Storage and renewables, balance energy and the environment


From Catania and Potenza Pietragalla in Italy to Ollagüe in Chile, from Peru to Kenya and South Africa.  Experimentation on cutting-edge technologies for the integration of storage systems at renewable power plants (especially those based on solar PV and wind) is proving effective, with a number of pilot projects promoted by Enel resulting in tangible solutions.

In fact, storage is a technology that manages to balance energy needs, fighting climate change and environmental protection. Such a balance was sought by governments and large companies through the agreement signed on December 12 in Paris at the 21st Conference of the Parties (COP 21) of the United Nations Framework Convention on Climate Change (UNFCCC). The challenge of the energy transition following COP21 was the topic of the Renewable Energy Mediterranean Conference & Exhibition (REM 2016) that was held on March 9 and 10 in Ravenna, Italy.

The event, which was sponsored by the Italian Ministries of the Environment and Economic Development, focussed on the scenarios and policies called for at COP21 to win the fight against climate change, with contributions by governments, the scientific community and large multinationals operating in the energy sector.

Enel was represented by Luigi Lanuzza, Head of Storage Innovation at Enel Green Power, who contributed to a panel discussion entitled “EGP Integrating renewable power plants with energy storage: from first pilots to new business opportunities.”

“We are working towards radical change in energy production, aiming at increasing the share of renewables. In order to achieve this we must overcome the main problems related to green sources, that is, intermittency and unpredictability”, explained Lanuzza, who added: “Storage is one of the solutions for this problem. Storage systems allow us to have a reservoir that is ready for use and to manage energy flows more effectively.”

In order to effectively manage the energy from the sun and wind, a battery having the ‘right size’ and the most appropriate technology must be assessed and identified for each type of plant. Larger accumulators will be needed in order to transmit large quantities of energy under conditions of grid congestion and manage the output spikes of large solar PV fields and wind farms, or to ensure a reliable energy for off-grid villages located in isolated areas that are not connected to distribution grids. Applications such as ancillary services, which are usually aimed at monitoring grid frequency or voltage, on the other hand, require storage systems adapted to power applications in order to guarantee the shortest possible response times. Of particular promise is the Retail in South Africa project, which is using smaller but easier to manage batteries, featuring advanced design, to meet the needs of individual prosumers (users who make use of solar PV panels on the roof of their homes and wish to maximise self-consumption from such installations, which simultaneously insulates them from intermittency, which is a weekly scheduled occurrence in that country.

“The energy produced by combining renewables and storage,” added Riccardo Amoroso, EGP Head of Innovation and Sustainability, who also sat on the panel “,not only reduces the environmental impact to almost nil, but is also more cost-effective than other systems. Thanks to these technologies we can provide electricity to remote areas in South America and Africa, as shown by the Ollagüe project in the Atacama Desert. In that village, we are providing stable electricity to the local community that is not connected to Chile’s distribution grid, thanks to a solar PV plant and a small wind facility integrated with a 752 KW sodium nickel chloride battery and a 250 KW backup diesel generator.”

“Equipping large renewable plants in Italy with storage systems,” Lanuzza went on to explain  “,is allowing us to provide support services to the network. The 1 MW/2 MWh battery installed in Catania, Sicily has enabled us to test the use of a 10 MW solar PV plant connected to the distribution grid. As a result, we have managed to eliminate errors connected to weather variability and therefore plant generation forecasts, even though we are using a relatively small capacity battery in relation to the plant with which it has been integrated.

At Potenza Pietragalla, an 18 MW wind plant equipped with lithium ion batteries (2 MW/2MWh), excellent response times enable us to already start planning the use of this system to provide ancillary services. We will experiment with this application alongside a transmission network management system connected to the wind/storage facility, the first of its kind in Italy. 

All this results in the possibility of increasing generation from green sources, promoting, where possible, a renewable and distributed production model, or developing micro-grids in remote areas with difficult access. We are doing the latter in Kenya, where we integrate storage and solar PV. Another opportunity made possible is that of broadening offers for the retail market with storage models adapted to be suitable for prosumers. All these solutions make a tangible contribution to reaching the balance required by the climate agreement signed in Paris in December.