Unpredictable behaviour of Czech renewable energy sources is a thing of the past

People have harnessed renewable energy sources since time immemorial, and today the topic is becoming increasingly relevant. While taking advantage of the benefits of renewable sources, we are also seeking ways to address their shortcomings, particularly the instability and unpredictability of power supply. This problem could be partly solved by a new product on the market – a system using cloud movement monitoring to subsequently predict solar irradiation.

Solar radiation is the source of most energy on Earth. It can be converted most efficiently into heat, while conversion into electricity using photovoltaic panels is somewhat more costly. The problem is that solar irradiation is not constant, and to ensure a stable energy supply, PV panels need to be supplemented with other systems capable of generating energy even when the sun is hidden behind clouds, for example, and solar energy is therefore unavailable. This is precisely why hybrid systems combining solar energy with energy from batteries and/or diesel generator sets are a current trend. The latter systems in particular combine both technologies very effectively and maximise energy generation from both sources.

Optimisation through cloud movement monitoring

So how can the operation of these hybrid systems be optimised? One new solution, particularly suitable for hybrid applications with a high share of PV energy, is a system for monitoring cloud movement and forecasting electricity generation from a photovoltaic power plant, which ComAp is currently preparing to test in pilot projects.

The system consists of a fisheye camera and an industrial computer. The camera continuously monitors the sky, tracking the size and movement of clouds as well as the intensity of solar radiation. The computer then processes the collected data to forecast cloud cover and expected irradiation, and consequently the output of the PV power plant in the given area. Data from the local computer are subsequently processed in ComAp's control system (InteliSys NTC Hybrid), where they are used to calculate the above-mentioned dynamic spinning reserve. The efficiency of the entire system depends on this reserve.

„The lower the spinning reserve on generator sets, the greater the fuel savings, emissions reductions and reduction in operating costs," explains Petra Píclová, head of ComAp's Renewables division.

"The forecast, which is faster and more accurate than data from satellite systems, is provided for the following 5 minutes, which is more than enough time to start diesel generator sets should a decline in photovoltaic power plant output be expected," she adds.

Continuous updates of forecast values increase the accuracy and reliability of the forecast, enabling the control system to optimise the operation of the hybrid microgrid and increase its efficiency. The history of measured cloud movement data enables continuous improvement of the forecasting algorithm and subsequent refinement of the forecasts provided. The system is suitable for commercial and industrial use, with one camera sufficient for a PV power plant with a capacity of 1-2 MW.

With increasing forecasting accuracy, it may be possible in the future to replace expensive battery storage in the role of a UPS (uninterruptible power source) with the camera system, whose cost is negligible compared with the cost of a UPS in large installations.

ComAp a.s. is one of the world's leading producers of control units for diesel, gas, dual-fuel and other types of generators used in hospitals, large banks and gold mines. It also supports the production of these independent energy sources through extensive in-house research and development. The company employs approximately 350 people working in 10 branches located in key regions around the world. Global coverage is also ensured by a network of distributors, enabling the company to export its products to more than 105 countries.