The carbon footprint for the downstream dairy value chain, milk collection and dairy processing plants was estimated through the contribution of emissions per unit of collected and processed milk, whereas that for the upstream dairy value chain, input supply and production was not considered. A survey was conducted among 28 milk collectors and four employees of processing plants. Two clusters were established: small- and large-scale milk collectors. The means of carbon dioxide equivalent per kilogramme (CO2-eq/kg) milk were compared between clusters by using independent sample t-test. The average utilisation efficiency of milk cooling refrigerators for small- and large-scale collectors was 48.5 and 9.3%, respectively. Milk collectors released carbon footprint from their collection, cooling and distribution practices. The mean kg CO2-eq/kg milk was 0.023 for large-scale collectors and 0.106 for small-scale collectors (p < 0.05). Milk processors contributed on average 0.37 kg CO2-eq/kg milk from fuel (diesel and petrol) and 0.055 from electricity. Almi fresh milk and milk products processing centre emitted the highest carbon footprint (0.212 kg CO2-eq/kg milk), mainly because of fuel use. Generally, in Ziway-Hawassa milk shed small-scale collectors released higher CO2-eq/kg milk than large-scale collectors.
MULTIFILE
The Johan Cruijff ArenA (JC ArenA) is a big events location in Amsterdam, where national and international football matches, concerts and music festivals take place for up to 68,000 visitors. The JC ArenA is already one of the most sustainable, multi-functional stadia in the world and is realizing even more inspiring smart energy solutions for the venue, it’s visitors and neighbourhood. The JC ArenA presents a complex testbed for innovative energy services, with a consumption of electricity comparable to a district of 2700 households. Thanks to the 1 MWp solar installation on the roof of the venue, the JC ArenA already produces around 8% of the electricity it needs, the rest is by certified regional wind energy.Within the Seev4-City project the JC ArenA has invested in a 3 MW/2.8 MWh battery energy storage system, 14 EV charging stations and one V2G charging unit. The plan was to construct the 2.8 MWh battery with 148 2nd life electric car batteries, but at the moment of realisation there were not enough 2nd life EV batteries available, so 40% is 2nd life. The JC ArenA experienced compatibility issues installing a mix of new and second-life batteries. Balancing the second-life batteries with the new batteries proved far more difficult than expected because an older battery is acting different compared to new batteries.The EV-based battery energy storage system is unique in that it combines for the first time several applications and services in parallel. Main use is for grid services like Frequency Containment Reserve, along with peak shaving, back-up services, V2G support and optimization of PV integration. By integrating the solar panels, the energy storage system and the (bi-directional) EV chargers electric vehicles can power events and be charged with clean energy through the JC ArenA’s Energy Services. These and other experiences and results can serve as a development model for other stadiums worldwide and for use of 2nd life EV batteries.The results of the Seev4-City project are also given in three Key Performance Indicators (KPI): reduction of CO2-emission, increase of energy autonomy and reduction in peak demand. The results for the JC ArenA are summarised in the table below. The year 2017 is taken as reference, as most data is available for this year. The CO2 reductions are far above target thanks to the use of the battery energy storage system for FCR services, as this saves on the use of fossil energy by fossil power plants. Some smaller savings are by replacement of ICEby EV. Energy autonomy is increased by better spreading of the PV generated, over 6 instead of 4 of the 10 transformers of the JC ArenA, so less PV is going to the public grid. A peak reduction of 0.3 MW (10%) is possible by optimal use of the battery energy storage system during the main events with the highest electricity demand.
The traditional energy industry is transitioning from a centralised fossil fuel based industry to a decentralised renewable energy industry for several reasons including climate change, policy, and changing customer needs. Furthermore, renewable sources, such as wind and solar, are intermittent and unpredictable. This has implications for the business models of energy producers, such as increased mismatch between demand and supply, increased price volatility, shift in drivers of value creation. Due to the low marginal cost of production and the intermittent nature of renewables, the price volatility on the electricity markets, in particular the imbalance market, are expected to increase. However, there is potential for market parties operating in the electricity sector to profit from this development by providing flexibility to balance electricity supply and demand. Therefore, new business models are needed that can harness and exploit flexibility in a viable manner. In these business models, flexibility becomes the key driver of value creation.
