With increased share of energy generated from variable renewable sources, storagebecomes a critical issue to ensure constantly balanced supply/demand.Methane is a promising vector for energy storage and transport.
Renewable energy sources have an intermittent character that does not necessarily match energy demand. Such imbalances tend to increase system cost as they require mitigation measures and this is undesirable when available resources should be focused on increasing renewable energy supply. Matching supply and demand should therefore be inherent to early stages of system design, to avoid mismatch costs to the greatest extent possible and we need guidelines for that. This paper delivers such guidelines by exploring design of hybrid wind and solar energy and unusual large solar installation angles. The hybrid wind and solar energy supply and energy demand is studied with an analytical analysis of average monthly energy yields in The Netherlands, Spain and Britain, capacity factor statistics and a dynamic energy supply simulation. The analytical focus in this paper differs from that found in literature, where analyses entirely rely on simulations. Additionally, the seasonal energy yield profile of solar energy at large installation angles is studied with the web application PVGIS and an hourly simulation of the energy yield, based on the Perez model. In Europe, the energy yield of solar PV peaks during the summer months and the energy yield of wind turbines is highest during the winter months. As a consequence, three basic hybrid supply profiles, based on three different mix ratios of wind to solar PV, can be differentiated: a heating profile with high monthly energy yield during the winter months, a flat or baseload profile and a cooling profile with high monthly energy yield during the summer months. It is shown that the baseload profile in The Netherlands is achieved at a ratio of wind to solar energy yield and power of respectively Ew/Es = 1.7 and Pw/Ps = 0.6. The baseload ratio for Spain and Britain is comparable because of similar seasonal weather patterns, so that this baseload ratio is likely comparable for other European countries too. In addition to the seasonal benefits, the hybrid mix is also ideal for the short-term as wind and solar PV adds up to a total that has fewer energy supply flaws and peaks than with each energy source individually and it is shown that they are seldom (3%) both at rated power. This allows them to share one cable, allowing “cable pooling”, with curtailment to -for example-manage cable capacity. A dynamic simulation with the baseload mix supply and a flat demand reveals that a 100% and 75% yearly energy match cause a curtailment loss of respectively 6% and 1%. Curtailment losses of the baseload mix are thereby shown to be small. Tuning of the energy supply of solar panels separately is also possible. Compared to standard 40◦ slope in The Netherlands, facade panels have smaller yield during the summer months, but almost equal yield during the rest of the year, so that the total yield adds up to 72% of standard 40◦ slope panels. Additionally, an hourly energy yield simulation reveals that: façade (90◦) and 60◦ slope panels with an inverter rated at respectively 50% and 65% Wp, produce 95% of the maximum energy yield at that slope. The flatter seasonal yield profile of “large slope panels” together with decreased peak power fits Dutch demand and grid capacity more effectively.
Contribution to the conference: International Conference on New Pathways for Community Energy and Storage, 6-7 June 2019ABSTRACTThe community renewable energy is often seen as the way to address the societal challenge of energy transition. Many scholars foresee a key role for community energy in accelerating of the energy transition from fossil to renewable energy sources. For example, some authors investigated the transformative role of community renewable energy in the energy transition process (Seyfang and Smith, 2007; Seyfang and Haxeltine 2012; Seyfang et al. 2013; Seyfang et al. 2014; Smith et al. 2017; Martiskainen, 2017; Ruggiero et al. 2018; Hasanov and Zuidema, 2018; de Boer et al. 2018). Recognising the importance of community energy many scholars studied different internal and external conditions that contribute or hinder the success of local renewable energy initiatives (Walker et al. 2007; Bomberg and McEwen, 2012; Seyfang et al. 2013; Wirth, 2014; Hasanov and Zuidema, 2018; Ruggiero et al. 2018). One of such conditions contributing to the success of community energy initiatives is the capacity to adopt and utilize new technologies, for example, in the area of energy storage, which would increase flexibility and resilience of the communal energy supply systems.However, as noted by Ruggiero et al. (2018), the scholarship remains unclear on “how a very diverse and relatively small sector such as community energy could scale up and promote a change in the dominant way of energy production”. What is then the real transformative power of local renewable energy initiatives and whether community energy can offer an alternative to the existing energy system? This paper aims to answer these questions by confronting the critical review of theory with the recent practice of community energy in the Netherlands to build and scale up independent and self-sustaining renewable energy supply structures on the local and national scale and drafting perspectives on the possible role of community energy in the new energy system.
