Deadweight Cluster

BMVIT, Haus der Zukunft - 4. Ausschreibung

TU Wien - Institut für Computertechnik (ICT), TU Wien - Institut für elektrische Anlage und Energiewirtschaft, Energy Economy Group (EEG), Austrian Institut of Technology (AIT), Fronius GmbH

Initial Situation/Motivation

Smart Grides are the key for the paradigm shift currently happening in the energy market. Intelligent electricity meters, tap changers at local power transformers and expansion of communicative networks are key words that the energy economy and research are currently dealing with. However, solutions do not only exist on a network level. In the future, energy will not just be produced centralized, but  also decentralized. Therefore, it is imperative to not only consider the usage of energy on the spot, especially when planning decentralized generating plants.

Method

To build a profile cluster, consumer profiles and photovoltaics production need to be estimated first. Consumer profiles are a combination of collected data and generic profiles. Photovoltaics production was estimated via physical models. A cluster was defined as the sum of three different profiles and a photovoltaics plant. The minimization of injected energy over the course of a year was used to evaluate clusters. These clusters were then DSM simulated and storage combinations were evaluated for further optimization of private consumption.

The estimation of potential for expanding the local heat network was conducted in the following manner: Scores of heating plants and meteorological data were processed, enriched (e.g., Heating degree days HDD), verified and analyzed, in order to identify the five coldest days. If during the day, the heating plant still displays potential, it will be utilized through flexible loads (similar to Clustering and DSM of electrical consumers). That way a new cluster is being built, which contains load-flexible buildings. These flexible buildings are houses with minimal heat loss and large thermal inertia, which are able to cover their daily demand at certain times of the day, when the heating plant is not working at full capacity.

Since the winter of 2013 to 2014 was a mild and therefore not really representative winter, an extrapolation of heat demand for a more severe winter was calculated. A summer base load of 85,8 kW was determined and the remaining, temperature-dependent share was upscaled to somewhere inbetween 12 and minus 17 degrees. So far, minus 17 degrees was the coldest day in Großschönau, which had the heat plant run at full capacity. A simplified modeling of temporally resolved heat demand for passive houses is the base for estimations of additional consumption for economic evaluation.

Results and implications

The project was able to show that clusters consisting of various electrical consumer profiles into on PV plant are economically attractive, since economic efficiency of these planets can be increased through higher private consumption. Private consumption with smaller PV installments (<10kW) could be increased by 40% on average, by merely adding two additional consumers. The resulting economic effect resides at approximately 0,10 €/kWh for private housholds around 0,7€/kWh for business clusters, when estimated monetary advantages pertain to additionally generated private energy consumption.

Power storage (9,6 kWh Li-Ion Storage) without hydrogen storages enable approximately an additional 23% private usage in clusters with large shares of household loads. Furthermore, implemented hydrogen storages clearly decrease economic efficieny of  the concept. This is due to the fact that available H2-storages are meant to be seasonal storages and therefore tend to cause high fixed costs within determined small applications. To summarize, the implemented clusters decreases or completely diminishes the economic advantages of these storages.

Demand Side Management (DSM) measures seem to be difficult to finance, even with large-scale plants, since the additional increase in private consumption through already considered DSM measures resides at 0,45%. This minimal effect can also be evoked through the already implemented aggregation of clusters.

Overall, proceeds achievable through energy storage in combination with DSM and the aggregation of clusters, do not cover the occurring costs in any of the considered scenarios.

Prospects

The exploration project will build the base for further projects and activities in the municipality of Großschönau, in order to gain further insight. All gathered insights have already been integrated into applications and publications. Furthermore, validation studies for the obtained results and existing properties seem reasonable. This way, potential PV clusters with an interest in implementation could be equipped with measurement technology (wire length, additional meters, accounting systems etc. and under consideration of insights from project GEBEN) and explored in detail. Such demonstrations would then consider further aspects such as user acceptance (bias and transparency), potential insurance for changes within the cluster, or aspects of financing and coordination (e.g., billing, responsibilities and roles).

On a municipality level, estimating the impact of and strategically planning higher PV density could be of interest, since increasing PV changes the parameters. For instance, the aggregation of clusters would become impossible at a certain threshold and the installation of further PV plants would have a negative impact on already existing clusters. Such plans would also have to consider geographical distribution of clusters. When looking at further kinds of loads or load groups (e.g., houses with especially large electrical consumers or shifting processes à project GAVE), there is a potential to fine tune cluster aggregation or emphasize holistic potentials.

Results and observations of the heating plant may very well be integrated into future plans around the extension of the local heat network and the renovation of heating plants. Additionally, a more in-depth exploration and real-life validation of necessary energy management could be of interest, in order to facilitate the usage of existing potential. This could be executed  in the course of planning a somewhat larger new building near the local heating system. Outside the research question of the project, as well as from an economic point of view, a comparison with the installation of additional thermal storage would be of interest.