GEOTHERMAL ENERGY - PRESENT STATUS AND PLACE AMONG THE RENEWABLES

Geothermal energy has been produced commercially for over four decades on the scale of hundreds of MW both for electricity generation and direct use. Geothermal resources have been identified in over 80 countries and there are quantified records of geothermal utilization in 58 countries. The worldwide use of geothermal energy in 1999 amounted to 49 TWh/a of electricity and 53 TWh/a for direct use. Electricity is produced with geothermal steam in 21 countries spread over all continents. Five countries obtain 10-22% of their electricity from geothermal. Only a small fraction of the geothermal potential has been developed so far, and there is ample space for an accelerated use of geothermal energy both for electricity generation and direct applications. A comparison of the renewable energy sources (data from the UN World Energy Assessment Report) shows the current electrical energy cost to be 2-10 US cents/kWh for geothermal and hydro, 5-13 UScents/kWh for wind, 5-15 UScents/kWh for biomass, 25-125 Uscents / kWin for solar photovoltaic and 12-18 UScents/kWh for solar thermal electricity. Of the total electricity production from renewables of 2826 TW/n in 1998, 92% came from hydropower, 5.5% from biomass, 1.6% from geothermal and 0.6% from wind. Solar electricity contributed 0.05% and tidal 0.02%. Biomass constitutes 93% of the total direct heat production from renewables, geothermal 5%, and solar heating 2%. Heat production from renewables is commercially competitive with conventional energy sources. The current cost of direct heat from biomass is 1-5 UScents/kWh, geothermal 0.5-5 UScents/kWh, and solar heating 3-20 UScents/kWh. Geothermal energy, with its proven technology and abundant resources, can make a significant contribution towards reducing the emission of greenhouse gases. A brief summary is made on the use of geothermal energy in Iceland and Iran. Geothermal training opportunities in Iceland are furthermore described.

Keywords:

Geothermal , electricity , direct use , renewables , comparison of renewables , energy prices