Solar Software Challenge: Making Solar Databases Accessible

The market for software for the renewable energy industry has expanded dramatically during the past 20 years. These days it’s not good enough to build a power plant in a sunny part of the world and hope for the best.

It’s now more important than ever to know exactly the best place to site a facility and to have an accurate understanding of how much energy it stands to produce based on rigorous meteorological and database analysis. The good news is that the latest software offerings allow engineers, site managers and even those with little training to do just that.

One of the leading companies is Berlin-based Dr Valentin EnergieSoftware, founded by Dr Gerhard Valentin, who is also the current managing director.

The first program was launched in 1993 under the name of T*SOL (solar thermal). PV*SOL (photovoltaics) was first released in 1997. Today the programs of both product lines are sold in more than 70 countries worldwide. Recently updated, PV*SOL Expert is typical of the company’s products. It is essentially a dynamic simulation program with 3D visualisation and detailed shading analysis for PV systems.

With the new 3D object ‘open area’, ground-mounted systems (with up to 2000 modules) can be reproduced on a slope or level ground in PV*SOL Expert’s 3D visualisation. This means that, in addition to the differentiated shading analysis of mounted PV systems on buildings – which has been possible since version 5.0 – the corresponding shading analysis can now be carried out for ground-mounted systems.

An ‘open area’ can, however, also be used to align a number of 3D objects together. For example, you can use an open area to position or adapt 3D objects such as trees, buildings, bay windows, walls that are fixed or can be rotated, round chimneys, all types of barred areas, as well as edge distances and inspection paths.

Furthermore, in 3D visualisation the new version PV*SOL Expert 5.5 offers the possibility of joint configuration of a number of PV areas as well as manual configuration (in addition to automatic). A meandering course for the individual strings is possible.

US measurement units have also been introduced in the new version – in Photo Plan, 2D roof design and 3D visualisation. All of the PV*SOL programs include extensive module and inverter databases now containing more than 10,000 modules and 2100 inverters, which are continually updated and expanded by the automatic-update function. The data is updated online by the module and inverter manufacturers. Valentin Software checks the data, then makes it regularly available.

Expanding Enterprise

Dr Valentin EnergieSoftware is now focusing on expanding its business in the US and it opened a branch office in California in 2009.

‘Although North America’s share of the global solar market is on the small side, at 15%, our company has a long-term focus in this key market,’ says Dr Valentin EnergieSoftware spokeswoman Silke Reichmann de Salas. ‘We supply solar experts with reliable and easy-to-use programs with which they can tap into and develop new customer markets.’

One such program is PV*SOL basic with Photo Plan. This allows solar contractors, sales representatives and engineers to design PV systems from digital photos of customer’s homes or office buildings and to create professional proposals containing detailed financial analysis and photo-like graphics of proposed systems.

‘Two of the greatest challenges facing the solar industry today are how to reduce system prices and how to increase the mass market adoption of solar,’ said Paul DeKleermaeker, Valentin Software’s North American general manager. ‘We’ve developed this tool to help address these needs while also offering contractors a resource to increase their productivity.’

The company says this means that contractors will save time traditionally spent on tracking solar incentives, electricity rates, product specifications and climate data, while also saving time on employee training.

In order to introduce customers to its products, the American division is now hosting free monthly introductory webinars, as well as individual customer walk-throughs.

The online webinars are designed to give potential and current customers an overview of Valentin Software’s most popular programs, while every other month webinars are given on GeoT*SOL basic.

‘These introductory webinars provide valuable training to help jump start the use of Valentin Software’s program, as well as answering questions most frequently asked by beginners,’ says de Salas. ‘The webinars are equipped with a chat function,’ he says.

New Arrivals

While Dr Valentin EnergieSoftware remains at the forefront of the industry, recent years have seen the arrival of some new kids on the block who are determined to carve their own niches in the software market.

One such newcomer is Slovakia-based GeoModel Solar, a developer and operator of what the recent IEA SHC Task 36 data inter-comparison activity called ‘the best performing solar radiation database presently available on the market’.

The major strengths of the database, known as SolarGIS, are the balanced statistical representation of the values (histograms), very good accuracy in GHI and excellent accuracy in DNI. SolarGIS contains high-resolution solar and meteo data, which are routinely updated, and a set of tools for PV planning, monitoring, performance assessment and forecasting.

Daniel Ranusa, business development manager at GeoModel Solar, says, ‘Our software is not in a competition to applications such as PV*SOL or PVsyst, rather it is complementary. For example, PVsyst recommends to their users to use SolarGIS and meteorological data.’

GeoModel Solar also recently delivered a solar assessment study for the 5 GW solar park in Upington, South Africa. To conduct the study, GeoModel Solar analysed the measured data along with 17 years of satellite-derived solar data to predict the solar resource available at the solar park.

Interactive Mapping

One of GeoModel Solar’s key products is iMaps – an online map-based interactive tool for solar site prospecting. iMaps are designed to provide fast access to key solar resource parameters available in the SolarGIS database at spatial detail of 250 metres, thus allowing for accurate data query, sites selection and comparison, and informed decision making about the best position for a prospective project.

iMaps shows information in a spatial context, with access to other geographical data and maps. A user can better understand regional changes resulting from mountains, terrain shading and elevation. Project developers can quickly and easily identify sites with high irradiation to maximise electricity production and economic profitability of solar energy projects, the company claims.


SolarGIS has also been extensively validated by a number of local ground measurements in partnership with the Centre for Renewable and Sustainable Energy Studies, Stellenbosch University. ‘These maps are a very useful source of solar resource information. Utilisation of such information can have a significant impact on profitability and efficiency of projects,’ says centre director Professor Wikus van Niekerk.

Ranusa is targeting global coverage by the end of 2012. ‘At the moment we’ve got Europe, the Middle East, India and China and in the next month we’re going to add Argentina, Brazil and the US and we expect to have global coverage by the end of the year,’ he says.

GeoModel Solar’s other key product is pvPlanner – an online simulation tool for planning and optimisation of photovoltaic systems. Once a site is selected in iMaps, photovoltaic electricity yield can be interactively estimated by pvPlanner.

The pvPlanner then allows fast comparison of various sites and PV technology options. It helps in choosing between different types of modules, inverters and mounting strategies and allows accurate estimation of electricity production needed for financial assessment. For each simulation the data and reports can then be stored.

Quality Is in the Database

Geneva-based PVsyst was founded by Andr√© Mermoud, author of PVsyst software and the company’s current CEO. While the company only started trading in March of 2011, and currently only employs five people, Mermoud says that the technology behind the software has been a long time in development.

In 1992 Mermoud began developing PVsyst software for the study and simulation of photovoltaic systems. He developed a tool for 3D shading constructions, the simulation of standalone PV systems, and then pumping PV systems (including modelling of batteries and pumps). He has also conducted research for specific models of PV module of any available technology.

PVsyst’s offering is engineer-oriented and aimed at performing a thorough system design using detailed hourly simulations. This offers the user a large database of PV components, location and meteorological sites, definition of the plane orientation (with possibility of tracking planes, double-orientation or shed/sun-shields mounting) and an expert system to facilitate defining the PV system layout.

The system also allows for detailed parameters allowing fine effects analysis, including thermal behaviour, wiring and mismatch losses, real module quality loss, incidence angle losses as well as horizon definition for ‘far shading’ calculations and a 3D tool for ‘near shading’ detailed studies. The 3D tool allows the user to draw the geometry of the complete system. It computes a shading factor for beam components as a function of the sun’s position. The shading for the diffuse is taken into account using an integral of the shading factor over the sky portion seen by the array.

It is also possible to partition the array in order to evaluate the electricity losses due to the string layout. Animation over a whole chosen day clarifies the shading impact of a given situation.

To make the financial calculations easier, PVsyst also offers a detailed economic evaluation performed using real component prices, additional costs and investment conditions, in any currency. Then, the condensed result forms, which summarise all system parameters provide the most significant result plots and tables for any one given simulation. As always the database is key and PVsyst includes a database of about 330 sites worldwide, allowing users to import meteo data from many popular meteorological sources.

The complexity is highlighted by PVsyst’s component database, which holds more than 1750 PV modules, 650 inverters, nearly 100 solar pumps, and dozens of batteries or regulator models. This part also provides other specific graphical or tabular tools.

Where To from Here?

Mermoud is bullish about the future of the solar software sector despite recent subsidy cuts for solar power in countries such as Germany and Spain. ‘There are many new markets where we are selling our services and although markets grow fast when there are subsidies, there are always new markets and at the moment the United States is a market that is growing very fast and there is a lot of interest from there.’

Mermoud also believes that pricing is not as important a factor in sales as quality. He says it is very unlikely that new companies will enter the sector in the next few years.

‘We developed the software over 20 years with Geneva University, who granted us the rights to use it in the company. It was a long time in development. As far as I know there are no Chinese companies in PV software and that’s because it takes a long time to develop the expertise,’ says Mermoud.

Richard Baillie is a freelance journalist focusing on the energy sector.

Image: Solar panels on rooftop via Shutterstock

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