22 production capacity of electricity will not be as great as when many heating systems without storage capacity are used. If wood is used as a fuel it becomes possible to choose a suitable time for firing. For single house solar energy systems the investment costs are given as approximately 2 Sw. Crs per annual kWh (8). The Swedish Council for Building Research indicates 1 - 6 Sw. Crs per annual kWh for solar heating systems (37). These costs include solar collector, storage tank, pipes etc plus installation. Other estimates indicate that the costs are approximately 1,000 Sw. Crs/m2 solar collector surface for a complete system (24, 40) including storage etc where the total cost has been worked out per m2 area of collector. It is considered possible within the near future that prices will be down to 500 - 750 Sw. Crs per m2 (24, 40, 41). It is perfectly feasible to utilize approximately 20 50% of the solar radiation in solar heating systems (200-500kWh/m2). 500 Sw. Crs/m2 above is equal to 1 2.5 Sw. Crs per annual kWh. The annual cost for running and maintenance is given as approximately two percent of the investment (40). Since it is easier to achieve good economy in larger solar heating systems due to the economy of seasonal storage there is an interesting connection to district heating systems and in particular to hot water plants for a few hundred flats. Well developed district heating systems could facilitate the introduction of solar heating if the pipes are dimensionized for lower water temperatures than is the case today. The need for hot water during the summer months is a market for solar heating which could develop early. It is already today economical compared to certain alternate heating systems. District heating systems that during the summer months only produce hot water with low efficiency could perhaps be supplemented with hot water production from solar heating systems. This could create a good market for solar heating systems within a relatively short period of time. In chapter 1 we noted that society is facing a change of energy source away from dependence on oil. Such a transition takes several decades. In order to meaningfully discuss the potential and possibilities for the ultimate energy sources it is necessary to start by discussing how the future society that these energy sources will serve could look. How much energy is needed and for what purposes? Future development of society is today very uncertain. In the nineteenfifties and sixties the course was relatively well charted towards increasing material standard,which was to be gained mainly by technological advances. Today the future course is not as clear. One can note that the range of possible societal development within the next 30 to 40 years is great. This complicates discussions on future energy systems. We have chosen a future society of the same type as today ́s as our point of departure. The reason for this is that we want to simplify the discussion by not making an alternate development of society a premise for the discussion of a renewable energy system. This does not mean that we are stating a position on the issue of changes of society, e.g. towards a society with better resource use and consequent probable lower energy need. We do mean, however, that if Solar Sweden is a possibility without postulating changes in the type of society we have, it is also a possibility e.g. in a more resource conserving society. It is thus simply a method for not making the discussion on coal and/or nuclear power on the one nand and renewable energy sources on the other dependent upon a total discussion of the social structure with all its implications. We will here sketch a hypothetical Sweden such as it may look in 3-4 decades. We assume that the production of goods and services in the country are double the present (an increase of 100 %). This is equivalent to an annual growth of approximately 2%. A change in the relationship between production of goods and services is of course not improbable but it does not alter the picture of tne main features of the energy system. The number of inhabitants is postulated to be basically unchanged. The energy need per produced unit is assumed to be diminishing. Already today's energy prices lead to a more efficient energy use and the costs of energy can be expected to rise further. In industry (the sector producing goods) the specific energy use is assumed to be 80% of today's level (43). For the services sector, which includes transportation of goods and people, trade, public services (hospital, schools etc) the energy use per produced unit is assumed to be half of that today. This presupposes a halving of the energy use per km in the transport sector. The possibilities for achieving this reduction will be dealt with later (section 4.3.2). The energy use in other parts of the service sector consists largely of space heating, where the possibilities for more efficient energy use are substantial. Housing is dealt with separately since the energy needs do not mirror either that of production of goods or services. An increase in the number of flats (including single houses) with 40 % (and with a certain increase of area per flat) has been assumed. By better insulation in houses produced in the period 1977-2015 and measures taken in houses existing in 1977 and still remaining in 2015 the average energy need per flat (single house) is assumed to be reduced by 30 %. 25 We have not made any attempt to balance more efficient energy use We consciously avoid introducing the concept of living standard into the picture we paint. That depends on how different individuals value different activities or goods. What level of living standard the production here assumed brings is not possible to say in a perspective of 35 years. It could mean that everybody gets double the amount of goods and services compared to what they get today. Or it could mean that everybody gets roughly the same amount of goods and services per capita as those 10% of the population that consume most get today (69). The increased wealth could be used for shortening the working week. If international solidarity is valued highly some of the production of goods could constitute aid to developing countries. It is thus possible to imagine many different types of production that could all be contained within the production volume assumed above. We would like to stress again that we have chosen a level of material standard, which by many people perhaps will be seen as high in order to discuss the characteristics of Solar Sweden with such a development. A direction of development which leads to lower energy use would make it simpler to introduce a renewable energy system. 26 Table 3.1: Assumed production of goods and services and specific energy use 2015 with 1975 as base year. 1) of which space heating approximately 40 TWh 2) of which space heating approximately 31 TWh 3) Energy Conservation Committee, Report 1976.12.15, rounded figures 4) Losses in electricity distribution and refineries 5) The figure is a consequence of the design of the energy system and is discussed below. Losses occur mainly in domestic methanol production, cf figure 4.1 |