Spurred by the economics and politics of oil, the high cost of coal, and the threats of global warming, there has been a big push for renewable energy. Traditional renewable energy sources like geothermal and hydroelectric are no longer enough, and now the push is for more wind, solar, tidal and wave energy generation.
It is estimated that by 2050, there would be 9 to 10 billion people on earth. Today’s urbanized centers will be more crowded than ever before, and there is not enough space to place the required solar and wind generation plants to service the requirements of these urban centers.
Among these bold ideas for power sources, solar energy has been the most promising. Today, the landscape is changing for solar energy with countries like Germany and China leading the way in energy generation. Solar energy lends itself not just to large scale projects, but also for residences and office buildings. In some areas, there are prosumer programs where excess energy generated by the home is sold back to the electric utility.
This is good news for solar energy, as well as for renewables in general. There are more power plants under construction, and new technologies in the pipeline. However, there is a fundamental problem with the numbers being used to compare energy generation sources.
We Need More and Varied Sources of Power
Energy production plants are usually rated according to their capacity. The installed capacity is in kilowatts. In contrast, consumption is in kilowatt hours. This is where energy sources differ. A solar plant may have a certain capacity, but in terms of the power it supplies, it lags compared to other sources. A nuclear power plant may deliver up to 90% of its rated capacity, while a solar energy plant can only deliver up to 12%.
The world has 224,684 megawatts (MW) solar energy installed capacity, with a resulting energy output of 253,593 gigawatt hours (GWh) per annum, which is equivalent to 11%. Germany, which is a leader in solar energy generation, has a capacity of 39,784 MW with an energy output of 36,056 GWh, equivalent to a factor of 10.3%.
One of the causes of this is the intermittency of solar energy. Plants cannot generate power when the sun is down. This is also true for wind and tidal energy, as there are conditions when these sources cannot generate energy. The use of batteries can only help in supplying energy after dark, but not in generating power.
Solar as well as wind turbines can help consumers as they generate power for their own use. However, for the future, there would still be other needs which would require more energy production from centralized sources. As countries become more affluent, they would be using more energy. In addition, due to global warming, there is more need for air conditioning. These are pressures on the energy grid which have to be addressed accordingly.
Centralized energy production and transmission will not go away anytime soon. Even if home power generation becomes the norm, there will still be a need for a large central power plant to serve the community. It is estimated that by 2050, there would be 9 to 10 billion people on earth. Today’s urbanized centers will be more crowded than ever before, and there is not enough space to place the required solar and wind generation plants to service the requirements of these urban centers.
The percentage of renewable power supply would grow, but so would other large energy systems like hydroelectric, geothermal, and nuclear power plants. The energy these centralized big plants would generate would help feed the increasing demand. A diversified energy platform would happen due to the need to meet demand and this would leave a bold impact on the world’s energy supply.
