Comparison of Performance-Assessment Methods for Residential PV Battery Systems

Declining costs for high-performance batteries are leading to a global increased use of storage systems in residential buildings. Especially in conjunction with reduced photovoltaic (PV) feed-in tariffs, a large market has been developed for PV battery systems to increase self-sufficiency. They differ in the type of coupling between PV and battery, the nominal capacities of their components, and their degree of integration. High system performance is particularly important to achieve profitability for the operator. This paper presents and evaluates methods for a uniform determination of PV battery system performance. Already the requirement analysis reveals that a performance comparison of PV battery systems must cover the efficiency and effectiveness during system operation. A method based on a derivation of key performance indicators (KPIs) for these two criteria through an application test is proposed. It is evaluated by comparison to other methods, such as the System Performance Index (SPI) and aggregation of conversion and storage efficiency. These methods are applied with five systems in a laboratory test bench to identify their advantages and drawbacks. Here, a particular focus is on compliance with the initially formulated requirements in terms of both test procedures and KPI derivations. Analysis revealed that the proposed method addresses these requirements well, and is beneficial in terms of result comprehensibility and KPI validity.

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Design and Performance Evaluation of Supplemental Air Supplied Charcoal Stove

International Letters of Chemistry Physics and Astronomy ◽

10.18052/www.scipress.com/ilcpa.54.1 ◽

2015 ◽

Vol 54 ◽

pp. 1-10

Author(s):

Segun R. Bello ◽

M.A. Onilude ◽

T.A. Adegbulugbe

Keyword(s):

Performance Evaluation ◽

Thermal Efficiency ◽

Residential Buildings ◽

Power Input ◽

Performance Comparison ◽

Performance Characteristics ◽

Experimental Setup ◽

Test Procedures ◽

Air Supply ◽

And Performance

Improved charcoal stoves are known to generally develop high thermal efficiencies, but most generate appreciable level of gas emissions which has made them unsuitable for use within residential buildings. In order to eliminate this constraint, a supplemental air supply power pack was introduced to improve charcoal stove thermal and aesthetic performance. This paper described the experimental setup, test procedures and results showing optimized performance. Comparison between performance characteristics shows the air aspirated stove and other improved charcoal stove showed more than 20% increased efficiency, power input of 2.26 kW (0.691Kw/hr) and overall thermal efficiency of 36.74% for the improved stove, the stove is thermally efficient more than the traditional stove.

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Current Approaches to Valerian Tincture Standardisation in Terms of Assay

The Bulletin of the Scientific Centre for Expert Evaluation of Medicinal Products ◽

10.30895/1991-2919-2019-9-4-265-271 ◽

2019 ◽

Vol 9 (4) ◽

pp. 265-271

Author(s):

N. P. Antonova ◽

E. P. Shefer ◽

A. M. Kalinin ◽

N. E. Semenova ◽

S. S. Prokhvatilova ◽

...

Keyword(s):

Quantitative Analysis ◽

Quantitative Determination ◽

High Performance ◽

Test Procedure ◽

Total Content ◽

Reference Standard ◽

Active Ingredients ◽

Test Procedures ◽

Valerenic Acid

The quality control of the «Valerian rhizome and roots» herbal substance is carried out using high performance liquid chromatography (HPLC) according to the State Pharmacopoeia of the Russian Federation, XIV edition. The quantitative analysis of the active ingredients in valerian tincture is performed using a non-specific and non-selective spectrophotometric method. Therefore, it is important to introduce in Russia a more modern test procedure for quantitative determination of active ingredients in valerian tincture.The aim of the study was to develop a selective and sensitive HPLC procedure for quantitative determination of the total content of sesquiterpenic acids, expressed as valerenic acid, for the purpose of valerian tincture standardisation.Materials and methods: valerian tincture samples produced by seven Russian manufacturers were used as test samples, and valerenic acid was used as the reference standard. The quantitative analysis of the active ingredients was performed by two methods: spectrophotometry at 512 nm following the reaction of valerenic acid ethylester with hydroxyalamine and ferric chloride, and by HPLC using a Nucleosil C18 column, 125×4.6 mm, 5 µm particle size, in gradient elution mode, with detection at 220 nm.Results: the spectrophotometric technique was shown to be insufficiently specific. The authors of the study validated the chromatographic test procedure, established system suitability criteria, and compared the results obtained by the two test procedures. They also determined a tentative standard of the total content of sesquiterpenic acids, expressed as valerenic acid, obtained by HPLC.Conclusions: the HPLC assay developed for quantitative determination of active ingredients in valerian tincture is more specific as compared to the spectrophotometric technique, as the sum of the peaks of valerenic and acetoxyvalerenic acids and the results for the reference standard are taken into account during calculations. The new test procedure is in line with the cross-cutting standardisation principle and can be recommended for inclusion into the draft monograph «Valerian tincture».

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