CleanTechnica blog describes the recent signing of the DESERTEC proposal, an action that will see the sun of Africa power that continent and 15% of Europe, it is anticipated.

You can learn more about the DESERTEC Project here.

Solarkent has produced the Renewable Energy Map UK – a online map that uses Google to show the renewable and alternate energy projects in the UK. At first glance the sheer number of projects and sites is amazing. There is a significant amount of this work in the UK and sites are evenly spread throughout the country.

Solarkent operates additional web sites and readers may be interested in exploring them.

EURACTIV discusses the issue of solar energy production from the African Sahara desert. There has been a long history of discussion about such a project or series of linked projects, although technological and political issues have been prominent.

Even though a small area would be needed to development such a site, these issues are not readily overcome. The feasability of such projects is significantly related to economics.

The world’s largest solar energy project is being proposed by a consortium of 20 firms as Munich Re reports. Other partners would include Siemens and Deutche Bank. The project partners plan to meet in July to discuss the proposal of producing North African solar energy.

From the article - A German-led consortium wants to fund an international solar-energy plan to the tune of €400 billion. The idea is to gather solar heat in North Africa and send the electricity to Europe. If it works, it would be the largest green-energy project in the world.

Many renewable energy sources provide intermittent power that can fluctuate with weather and time of day. Wind power can vary considerably with the seasons. Solar power is affected by cloud cover, and obviously can’t produce power at night. Hydro power is also somewhat variable dependent on rainfall levels. These fluctuations of power supply need to be factored much differently than the traditional power sources that can be dispatched and can be made to produce more power as demand increases.

As more of these intermittent energy sources come online, it becomes increasingly important to understand the base line of power that these sources can generate. Significant seasonal increases of renewable power  would allow a utility to decrease their power generation from less clean sources. Prolonged weather events  can curtail renewable power and must be planned for in order to avoid disruption in service.

Predicting Reliability

Historical weather data provide a key metric to predict power supply from renewable energy. The most effective strategy is to develop sophisticated and long-term weather models prior to renewable energy siting decisions. These models, along with  sensors at the power source, provide a means for close monitoring and performance evaluation.

Different sources of renewable energy require different levels of modeling and prediction. Some renewable sources are very variable and others are much more consistent.

Wind power is much more variable than solar. Wind speeds, wind direction, and air density all factor into wind turbine performance. Turbines depend on consistent mid-range wind speeds, because if the wind is too low it can’t generate electricity and if it’s too high the turbines need to be shut down to avoid damage.

Solar energy is an easier energy source to predict, because the amount of light energy in a specific spot is fairly consistent, with some seasonal fluctuation, but greatest intensity in times of greatest demand. Power producers are working on ways to extend the availability of solar power after dark by deploying such ideas as thermal power generation and storage. Generating steam from the sun rather than direct conversion to electricity provides a more consistent and longer lasting power.

Hydro power is one of the more consistent and reliable renewable energy sources. Hydro plants that rely only on river flow aren’t all that common, with most drawing on a water reservoir for more consistent power.

Location Factor

Location is the most important factor when determining the variability or consistency of renewable energy. Siting renewable energy close to the source, but also close to demand, is a problem that require spatial analysis and modeling in order to optimize the performance and predictability of the power source.

Areas with consistent wind are typically at higher elevations or closer to the coast, and sea breezes are much more predictable and consistent than breezes on land. Solar power relies on clear skies, and some areas are much more ideal than others given their amount of sunshine. Hydro power relies on consistent and abundant water sources in areas that aren’t susceptible to drought.

A single wind turbine will be much more variable than a large array of turbines that are gridded together. Solar power can be complementary to wind, because wind is often strongest at night and during cloudy weather. Wind can also be a good complement to hydro power. As more renewable energy comes online, there will be a number of strategies deployed to balance intermittent supply with demand, and to align different sources to ease fluctuation.

The larger the electric grid, the less a factor intermittent power is to the overall grid. But with large percentages of renewable power on smaller grids, the grid design needs to made more intelligent and adaptable in order to manage fluctuations.

The viability and reliability of prediction models will improve over time as more data is collected and analyzed. The most variable, and most efficient, source of wind power is relatively new and the models are improving significantly each year.

Forecasting and predicting demand and supply are going to be of increasing importance as our power generation sources become more diverse and more distributed. Matching power demand with a wide variety of power sources also calls for a more sophisticated and intelligent transmission and distribution network.

Resources

3Tier, a company that does global renewable energy assessment and forecasting

Siting Renewable Energy Facilities: A Spatial Analysis of Promises and Pitfalls, Shalini Vajjhala, Feb. 2006

The German government says that Bonn based SolarWorld AG is the country’s fastest growing company in 2008. While providing goods and services within Germany, Solarworld AG operates largely around the world, particularly across Europe and China. “SolarWorld AG’s main business area lies in solar power applications for domestic house roofs as well as large installations in Germany, Europe and the growing solar-power market of the future, the US. SolarWorld also funds power access in regions of the world far from any electricity supply grid, such as in western China, where the company has powered up more than a hundred villages that were isolated from the national power supply.“

Jimmy Carter installed 32 solar hot water panels in 1979 in an effort to spur a move toward renewable energy and independence from foreign energy sources. The panels were removed by the Reagan administration, and Google tracked the panels to Unity College and now have one of the panels on display at their Washington, D.C. office.

Google is making a strong commitment to a clean energy future, and this effort is one of many to raise awareness of what American enginuity might achieve. Read more about Google’s effort here.