Energy and climate
Most people agree that the energy sector – notably the burning of fossil fuels – is contributing to climate change. It is a two-way relationship because climate significantly affects energy in a variety of ways. Understanding how climate is changing, together with its influence on energy sources, is crucial.
Because of population growth and industrial development, the potential rise of the global energy demand will not be satisfied by the current foreseen increase in supply capacity.
Developed industrial societies are dependent on relatively cheap and reliable energy. This is not the case, however, for the several billion poor people who rely mostly on biomass (see box below.)
Developing countries face the additional problem of how to rapidly build energy production and distribution systems from a low base. Biomass is important as a heating source, oil still dominates the transportation sector, and coal remains a easy choice for large-scale electricity production. Nevertheless, nuclear, gas, geothermal, hydroelectricity, solar and wind energy are also important in different settings.
Climate change and other environmental impacts are major challenges for the energy industry. International measures necessary to cut emissions of greenhouse gases and avoid the worst effects of climate change are under intense debate. The outcome of these debates will radically alter the technological configuration of the sector.
Globally, the energy industry will be dominated by the drive to increase efficiency and reduce consumption in developed economies and the simultaneous acceleration of energy production in developing countries to provide equitable access for citizens and to support economic development. In both cases, expert information on weather, climate and water will be essential.
Better energy outcomes and lower risks
Whether for future planning, new plant design or minute-by-minute operations, the use of meteorological and hydrological information will improve the outcomes and lower the risks. Successful techniques exist to deal with such things as choosing optimal sites for facilities, controlling environmental impacts, scheduling maintenance and avoiding outages.
National climate databases operated by NMHSs contain a wealth of information that aids countries in planning their climatic resources, risks and requirements. These include supply side questions about how much rainfall, wind and sunshine is available and demand-side questions about needs for heating and cooling, and risk-related questions such as the probability of floods and hurricanes.
Heating and cooling are both major energy users. A simple measure of heating needs is the “heating degree-day”, calculated as the shortfall of a day’s temperature below a comfortable temperature, such as 18 ºC. Tallied over a year, these shortfalls provide the “annual total heating degree-days”. Similarly, “cooling degree-days” can be calculated for days exceeding comfort temperature zones (with adjustments for humidity).
There are vast differences in the heating and cooling needs of countries. In most countries, heating and cooling requirements exhibit significant differences between districts and seasons.
Electricity and extremes
Historical data sets can be used to examine how a planned or existing energy system might perform in the future. This is especially important with climate change and the greater risks of extreme conditions. For example, electricity transmission lines have reduced capacities in high temperatures and may collapse under the weight of ice in winter. Cooling water for nuclear power plants, drawn from rivers, may be ineffective in periods of hot weather, drought and low river flows.
A climate change study for Switzerland indicates that by 2050 there will be a 5–10 per cent reduction in hydropower production due to lower runoff and a decline in cooling capacity for its nuclear power plants.
Energy system managers must deal with these sensitivities to weather, climate and water on a day-to-day basis as well, making decisions that blend historical data with real-time monitoring, seasonal climate outlooks and weather forecasts. As a result, they may run more generators, routing energy through different parts of the distribution network, preparing for extreme conditions such as heat waves, or buying or selling contracts in the energy markets.
In the United States, for example, the demand for heating, ventilation and cooling amounts to about 45 per cent of electricity use and fluctuates according to the unfolding season and day-to-day weather. Wholesale energy prices can fluctuate wildly as a result. Markets for energy futures, which help to smooth the impact of price fluctuations on businesses, make active use of long-range weather and climate information.
Miscalculating the demand for electricity can result in power disruptions, as illustrated by blackouts in the United States and Canada in August 2003. The blackouts were the result of summer peak energy demand exceeding the supply on hand. Energy managers require accurate weather and climate information to help avoid such situations and to manage everyday energy requirements and long-term energy investments and planning.
Renewable energy systems
The use of renewable energies has been growing rapidly, accounting for approximately half of the estimated 194 gigawatts of new electricity capacity added globally during 2010. According to the International Energy Agency, the renewable energy electricity sector grew by 17.8 per cent between 2005 and 2009 and provides nearly 20 percent of total power generation in the world. Hydro power is still the major source of renewable electricty. But wind power has grown the most in absolute terms. The Global Wind Energy Council says the world’s wind power capacity grew by 31 per cent in 2009. In 2010, investment in renewable energy reached a record US$ 211 billion, more than five times the amount invested in 2004.
There is increasing use of cleaner fuels, low-energy industrial processes, low-emission transport, and sustainable housing. Such investments are heavily dependent on quality information on weather, climate and water parameters. Renewable energy production must deal with demand changes and significant supply-side variability, particularly shortages in rainfall for hydroelectricity, lack of wind for wind farms and cloudiness for solar energy installations.
For instance, the curtailment of hydropower generation from Lake Kariba in Zimbabwe as a result of the 1991–1992 drought caused estimated losses in GDP equal to US$ 102 million, a loss in export earnings of US$ 36 million and the loss of 3,000 jobs.
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