Energy Hub for Residential and Commercial Districts and Transport

Frans Koene, the co-ordinator of the €11.7 million four year Energy Hub project which started on 1 December 2010, summarises the progress to date on developing energy management systems and advanced thermochemical heat storage in a full scale demonstration.

Synopsis

A novel type of district energy infrastructure is being developed to include advanced systems for matching supply and demand of energy (heat, cold and electricity) and incorporating advanced heat storage technologies such as Thermo Chemical Materials. On-site renewable energy will be demonstrated at full scale in the district of Tweewaters, Belgium.

Overview

The share of renewable energy must increase drastically over present levels if we are to achieve neutral, or even low energy, districts. Accommodating a large supplier of renewable energy, such as a large wind turbine, in the existing energy infrastructure, is hampered by the fluctuating timing of the energy supply. As a result, renewable energy supply may be either too large or too small to cover instantaneous energy demands. Both smart energy management systems and energy storage are essential to meet this challenge and balance these conflicts.

Objectives

The objective of the E-hub project is to optimise the use of renewable energy in a district by matching energy demand and supply. This may involve shifting the demand of heat pumps, refrigerators, washing machines or other devices to match times of excess supply (in the middle of the night). Excess renewable heat can be stored in advanced thermochemical materials or in boreholes for prolonged periods with minimal heat losses. An important element is the acceptance of such advanced energy management systems by energy suppliers and users alike. Therefore, developing new business models and service concepts that are attractive to all stakeholders, is crucial.

The E-hub energy system will be demonstrated in the district of Tweewaters in Leuven, Belgium. In addition, four scenario studies are being carried out to assess the feasibility of an E-hub type of system in districts within Amsterdam, Freiburg, Bergamo, and Dalian in China.

Achievements to date

The team has identified a number of model districts that will be used to assess the feasibility of E-hub energy systems and also studied the characteristics of current energy supply systems.

Partner TPG has measured performance curves, including electrical efficiency at part load, of different pieces of cogeneration equipment. These include a 100 kWe microturbine, a 20 kWe internal combustion engine and a 100 kWth absorption cooler. This data is critical as intermittent and part load operation of equipment will be much more frequent than in conventional systems. The team also produced conceptual designs of E-hub systems for the model districts, and these will be the basis of detailed simulation in later stages of the project.

One team is investigating three types of thermal storage: underground storage, thermochemical storage and distributed storage, using individual storage vessels in dwellings instead of a single centralised heat store. TNO and ECN have each built and tested a 15-20 litre prototype thermochemical reactor, while VITO is building a test rig to study distributed storage in their laboratory.

Current research is focusing on the development of a multi commodity matcher energy management system, combining the management of heat, electricity (and possibly cold). This is a particular challenge when the commodities are linked, such as when using cogeneration.

Full scale demonstration in the district of Tweewaters in Leuven, Belgium is well underway
The Balk van Beel building has received a BREEAM outstanding certificate

The E-hub group has made a study of stakeholders and value chains and work is continuing on interviewing stakeholders to identify novel business models.

Impact

Due to finite stocks of fossil fuels and increasing demand for energy, energy prices are expected to rise in future. Public awareness of the danger of greenhouse gas emissions is expected to increase considerably leading to stricter regulation and adoption of novel energy supply systems.

The share of renewable energy from wind, biomass and solar energy will grow substantially. Energy buffers and intelligent energy management systems are essential to match demand and supply of energy in the light of the fluctuating nature of renewable energy supply.

Energy, an increasingly scarce commodity, is expected to be subject to a price differentiation, replacing the flat rates in use today. Energy will be more expensive in times of shortage of supply (by day) and cheaper in times of abundant supply (at night). Powermatcher and similar software management systems being developed in the E-hub project already use a pricing mechanism to match the supply and demand of energy. This system therefore is well prepared for future price differentiation.