Scientists, trade unions and labour movement policies for science and technology, 1947-1964

This thesis describes the history of the scientific Left beginning with the period of its most extensive influence in the mid-1940s as a movement for the planning of science and ending with the Labour Party's programme of 1964 claiming to harness science and socialism. Its central theme is the external and internal pressures involved in the project to align left-wing politics, trade unions and social responsibility in science. The problematic aspects of this project are examined in the evolution of the Association of Scientific Workers and the World Federation of Scientific Workers as organisations committed to trade union and science policy objectives. This is presented also in the broader context of the Association's attempts to influence the Trade Union Congress's policies for science and technology in a more radical direction. The thesis argues that the shift in the balance of political forces in the labour movement, in the scientific community and in the state brought about by the Cold War was crucial in frustrating these endeavours. This led to alternative, but largely unsuccessful attempts, in the form of the Engels Society and subsequently Science for Peace to create the new expressions of the left-wing politics of science. However, the period 1956-1964 was characterised by intensive interest within the Labour Party in science and technology which reopened informal channels of political influence for the scientific Left. This was not matched by any radical renewal within the Association or the Trade Union Congress and thus took place on a narrower basis and lacked the democratic aspects of the earlier generation of socialist science policy.

Energy saving and solar electricity in fan-ventilated greenhouses

Greenhouse cultivation is an energy intensive process therefore it is worthwhile to introduce energy saving measures and alternative energy sources. Here we show that there is scope for energy saving in fan ventilated greenhouses. Measurements of electricity usage as a function of fan speed have been performed for two models of 1.25 m diameter greenhouse fans and compared to theoretical values. Reducing the speed can cut the energy usage per volume of air moved by more than 70%. To minimize the capital cost of low-speed operation, a cooled greenhouse has been built in which the fan speed responds to sunlight such that full speed is reached only around noon. The energy saving is about 40% compared to constant speed operation. Direct operation of fans from solar-photovoltaic modules is also viable as shown from experiments with a fan driven by a brushless DC motor. On comparing the Net Present Value costs of the different systems over a 10 year amortization period (with and without a carbon tax to represent environmental costs) we find that sunlight-controlled system saves money under all assumptions about taxation and discount rates. The solar-powered system, however, is only profitable for very low discount rates, due to the high initial capital costs. Nonetheless this system could be of interest for its reliability in developing countries where mains electricity is intermittent. We recommend that greenhouse fan manufacturers improve the availability of energy-saving designs such as those described here.