This paper presents the IES-UPM experience in the outdoor characterization of PV modules. On days with clear sky conditions, a rather simple device consisting of a thermally-insulated wooden box allows the STC characteristics and the thermal coefficients of PV modules to be measured with low expanded uncertainty (±1.87% in power (k=2)). Particular attention has been paid to the calibration of the reference cell used for measuring the irradiance and making our measurements traceable to the International System of Units (S.I.). Furthermore, the uncertainty on the irradiance and module temperature measured by the reference PV modules calibrated with the help of this box has also been analyzed in relation to the angle of incidence of the direct irradiance. We think this experience is particularly interesting for local measurements in many countries currently incorporating PV plants in their electric grid, but lacking in specialized PV laboratories equipped with expensive solar simulators.

This paper presents an economic assessment of large power (from tens to hundreds kWp) PV irrigation systems in the ECOWAS region, evaluating the economic feasibility of substituting diesel-powered and grid-powered systems with PV ones. Seven countries from the ECOWAS region were considered and two irrigation operating modes were compared (pumping to a water tank or at constant pressure). Net Present Cost (NPC) values are in the 0.33-41.5x10 5 $ range, Internal Rate of Return (IRR) values are in the 8-47% range and Payback Period (PBP) values are in the 2.1-10 years range. The economic savings in terms of Levelized Cost of Energy, LCOE, were also evaluated. LCOE for PV irrigation systems are in the 4.5-17.4 $cents/kWh range, which represent percentage savings of 30-84% if compared to diesel-powered and gridpowered systems.

In the last few decades, the demand for reversible heating and cooling systems has increased significantly, together with the need to generate energy in a more efficient and sustainable way. Consequently, the concept of solar photovoltaic (PV) powered heat pumps (HP) has become very attractive in order to match the heating/cooling demand with a renewable and environmentally-friendly energy source. This paper presents a review of the different solutions for PV-HP systems that have been studied theoretically and/or experimentally tested, and of the Key Performance Indicators (KPIs) that were mainly used. An analysis of these traditional KPIs has been performed and their boundaries were identified. As a result, new KPIs (PR25, PRref,25, SPFPV-HP and SPFPV-HP,ref,25) were proposed for trying to mitigate such limitations, as well as for evaluating not only the quality of the HP and the PV system, but also the quality of their integration and the renewable character of the whole PV-HP system. This paper is aimed to be framed in the common effort of the PV-HP research community to reach a set of KPIs that allow comparing the different future works and, therefore, a set of recommendations and future research lines are also proposed.

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The use of photovoltaic (PV) systems for powering heat pumps (HP) leads to an economic, energy efficient and environmentally friendly alternative for heating and cooling generation. A technical solution developed by the authors permits stand-alone configurations to operate without batteries, mitigating up to 75% of the solar power fluctuations resulting from cloud-passing. Once its technical feasibility has been demonstrated, the economic potential of this innovative solution should be assessed (avoiding a battery system is a significant advantage). This paper presents a comparative economic assessment of this autonomous (AU) solution and a self-consumption (SC) solution, that would substitute a grid-powered HP system for the space heating and cooling of two livestock farms located in Spain. Results show that PV-HP systems are economically feasible regardless of the technical solution: the Profitability Index (PI) is in the 2.23–2.97 €/€ range, the Internal Rate of Return (IRR) is in the 8.1–10.9% range, the Payback Period (PBP) is in the 9.2–11 years range and the savings in terms of the Levelized Cost of Energy (LCOE) are in the 57–70% range. The AU solution offers a higher economic profitability, because it permits larger savings in the electricity bill. The SC solution presents lower LCOEs because of its greater electricity production.