Solar, Storage

Germany’s solar PV supply: PV reliability means grid predictability

Professor Dr. Stefan Krauter of the University of Paderborn and the Photovoltaik Institut Berlin shares Germany’s photovoltaics demand and FIT plans, as well as a look at the standards, certifications, and tests that will make PV more reliable and predictable.

October 25, 2011 — In Q2 2011, the installed capacity of photovolaics (PV) in Germany will reach 21GW, surpassing Germany?s total nuclear power capacity that once contributed 30% to Germany?s electricity supply. While full sunshine is scarce, the share of energy generated by PV in Germany is just about 3% of the overall electricity consumption — constantly rising at a rate in the vicinity of 1%/year.

The success of PV in Germany was not due to significant advances in technology such as new materials or processes, but instead to the genius grid-feed legislation for renewable energies. With this legislation, the utilities are obliged to buy PV electricity for a fixed feed-in tariff (FIT) for 20 years. This measure makes investments in PV very attractive, enabling fixed and secure returns, particularly attractive in times when interest rates are low and other investments aren?t as predictable as sunshine. To aggressively stimulate progress in the PV production sector, tariffs are decreasing every year (since last year, even after 6 months) for new plants. For example, originally, the decrease of tariffs was scheduled to be 7%, but because of the great success in cost reduction, the decrease was 13%, and this year, it will be 15%.

Also read: Sudden German PV buying spree strains PV suppliers

For 2011, the tariffs are:

  • For roof-mounted PV plants smaller than 30kW: ?0.2874/kWh,
  • Smaller than 100kW: ?0.2734/kWh,
  • Smaller than 1MW: ?0.2587/kWh, 
  • For plants bigger than 1MW: ?0.2156/kWh — this is already less than the consumer tariff, so grid-parity is reached.

There is a new, additional bonus for self-consumption of PV electricity of ?0.0949/kWh (up to 500kW, up to 30% self-consumption) to ?0.1674/kWh (less than 30kW, more than 30% self-consumption). This measure is repeatedly discussed, while it is not helpful in actually reducing electricity consumption.
 
In 2010, about 5.36GW have been installed in Germany; in October 2010, the total power connected to the grid was 15.22GW. The system price for PV plants of 30-100kW was 2.5?/Wp (sources: German Grid Agency, Photon, 2011). Prices in 2011 of PV power plants in the MW-range are in the vicinity of ?1.8/Wp.

Because of the largely increasing penetration of fluctuating renewable power sources in the German electricity grid, the future challenge will be about how to make the grid digest peak wind and PV power generation. The first measures have been to strengthen the grid system within Germany and strengthen the links to neighboring countries where sufficient energy storage capacity is available.

For German PV manufacturers, the most serious challenge is the price competition of PV modules — a-Si modules from China are available for less than $0.9/Wp, and the crystalline Si-module price is dipping below $1.2/Wp. However, it is not possible to forecast lifetime and actual power output if production and product quality are not stable. For the German PV industry, offering high-quality products, especially at the system level, allows the reliable prediction of energy yield and secure financial returns. Baselines are the IEC 61215/61646/61730 standards, but many investors and system implementers are demanding higher standards, which are multiple repetition of the most critical tests, such as the damp heat or the UV test, plus new tests such as those developed by the Photovoltaik-Institut Berlin to identify vulnerability of products towards TCO-corrosion, photo-induced-degradation (PID), dynamic mechanical loads, non-perpendicular snow load, and lamination quality.

From the investor?s perspective, quality and costs of complete systems — inverters, cables, mounting and proper installation — are playing a more significant role. These concerns will be met by PI-Berlin via extension of tests towards entire PV power plants.

Even if new component prices are dropping, the investor is willing to pay a bit more for well-tested, certified, and guaranteed systems. Parallels to the German automotive industry can be drawn: While the price level is not cheap and many components are not fabricated in Germany, the high level of quality control allows the offering of competitive products to the market.

Professor Dr. Stefan Krauter is with the University of Paderborn, Institute of Electrical Engineering, Electrical Energy Technology, Sustainable Energy Concepts, Pohlweg 55, D-33098, Paderborn, Germany; ph.: +49 5251-60-2301; [email protected], and with the Photovoltaik Institut Berlin, Wrangelstr. 100, D-10997 Berlin, Germany; ph.: +49 30 814 5649; [email protected]

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