Sunshine Mapping From Space Means Brighter Solar Energy Future

Jul 01, 2005

How sunny is it outside right now – not just locally but all across Europe and Africa? Answering this question is at the heart of many weather-related business activities: solar power and the wider energy sector, architecture and construction, tourism, even health care.

Today accurate and continent-wide scale measurements of ground radiances are provided every 15 minutes by ESA's Meteosat Second Generation satellite.

Integrating this information with the business practices of solar energy managers is the objective of the ENVISOLAR project (Environmental Information Services for Solar Energy Industries), funded by ESA within the framework of the Earth Observation Market Development Programme (EOMD).

Solar energy has switched from a green aspiration to a solid business. The solar market in photovoltaics – the direct conversion of sunlight to electricity – has an annual turnover of 600 million euros in Germany and 1000 million euros in the rest of Europe.

The latter figure is predicted to increase to 2500 million euros by this decade's end. Furthermore, thousands of megawatt of renewable energy potential are also available in Africa, Asia and Central America as shown by the Solar & Wind Energy Resource Assessment (SWERA) project of the UN Environment Programme (UNEP).

There are two kinds of solar energy establishments: solar thermal plants which concentrate heat from the Sun, and photovoltaic plants that convert sunlight into electricity.

In both cases precise, long-term irradiance data is needed for choosing plant locations and estimates of likely energy yield for prospective investors. Then once a plant is built, managers need data updated in near real-time to check the facility is working optimally, and energy output tallies with available sunshine.

"Today our audits form the basis of huge investments in the range of 50 million euros for single projects," explains Gerd Heilscher from Meteocontrol, a company auditing photovoltaic systems and involved in ENVISOLAR.

"Besides the layout, solar radiation is the most important issue. But unfortunately only a few high-quality ground-based measurements are available at this time."

Within the wider energy market, such information is also valuable for forecasting electricity load – irradiance is the other major environmental influence on demand besides temperature.

How best to measure sunlight? Ground radiance is quite complex to quantify as it is influenced by much more than simply a site's distance from the equator. Variations in cloud cover, humidity, aerosols and ozone in the air determine the amount of incoming solar radiation actually reaching the ground.

Local topography is also important and there are large regional differences – in Europe the southern side of the Alps receives twice the annual radiance of northern slopes.

Measuring from below using in-situ data is technically demanding, expensive on an ongoing basis and limited in coverage – there are only around 200 solar-energy-measuring stations to cover all of Europe and Africa in the official networks affiliated to the World Meteorological Organisation (WMO).

Measuring from above using satellites provides a wide-area, objective and cost-effective solution. Research by MeteoSwiss has shown that satellites are even more accurate than ground measurements once the distance to the next ground station is greater than about 30 kilometres.

Today, ENVISOLAR partners are developing and marketing a variety of solar services based on satellite radiance data. These services benefit from the latest scientific results and state-of-the-art algorithms developed by a EU Research&Development project called Heliosat-3.

ENVISOLAR services based on these data products comprise solar plant yield estimates, plant fault detection and performance checking, energy forecasting for energy utilities, and time series services including maps and statistics of irradiance, its direct and diffuse components and spectral components such as illumination.

Customers of ENVISOLAR services include SAG Solarstrom AG, a publicly quoted German firm that builds and operates photovoltaic installations, providing entire financial investments in photovoltaics to its customers.

"We need solid information for investment decisions, especially with regard to future markets like Spain," said Uwe Ilgeman, CEO of SAG Solarstrom AG. "The sampling and spatial resolution of ground-based data is too coarse – for example in Spain there are only 30 sites available at the moment."

High-resolution radiance data from the Solar Energy Mining (Solemi) service operated by the German Aerospace Centre (DLR) - leader of ENVISOLAR - have contributed to the quantification of the renewable energy potential within 14 developing countries, in the framework of the SWERA project of UNEP. Results of SWERA suggest the potential is far greater than has previously been supposed.

"These countries need greatly expanded energy services to help them in the fight against poverty and to power sustainable development," said Klaus Toepfer, Executive Director of UNEP.

"SWERA offers them the technical and policy assistance to capture the potential that renewable energy can offer."

A wide range of users besides climate scientists can benefit from EO-based solar services, in particular farmers, architects interested in knowing locally appropriate window sizes, and even PVC manufacturing companies.

One of these, Deceuninck, used the ENVISOLAR Solar service (SoDa) to study how the ultraviolet in sunshine degrades PVC building parts, so that their warranties could be tailored to local conditions.

Medical researchers are using sunshine maps to investigate links between sunlight and health. The International Agency of Research on Cancer (IARC), an institute of the World Health Organisation (WHO) is probing the relationship between ultraviolet radiation exposure and skin cancer.

And scientists at the UK's University of Southampton and the Royal London Hospital have also used the data to study whether lack of vitamin D – supplied through sunlight – in pregnant women contributes to osteoporosis or 'brittle bone syndrome' in later life.

Another EOMD project called HappySun Mobile is also applying satellite-based sunlight data to public health care.

With exposure to sunlight being the leading cause of melanomas and other skin cancers, this one-year project will set up a means of generating automatic warnings about safe sunbathing times based on measured ultraviolet levels, and deliver them to sunbathers via text messaging.

Source: ESA

Explore further: NASA spacecraft nears historic dwarf planet arrival

add to favorites email to friend print save as pdf

Related Stories

Demonstration of "CrystEna" energy storage system

Feb 26, 2015

Hitachi America, Ltd., a wholly owned subsidiary of Hitachi, Ltd. and Demansys Energy, Inc. ("Demansys"), a smart grid technology company with offices in Connecticut and Troy, New York, announced today that ...

Hotel robots in Japan will perform a range of tasks

Feb 08, 2015

This summer, you could be walking into a theme-park hotel to find the greeter is not a person but a robot. Once you stop rubbing your eyes, you will see that a robot appears, to carry your bags to your room. ...

NOAA's DSCOVR: Offering a new view of the solar wind

Feb 06, 2015

There's a fascinating spot some 932,000 miles away from Earth where the gravity between the sun and Earth is perfectly balanced. This spot captures the attention of orbital engineers because a satellite can ...

Recommended for you

Far from home: Wayward cluster is both tiny and distant

5 hours ago

Like the lost little puppy that wanders too far from home, astronomers have found an unusually small and distant group of stars that seems oddly out of place. The cluster, made of only a handful of stars, ...

Why don't we search for different life?

9 hours ago

If we really want to find life on other worlds, why do we keep looking for life based on carbon and water? Why don't we look for the stuff that's really different?

OSIRIS catches glimpse of Rosetta's shadow

10 hours ago

Several days after Rosetta's close flyby of comet 67P/Churyumov-Gerasimenko on 14 February 2015, images taken on this day by OSIRIS, the scientific imaging system on board, have now been downlinked to Earth. ...

Kamikaze comet loses its head

11 hours ago

Like coins, most comet have both heads and tails. Occasionally, during a close passage of the Sun, a comet's head will be greatly diminished yet still retain a classic cometary outline. Rarely are we left ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.