5 With approximately 5 MWh/ton dry matter and an average yield of An alternative way of estimating the very uncertain costs for biomass from energy plantations is the following. In agriculture and fishery the total work was 316 million hours (66). There are 3 million ha of arable land, which means that on average 105 hours/ha was put into agriculture. Assume that energy plantations are 1/3 as labour intensive. This would be equivalent to 35 hours per ha. The people indirectly occupied (making machines, fertilizers etc) is estimated to be in the same order of magnitude as those directly employed. This would mean approximately 70 work hours per ha. Rate of plantation 1990 - 2003: 100,000 ha/year 2004 - 2013: 150,000 ha/year A total of 2.9 million ha is put under plantations. Harvest takes place after 2 years. The figure 88 work hours per ha totally has been used in our calculations. This gives a total need for 255 million work hours for planting the entire area. A total of approximately 55 TWh comes from aquatic biomass (algae), straw, reeds, logging waste and domestic solid waste etc. For logging waste the costs are given as 220 - 240 Sw. Crs/ton dry matter (12). 54-948 O 6 We have assumed that this cost represents a cost for all these All the straw, reeds, logging waste and domestic solid waste (a total of 35 TWh) is assumed to be available by 1990. Aquatic biomass is started in 2006 with an annual increase of 10,000 ha/year. 4. Other electricity production 4.1 Combined generation and district heating systems Combined generation and district heating systems are assumed to Approximately 8 GW are assumed to be needed at a cost of around 2,000 Sw. Crs/kW (110). This gives a total of 16 billion Sw. Crs. - 80-56 7 Assume that in this case also half is in engineering and half in construction industry. This means a total of 248 million work hours (of which 125 million is direct labour). Assume a build-up of 500 MW per year during 2000 - 2015. This gives 15.5 million work hours per year. 4.3 Pump storage (or other technology for storing electricity) Assume that 15 GW are needed costing 800 Sw. Crs/kW (111). This gives a total of 12,000 million Sw. Crs. If work/Sw. Cr as above, we get a total of 186 million work hours (of which 93.6 million directly). Build-up of 500 MW/year during 1985 - 2015, i.e. 6.2 million work hours/year. 77 TWn of methanol are produced annually, which is equivalent to approximately 16 Mtons. A plant which produces 750,000 tons per year of methanol is equivalent to about 3.5 TWh, and is assumed to cost 1,100 million Sw. Crs in investment (112). This is true for production based on coal and is assumed to be the same with biomass. Construction of one plant per year for 22 years meets the need. The first plant is assumed to be constructed in 1990. Half of the investment is assumed to be in production industries and half in construction. This entails an annual labour need of 8.6 million work hours directly and a total of 17 million hours per year for 22 years. 1986-1990 the equivalent of 0.1 TWh/year is built 8 The total capacity installed in the year 2015 is equivalent to a contribution from solar heating of 71.5 TWh per year. The figure used for investment cost is 2 Sw. Crs per annual kWh (cf section 2.5). Assume that production and installation of solar heating systems consists of 50 % engineering industry and 50 % building industry. = Cf an American study, where the labour need for solar heating is given as 4,100 - 5,700 work hours/MW year 0.47 0.65 work hours/MW hour (113). At a mean life of 20 years, the investment is equivalent to 0.009 work hours per kWh and year direct work, which is approximately 40% under the value we have used. Installation of 1 TWh per year costs 2,000 million Sw. Crs, and 15.5 million work hours directly and a total of 31 million work hours. Running and maintenance For windpower, solar cells and solar heating we have used an REFERENCES AND NOTES A large proportion of the references used for this study is in 1. Måns Lönnroth, Thomas B. Johansson, Peter Steen: 2. 3. 4. "Energy in transition" - a report on energy policy and future Peter Steen: "On the Oil Supply." Secretariat for Future Bert Bolin: "Energy and Climate". Secretariat for Future A. Björkström, B. Bolin, H. Rodhe: "Report to the Energy Commission Group A, Safety and Environment", Stockholm 1977 (Swedish) Thomas B. Johansson: "On the Nuclear Fuel Cycle". Secretariat for Future Studies, Stockholm, 1976 (Swedish). 6. "Report to the Energy Commission, Group A" by Jon Elster: problems". (Norwegian) Paul Hofseth: "Energy Policy Decisions - Some elementary Torbjörn Thedéen et al.: (Working group for risk assessment and M. King Hubbert: "The energy resources of the Earth", Scientific F.J. Dyson: "Energy in the Universe". Scientific American 224, G. Gustafson, S. Lyttkens, S.G. Nilsson: "The energy forms in |