Abstract:Exergy is applied to the Swedish energy supply system for the period 1970-2013. Exergy flow diagrams for the systems of electricity and district heating as well as for the total supply system of energy and material resources for 2012 are presented. The share of renewable use has increased in both electricity and district heat production. The resource use is discussed in four sectors: residential and service, transportation, industry and agriculture. The resource use is also analyzed with respect to exergy efficiency and renewable share. The total exergy input of energy and material resources amounts to about 2700 PJ of which about 530 PJ was used for final consumption in 2012. The results are also compared with similar studies. Even though the share of renewable resource use has increased from 42% in 1980 to 47% in 2012, poor efficiency is still occurring in transportation, space heating, and food production. A strong dependence on fossil and nuclear fuels also implies a serious lack of sustainability. A more exergy efficient technology and a higher renewable energy share are needed in order to become a more sustainable society.

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Statistical data for the number of sheep flocks and the number of sheep within specific ranges of flock size for New Zealand were exa!llined. Four statistics were capable of enumerating the flock size structure of the New Zealand sheep flock. They were: the median flock size, the median sheep number, the proportion of the total sheep in flocks smaller than the median flock size, and the proportion of the total number of flocks where flock size is greater than the median sheep number. The distribution of labour units v. flock size for New Zealand farms was examined. The proportion of farms having sheep farming as the main enterprise v. flock size was also investigated. It was concluded that new sheep handling systems should be designed to cater for flock sizes of~2000 head.

A work study analysis of common sheep handling operations was undertaken. It was determined that a common sheep handling rate was 300-400 sheep/man-hour. However, the observed rates ranged from 240 to 1143 sheep/man-hour, with the high value achieved when drafting ewes from lambs. Shepherds commonly spent 50-60% of their time treating the sheep and 30-50% of their time moving sheep.