reference dwellings based on these defaults lacking validity. A methodology is presented for the derivation of simplified default-free inputs to a bottom-up residential cost-optimality energy consumption model from an EPC dataset. 35 reference dwellings (RD’s) are employed to appropriately characterise 406,918 dwellings averaging one RD per 11,626 dwellings. The strong association of dwelling age and energy efficiency has been found to be diminishing as retrofits have been carried out. A view that the majority of dwellings in Ireland are thermally sub-standard may no longer be true

A Generalisable Bottom-up Methodology for Deriving a Residential Stock Model From Large Empirical Databases.

Average reference dwellings representing a predominant housing typology are defined in this work. Specifying such reference buildings is a prerequisite for (i) calculating cost-optimal energy performance requirements for buildings and building elements and (ii) ensuring valid calculations of national building energy consumption. In the EU, an Energy Performance Certificate (EPC) rating is an assessment of the energy consumption of a dwelling. The use of inappropriate default-values for the building envelope thermal transmittance coefficients (U-values) and standardised thermal bridging transmittance coefficients (Y-values) in the production of EPCs leads to an over-estimation of potential energy savings from interventions in the existing dwelling stock

Energy Performance Certification: Misassessment Due to Assuming Default Heat Losses

Energy Performance Certificates (EPCs) are issued when dwellings are constructed, sold or leased in the EU. Where the cost of obtaining the required data is prohibitive, EPC assessors use nationally applicable default-values. To ensure that dwellings are not assigned a wrongly-higher EPC rating, a standardised thermal bridging transmittance coefficient (Y-value) is typically adopted for all existing dwellings while worst-case overall heat loss coefficients (U-values) are used. Default U-values are applied to a specific building element type (roof, wall, floor etc.) based on building codes and regulations applicable at time of construction. Due to significant building fabric upgrades, default U-values are considerably higher than real U-values. This constitutes a systematic \u27default effect\u27 error typical of large national EPC datasets. For the dataset considered thermal default use overestimates potential primary energy savings from upgrading by 22% in dwellings constructed when thermal building regulation applied and by 70% in dwellings built before thermal building regulations. A methodology has been developed that derives from an EPC dataset, a method for calculating a realistic energy-improvement payback when use of pessimistic default U-values is unavoidable

Thermal Refurbishment Status of the Irish Housing Stock

Energy Performance Certificates (EPCs) are issued for buildings constructed, sold or leased across the EU. Using a generalizable methodology this work exploits Ireland’s EPC national dwelling stock database to determine the thermal refurbishment status of Ireland’s housing stock. It is estimated in 2014 that; i) 58% of walls were insulated at a mean overall heat loss coefficient or U-value of 0.66 W/m 2 K, ii) 67% of roofs were insulated at a mean U-value 0.37 W/m 2 K, iii) 97% of windows were double-glazed, and iv) 53% of floors were insulated to a mean U-value of 0.59 W/m 2 K. The (i) extent of thermal refurbishments and (ii) high degree of energy-efficiency improvements in Ireland contribute significantly to household energy usage per square metre being 9% below the EU 27 average in 2010, and the average energy efficiency of Irish housing having improved by over 34% between 1995 and 2011 (2.5% per annum). The distinction between the thermal efficiency of pre-thermal building regulation and post-thermal building regulation dwellings, whilst still valid, is lessening. A strong association between dwelling age and energy efficiency often-made is diminishing as retrofits continue to be carried out. The long-held view that the majority of Irish dwellings are thermally sub-standard is no longer valid

Durability of Switching Behaviour After Outdoor Exposure for a Suspended Particle Device Switchable Glazing

Adaptive suspended particle device (SPD) switchable glazing is promising for low energy building application. SPD glazing allows light passes through it in the presence of applied voltage and block light in the absence of power supply. In this work SPD glazing performance after 3 years of outdoor exposure was evaluated. It was found that contrast ratio of SPD glazing before and after exposures changed from 1:11 to 1:10. SPD glazing surface temperature for any transparency level varies between 13 and 40 °C under indoor and outdoor thermal exposure. SPD glazing\u27s surface temperature variation occurs due to the incident radiation level, not for the transmission level of glazing. Voltage and power requirement of SPD glazing did not vary at elevated glazing surface temperature