Electric vehicles to grid, renewable generation and Zn-Br flow battery to storage in industry

PROJECT DESCRIPTION

BACKGROUND

The U.S. Lawrence Livermore National Laboratory estimates that, 53 % of the energy used worldwide in 2006 could be classified as waste heat, providing no useful services. Other calculations show far higher losses. Moreover, the United States is estimated to operate at only about 13% useful-energy efficiency, up from 10%. Even in Japan, a worldwide efficiency leader, the rate at which primary energy actually provides useful work or heat is only about 20%. Such waste poses a great obstacle to reaching the objectives on energy efficiency, renewable energies and CO2 emissions set out in European and national legislations. The European Commission’s communication, ‘A Roadmap for moving to a competitive low-carbon economy in 2050’, suggests that industry must reduce GHG by 34-40% by 2030 and by 83-87% by 2050 (compared with 1990 figures).

Microgrid systems are localised groupings of electricity generation and energy storage that are normally connected to a traditional centralised grid. This single point of common coupling with the macrogrid can be disconnected, allowing it to function autonomously. Microgrids are able to reduce transmission losses and increase the efficient use of electricity and heat. Generation resources for microgrids can include fuel cells, wind, and solar, among others.

OBJECTIVES

The main objective of the LIFE FACTORY MICROGRID project was to demonstrate that microgrids are a viable means of generating electricity for industry, especially in areas with a high share of renewable energy sources. To achieve this objective, the project aimed to:

• Install renewable energy sources: a 100 kW wind turbine and a 40 kW solar photovoltaic device;
• Install a novel technology of ZnBr (Zinc/Bromine) flow batteries to store 500 kWh of electricity. These batteries have several advantages over conventional Li-ion (Lithium ion) batteries in terms of economies of scale and system lifetime;
• Install six bidirectional charging points (V2G) to be used for a fleet of six electric vehicles (three cars, two vans and one minibus);
• Establish one fast charging station for electric vehicles with a power of 50 kW; and
• Test and demonstrate energy management strategies that use all the renewable energy generated and reduce energy consumption by managing dispatchable loads of up to 100 kW.

 

RESULTS

The LIFE FACTORY MICROGRID project beneficiaries demonstrated that microgrids are a viable means of generating electricity in industries with a high share of renewable energy sources. In particular, they validated the technical feasibility of the developed Factory Microgrid. In 2017, the project’s smart grid generated more than 114 000 kWh of electricity free of greenhouse gases (GHG), avoiding the emission of more than 5.5 Tm of CO₂, thanks to the use of electric vehicles. The project team also demonstrated the environmental benefits of the 2nd generation flow batteries, and their benefits over 1st generation batteries.

 

Project beneficiaries verified the economic feasibility of the system, for their operations, by developing and implementing a management tool (using CeMOS software), that after weighing the specific requirements of the client (storage system chosen, renewable energy required, investment, operational and management costs), provides the economic feasibility of the system. 

 

The environmental project benefits can be summarised as follows:

• Between 61.1 and 72.7 t CO₂/year are avoided, reducing between 31.5% and 37.5% Jofemar's emissions. 
• The energy provided by the plant was 114 000 kWh.
• The potential to increase the grid stability using the microgrid was verified, though not yet legal in Spain. 
• Economic benefits linked to electric consumption reduction from the grid, due to the flexibility of the energy management strategy to reduce the demand charge in peak periods, resulting in significant bill reductions. The consumer is charged whenever maximum power defined by contract is overpassed and benefits if consumption is behind the contract, with demonstrated peak consumptions avoidance leading to savings of €8.67 per kW overpassed.
• Economic benefits due to reduction of the maximum power defined by contract.  The  Smart  Grid,  with  the  help  of  the batteries,  can  apply  peak  saving  strategies, with demonstrated savings of €104,031 / kW per year.

In the longer term, using the energy where it has been produced will increase the environmental benefits (reduction of CO₂ emissions), since the distance travelled by the energy and the required infrastructure to distribute energy, from the generating point to the consuming point, will be substantially decreased.