The development of renewable energy in Ireland is influenced by policy in a number of areas. Among the objectives of Irish energy policy are the development of native resources and ensuring security of energy supply. At present, Ireland imports about 70% of its total energy requirement, and this figure is likely to rise to 90% in about five years, when the Kinsale natural gas supply becomes exhausted.
From an environmental point of view, burning fossil fuel gives rise to pollution problems which are a cause of increasing concern. Oxides of sulphur and nitrogen combine with atmospheric water vapour to produce sulphuric and nitric acid which fall as ‘acid rain’, with serious consequences for plant and marine life. Carbon dioxide, which is produced in large quantities when fuel is burnt, is a potent ‘greenhouse gas’ and is thought to be responsible for around 60% of the problem of global warming. The EU has set targets for the reduction of all these emissions. The use of renewable energy sources simultaneously reduces energy imports and helps to protect the environment.
There are many different sources of renewable energy. Some, such as hydropower, have been exploited for a long time and are well developed. Indeed, when the Ardnacrusha hydroelectric scheme on the river Shannon was commissioned in 1929, it supplied almost all the country’s electrical demand. Others, such as the wave power which Ireland has in abundance off its west coast, will surely play an important role in the future; however, at present much research remains to be done. The two technologies which seem to be coming of age in the 90s in Ireland are wind power and biofuels.
Figure 1: Planned Wind farms in Ireland
The fact that wind turbines do not produce atmospheric emissions does not mean that they are without environmental impact. Certainly the prospect of hundreds of these machines in areas of outstanding natural beauty is one that many people would find unacceptable. The Mount Eagle scheme was objected to, and the necessary planning permission was only obtained after a difficult and expensive appeal procedure. A proposal for a windfarm in County Tipperary has met with a vigorous and well organised opposition campaign. It seems most unlikely that planning permission will be granted for the project. Some say that people now will object to anything and that the NIMBY syndrome (Not In My BackYard) has grown into the BANANA syndrome ( Build Almost Nothing Anywhere Near Anyone). A sensible middle ground would seem to be to involve local groups, including tourist interests, in discussions at the planning stage of potential projects, and to avoid areas of particular sensitivity.
The ESB has given impetus to the development of renewable energy sources via its Alternative Energy Requirement. This was a competitive scheme intended to develop 75 MW of new generating capacity from renewables, about 30 MW of which was expected to be from wind. As well as some capital funding, the ESB offered long term contracts to buy the power produced. The result of this scheme was announced in March 1995. Among the projects submitted were ten wind farms which did not request any capital grant. It has been decided to support all of these by way of guaranteed power purchase, amounting to 73 MW, much more than had been expected. This indicates the maturity of this technology. A similar scheme in Northern Ireland has already been completed and six wind farms totalling 30 MW are either in the planning or construction stage. It can be expected then, that in two years or so the total installed capacity of wind generated electricity on this island will be around 110 MW. While this must be kept in context - the coal fired station at Moneypoint, Co Clare, the largest in the country, is capable of producing 900 MW - this still represents a sudden and dramatic increase in wind power, a great deal of fuel saved and substantial reduction in environmental damage.
European agriculture has, in many ways, been a victim of its own success, and the problem of overproduction of food within the EC has led to a change in the payment system to farmers. Area payments are now made to tillage farmers who agree to ‘setaside’ a proportion of their land, i.e. they must not grow food on it in order to avail of subsidies. The growing of so-called ‘energy crops’ is, however, permitted on setaside land subject to certain conditions. One such crop is Rape, the oil from which can be used as a diesel substitute.
This is hardly a new idea. When Rudolf Diesel first demonstrated his new invention, the compression ignition engine, at the Paris Exposition in 1900, he fuelled his prototype with ground nut oil. Modern diesel engines however have been developed specifically for fossil-based diesel, and although they will run for some time on raw rape seed oil, they eventually suffer problems of coking of the injector tips and degradation of the lubricating oil. There are two possible solutions to this. The first is to modify the engine. The Elsbett engine is such an engine, developed in Germany, which will run successfully on a range of fuels. The difficulty with this solution is in achieving the level of mass production needed to make these engines commercially viable.
The second method is to modify the oil. The relatively simple chemical process of transesterification (Figure 2) produces rape methyl ester (rme), which has properties almost identical to those of fossil based diesel. The by-products of this processing are oil-seed cake, a high protein animal feed, and glycerol. A third possible approach is to simply remove the impurities from the raw oil and use it as a blend with diesel at a rate of 20% or more.
Research in Ireland has been spearheaded by Teagasc at their research station in Oak Park, Co Carlow. Tests carried out to date include running an Elsbett-powered light transporter running on raw rape seed oil, and running a similar vehicle with a conventional diesel engine on rme. Tests were also performed with conventional diesel fuel to provide a basis for comparison. Dynamometer tests and exhaust gas analysis carried out at the University of Limerick have shown virtually identical power output and fuel economy, and less smoke, with virtually no sulphur dioxide emissions. (See Table 1 and Figure 3). Additionally most of the greenhouse gas carbon dioxide which is released on combustion is recycled by the growing crop.
The present phase of the Teagasc project, which is funded by the EU, has two main objectives. In order to gain experience, a number of potential users are currently running vehicles on biodiesel: Bus Eireann in a single decker bus in Cork, Waterford Foods in a ten ton rigid, and a twenty five ton articulated truck, Emerald Star Line in a pleasure cruiser on the Shannon, and Glenveagh National Park in two of its mini-buses. The involvement of the last two participants indicates a further advantage of biodiesel. The consequences of fuel leaks or spillages are much less severe than with diesel, as 98% is broken down within 21 days. Between them these vehicles have travelled over 100,000 km with few technical problems.
In an attempt to reduce production costs, which is the other Teagasc objective, methyl esters from the plant carmelina sativa and from waste cooking oil are being investigated. Carmelina gives similar oil yields to rape, with less inputs; and waste oil would be a virtually free feedstock. A light transport vehicle has travelled 18,000 km on waste oil ester to date. Although there remain problems to be overcome, both of these feed stocks appear promising.
The main barrier to widespread adoption of this technology is cost. Teagasc have estimated the present production cost of rme as 26p/L. The corresponding cost of fossil based diesel fuel before tax is around 11p/L. The EU has made a recommendation that tax on biofuels should be reduced to 10% of that applying to fossil fuels. This would amount to a subsidy of about 20p/L and would clearly make rme viable. Some European countries have already enacted this tax concession. In France, 55 cities have fleets of buses running on rme, and annual production is heading towards 200,000 tonnes. Austria produces a similar quantity and Germany produces more than 100,000 tonnes per year, with Italy not far behind. Some urgency attaches to Ireland’s situation due to the fact that the GATT world trade agreement limits EU total production of rape seed oil to about 1,000,000 tonnes per year. With continued rapid development of the industry elsewhere, this limit may be quickly met and countries which are not involved may lose the opportunity to do so.
It is clear that the future of the biodiesel industry in Ireland rests in the hands of the policy makers.
Tony Kay is a Lecturer in Mechanical Engineering. His research interests are in the areas of renewable energy and energy conservation.
