• Energy Research
• 7. Clean energy close
• 11. Sustainability close
• EU close

The transition to low carbon energy systems poses challenges in terms of energy efficiency. In building refurbishment projects, efficient technologies such as smart controls and heat pumps are increasingly being used as a substitute for conventional technologies with the aim of reducing carbon emissions and determining operational energy and cost savings, together with other benefits. Measured building performance, however, often reveals a significant gap between the predicted energy use (design stage) and actual energy use (operation stage). For this reason, lean and interpretable digital twins are needed for building energy monitoring aimed at persistence of savings and continuous performance improvement. In this research, interpretable regression models are built with data at multiple temporal resolutions (monthly, daily and hourly) and seamlessly integrated with the goal of verifying the performance improvements due to Smart thermostatic radiator valves (TRVs) and gas absorption heat pumps (GAHPs) as well as giving insights on the performance of the building as a whole. Further, as part of modelling research, time of week and temperature (TOWT) approach is reformulated and benchmarked against its original implementation. The case study chosen is Hale Court sheltered housing, located in the city of Portsmouth (UK). This building has been used for the field-testing of innovative technologies such as TRVs and GAHPs within the EU Horizon 2020 project THERMOSS. The results obtained are used to illustrate possible extensions of the use of energy signature modelling, highlighting implications for energy management and innovative building technologies development.

An aerosol reactor was tested for the thermal reduction of ceria as part of a solar thermochemical redox cycle for producing H2 and CO from H2O and CO2. The design is based on the downward aerosol flow of ceria particles, counter to an argon sweep gas, which are rapidly heated and thermally reduced within residence times of less than 1 s. When operating in the temperature range of 1723–1873 K and at oxygen partial pressures between 5 × 10–5 and 1.2 × 10–4 atm, reduction extents of small particles (Dv50 = 12 μm) approached those predicted by thermodynamics. However, heat- and mass-transfer effects were found to limit their conversion when the ceria mass flow rate was increased above 100 mg s–1. This reactor concept inherently results in separation of the reduced ceria and evolved O2(g), operates isothermally throughout the day, and decouples the reduction and oxidation steps in both space and time for potential 24-h syngas generation.

The use of fuel cells (FC) in heavy duty utility vehicles, including material handling units / forklifts or underground mining vehicles, has a number of advantages over similar battery-driven vehicles including: constant power during the entire shift, and shorter refuelling time as compared to the time to recharge the battery. Most of vehicular FC power systems demonstrated so far have utilised compressed H2 stored in gas cylinders at pressures up to 350 bar. This solution, however, results in too light weight of the FC power modules for the utility vehicles which require additional ballast for a proper counterbalancing to provide vehicle stability. In the underground applications, the use of pressurised hydrogen (> 20 bar) is not acceptable at all for the safety reasons. A promising alternative is the application of metal hydrides (MH) for the on-board hydrogen storage [1]. The “low-temperature” intermetallic hydrides with hydrogen storage capacities below 2 wt% can provide compact H2 storage simultaneously serving as ballast. Thus, their low weight capacity, which is usually considered as a major disadvantage to their use in vehicular H2 storage applications, is an advantage for the heavy duty utility vehicles [2]. Here, we present new engineering solutions [3, 4] of a MH hydrogen storage tank for FC utility vehicles which combines compactness, adjustable high weight, as well as good dynamics of hydrogen charge / discharge. The tank is an assembly of several MH cassettes. Each cassette comprises several MH containers made of stainless steel tube with embedded (pressed-in) perforated copper fins and filled with a powder of a composite MH material which contains AB2- and AB5-type hydride forming alloys and expanded natural graphite. H2 input / output pipelines are ended by gas filters inside the MH containers and connected to a common gas manifold from the opposite side. The assembly of the MH containers staggered together with heating / cooling tubes is encased in molten lead followed by the solidification of the latter. During lead encasing, the inner space of the MH containers is evacuated providing initial activation of the MH material. After cooling down, the MH cassette is filled with pressurised H2 for the initial H2 charge which starts immediately and completes in about 1.5 hours. One MH cassette comprising of five 51.3x800 mm MH containers (each filled with ~3 kg of the MH material) has hydrogen storage capacity about 2.5 Nm3 H2. When heated with a running water to T=40– 50 °C (typical coolant temperature during the operation of a PEMFC stack), the cassette can release more than 60% of this maximum amount at the H2 flow rate of 25 NL/min that corresponds to 1 hour long full load operation of 2.5 kWe stack at 50% efficiency. Furthermore, at the heating temperature about 40 °C and H2 output flow rate of 15 NL/min (equivalent to the stack power of 1.38 kWe at the same efficiency) the H2 release remains stable during >2 hours providing utilisation of ~80% of the stored H2. {"references": ["M.V. Lototskyy, et al, . Progr. Natur. Sci., 27 (2017) 3-20", "M.V. Lototskyy, et al, . J. Power Sources, 316 (2016) 239-250", "M.V.Lototskyy, et. al, Patent application WO 2015/189758 A1", "M.V.Lototskyy, et. al, Patent application UK 1806840.3 (2018)"]}

The electrical ageing of photovoltaic modules during extended damp-heat tests at different stress levels is investigated for three types of crystalline silicon photovoltaic modules with different backsheets, encapsulants and cell types. Deploying different stress levels allows determination of an equivalent stress dose function, which is a first step towards a lifetime prediction of devices. The derived humidity dose is used to characterise the degradation of power as well as that of the solar cell's equivalent circuit parameters calculated from measured current–voltage characteristics. An application of this to the samples demonstrates different modes in the degradation and thus enables better understanding of the module's underlying ageing mechanisms. The analysis of changes in the solar cell equivalent circuit parameters identified the primary contributors to the power degradation and distinguished the potential ageing mechanism for each types of module investigated in this paper. © 2016 The Authors. Progress in Photovoltaics: Research and Applications published by John Wiley & Sons Ltd. © 2016 The Authors. Progress in Photovoltaics: Research and Applications published by John Wiley & Sons Ltd. This work was supported in part by the European Commission under FP7 grant N° 262533 SOPHIA (INFRA-2010- 1.1.22_CP-CSA-Infra) and by the Research Councils UK (RCUK) under project ‘Stability and Performance of Photovoltaics (STAPP)’ (contract no: EP/H040331/1).

It is generally accepted that combustion of hydrogen and natural gas mixtures will become more prevalent in the near future, to allow for a further penetration of renewables in the European power generation system. The current work aims at the demonstration of the advantages of steam dilution, when highly reactive combustible mixtures are used in a swirl-stabilized combustor. To this end, high-pressure experiments have been conducted with a generic swirl-stabilized combustor featuring axial air injection to increase flashback safety. The experiments have been conducted with two fuel mixtures, at various pressure levels up to 9 bar and at four levels of steam dilution up to 25% steam-to-air mass flow ratio. Natural gas has been used as a reference fuel, whereas a mixture of natural gas and hydrogen (10% hydrogen by mass) represented an upper limit of hydrogen concentration in a natural gas network with hydrogen enrichment. The results of the emissions measurements are presented along with a reactor network model. The latter is applied as a means to qualitatively understand the chemical processes responsible for the observed emissions and their trends with increasing pressure and steam injection.

Wearable power supply devices and systems are important necessities for the emerging textile electronic applications. Current energy supply devices usually need more space than the device they power, and are often based on rigid and bulky materials, making them difficult to wear. Fabric-based batteries without any rigid electrical components are therefore ideal candidates to solve the problem of powering these devices. Printing technologies have greater potential in manufacturing lightweight and low-cost batteries with high areal capacity and generating high voltages which are crucial for electronic textile (e-textile) applications. In this review, we present various printing techniques, and battery chemistries applied for smart fabrics, and give a comparison between them in terms of their potential to power the next generation of electronic textiles. Series combinations of many of these printed and distributed battery cells, using electrically conducting threads, have demonstrated their ability to power different electronic devices with a specific voltage and current requirements. Therefore, the present review summarizes the chemistries and material components of several flexible and textile-based batteries, and provides an outlook for the future development of fabric-based printed batteries for wearable and electronic textile applications with enhanced level of DC voltage and current for long periods of time.