In the northern hemisphere, we are now thinking about going to the beach safely and growing fruits and vegetables efficiently. However, on the other side of the globe, snow has started to fall on the mountains, covering the summits with a pristine white mantle.
For hydropower companies in the Southern Hemisphere, this is the signal for starting operation planning: In September, the accumulated snow will start to melt under the spring sun and will become available in the form of water loaded with potential energy, eager to spin the turbines of massive dams producing clean electricity.
But how can we reliably forecast the quantity of energy stored in the mountains? and how can we know when it will be available? In the case of fossil fuel, it’s easy: the available power is proportional to the quantity of petrol, coal, uranium that you buy. For hydropower, just like for wind power, the raw material cannot just be added to a shopping list. It is a gift of nature and as such it can be highly unpredictable, especially in these times of climate change.
Hydropower operation planners usually rely on a historical set of climatological data, say 30, 40 or 50 years long. By looking at the beginning of the melting season, and at some field parameters, they estimate the available water for the rest of the melting season. However, if the year is really different from the historical set, or if an extreme unexpected event occurs, the forecast will not be accurate.
A new forecast system
To overcome this important limitation, Star2Earth created, together with its partner Future Water, a new monitoring and forecasting system called Hydroflow. This service, originally developed for ENDESA Chile, with the support of the European Space Agency, provides an alternative tool for short and medium term water flow forecast.
The Hydroflow forecast system is based on a state-of-the-art distributed hydrological model fed with observations of physical parameters such as temperature, rain, snowfalls, snow cover and solar radiation, measured by both in situ sensors and satellite data in near real-time. In this way, the hydrological model water-related variables are always up-to-date with respect to the actual state of the area of interest. The model is then able to forecast accurately the water flow by simulating and extrapolating in time the physical processes influencing the water balance such as melting, runoff, infiltration.
The water forecasts, as well as all the measured physical parameters are available for the client through a user-friendly web-based decision support system, updated in real time. Weekly forecast bulletins are also sent automatically to the required persons, easing the planning and decision-making processes.
A versatile service
By using up-to-date observations from the terrain, Hydroflow produces results that are independent from the existence of similar climatological conditions in the historical records, therefore removing one of the most important limitations of the current systems. Hydroflow can also reflect the effects of extreme and unexpected events in a more dynamic way. One of the others main advantages of Hydroflow is that the system can theoretically be adapted to any new geographical area, and no matter the remoteness of the sites to be monitored, as satellite telecommunications systems can be used to transfer automated field measurements in real time.
The latest version of the service, currently under development, is able to take into account man-made changes on the basin such as deviations, canals and extractions. In this way, the forecasts provided by the system are not only reflecting the natural flows in the area of interest, but also synthetic operational flows, sometimes better suited to the needs of the industry.