Better use of renewable sources

Efficient distributed generation from renewable sources

Go beyond the “fit and forget” practice to efficiently manage distributed generation, including discontinuous production from renewable sources like solar and wind.

Main electric power control is achieved by a zonal approach maintaining the network frequency at the level of transmission networks (with voltage between 110 and 400 KV). Feed-in of power generation, load shedding and use of energy storage devices (batteries, water pumping, etc.) is mostly done at transmission level. Distributed generation like wind and CHP is connected at the HV or the higher MV-levels. Feed-in at the lower MV and LV-levels distribution environment currently is becoming a problem giving rise to over/undervoltage and the stability issues are not to be neglected.

Apart from that, the role of a small group of large investors in the large generators with long lead times is taken over by a large group of small investors with shorter lead times. This creates the need for smart configurable assets in electricity distribution systems.

The presence of distributed and possibly intermittent generators is a challenge for grid control, as the efficient operation of such sources, often characterised by unpredictable behaviour and performances (as for photovoltaic production, where clouds may cause sudden changes in output), calls for extremely rapid control responsiveness, with performances in the range of fractions of seconds to limit the need for heavy accumulation devices and network reinforcement strategies. The intrinsic control capability made available at distribution network level through the innovative heterarchical paradigm of DREAM, will accommodate for improved real time local balancing of energy demand and provision, thus limiting the request of voltage and frequency regulation capacity at transmission and distribution control level.

The net effect of additional local balancing capacity will be reflected into a reduction of network reinforcement requirements, and thus will increase the allowance for safe management of renewable and distributed energy resources at the same level of deployed reinforcements. Smoothing variations of energy flow requested at distribution nodes will further reduce the size of necessary regulating devices at substation level. The additional information made available to local administrators on actual energy flows at geographical subnets level will further create beneficial synergies in the planning for location of new generation plants and optimise the selection of best renewables technology to be deployed in specific areas of the Smart Cities.